Advanced Search

Indexed by SCI、CA、РЖ、PA、CSA、ZR、etc .

Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
Display Method:
More catastrophic flow events may follow the Chamoli rock and ice avalanche under climate change
Haijun Qiu, Ya Liu, Bingzhe Tang, Ninglian Wang, Jiading Wang
 doi: 10.1007/s12583-024-1997-5
[Abstract](12) [PDF 1188KB](2)
A Study on the Genetic Dynamics and Development Characteristics of Granitic Rock Avalanches in the Northern Qinling Mountains, China
Yan Lyu, Ruixia Ma, Zuopeng Wang, Jianbing Peng, Tianzhuo Gu
 doi: 10.1007/s12583-024-0016-1
[Abstract](48) [PDF 2288KB](16)
Massive granitic rock avalanches are extensively developed in the middle section of the northern Qinling Mountains (NQM), China. The current consensus is that their formation could have been connected with seismic events that occurred in the NQM. However, there is a lack of systematic discussion on the genetic dynamics of these rock avalanches. Hence, taking Earth system scientific research as a starting point, this paper systematically summarizes and discusses development characteristics, formation times and genetic dynamic mechanisms of granitic rock avalanches in the NQM based on geological investigations, high-precision remote sensing interpretations, geomorphological dating, geophysical exploration, and a large-scale shaking table model test. We identified 53 granitic rock avalanches in this area, with a single collapse area ranging from 0.01×106 to 1.71×106 m2. Their development time can be divided into six stages, namely, 107297~106289 years BP, 11870-11950 years BP, 11666~10279 years BP, 2260-2320 years BP, 1788-1925 years BP, and 1392~1661 years BP, which were closely related to multiple prehistoric or ancient earthquakes. We suggest that long-term coupling of internal and external earth dynamics was responsible for the granitic rock avalanches in the NQM; the internal dynamics were mainly related to subduction, collision and extrusion of different plates under the Qinling terrane, leading to the formation and tectonic uplift of the Qinling orogenic belt; and the external dynamics were closely associated with climate changes resulting in mountain denudation, freeze‒thaw cycles and isostatic balance uplift. In this process, the formation and evolution of the Qinling orogenic belt play a geohazard-pregnant role, structural planes, including faults and joints, play a geohazard-controlled role, and earthquakes play a geohazard-induced role, which jointly results in the occurrence of large-scale granitic rock avalanches in the NQM. This research can not only decipher the genetic dynamic mechanism of large hard granitic rock avalanches but also reveal temporal and spatial patterns of the evolution of breeding and the generation of large-scale rock avalanches in the margins of orogenic belts.
Surveying organic matter, thermal maturity level, and paleo-environmental conditions by considering biomarker and stable carbon isotopic analysis
Meysam Hemmati, Yaser Ahmadi, Behzad Vaferi, Ali Hosin Alibak, David A. Wood
 doi: 10.1007/s12583-024-1984-x
[Abstract](98) [PDF 1351KB](51)
Biomarker and stable carbon isotope analyses are presented for the Garau formation of the Cretaceous age, an important source rock in western Iran, to reveal its potential as an oil-prone source rock. The C28/C29sterane ratio value range (0.72 to 0.83) of bitumen samples from the formation suggests that they were likely formed during phytoplankton blooms. Sterane, hopane, and isoprenoid/n-alkane ratios indicate that the formation's organic matter predominantly consists of algae, and bacteria, accompanied by some reworked material derived from higher plants. Due to the predominance of anoxic conditions and the actions of sulfate-reducing bacteria, the bitumen present is enriched with sulfur compounds. The percentages of saturates, aromatics, and nitrogen-sulfur-oxygen (NSO) fractions in the bitumen samples classify them as naphthenic oils. Isotope analysis reveals that biodegradation and water-washing have reduced the concentrations of some volatile saturates and low molecular weight aromatics in the bitumen samples. These actions have resulted in distinctive δ13C values for the formation's kerogen and bitumen fractions. The formation's organic matter has been subjected to high-temperature thermal regimes and has entered the oil-generation window at the sampled localities, with vitrinite reflectance (%RC) varying between 0.7 % and 0.75 %.
A potentially new early Ediacaran glaciation
Zhongwu Lan, Magdalena H. Huyskens, Rong Ren, Qing-Zhu Yin
 doi: 10.1007/s12583-024-1979-7
[Abstract](114) [PDF 1423KB](29)

Multiple episodes of Neoproterozoic glaciation, namely the Beiyixi, Altungol, Tereeken and Hankalchough glaciations, are recorded in the Kuruktag area of northeastern Tarim Craton, NW China. The Tereeken glaciation was previously correlated with the global Marinoan glaciation based on sedimentary and chemostratigraphic features recorded in the cap dolostone immediately overlying the glaciogenic diamictite, as well as less precise radiometric age constraints. In this study, we obtained chemical-abrasion isotope dilution isotope ratio mass spectrometry (CA-ID-IRMS) U-Pb age of 624.03 ± 0.1 Ma from zircons extracted from a tuff lava interbeded within the diamictite of the Tereeken Formation, which suggests an early Ediacaran age for the Tereeken glaciation. Such newly discovered early Ediacaran glaciation in the Tarim region could have induced the negative δ13Ccarb excursions between 625-605 Ma by providing oxygen and other oxidants to invoke remineralization of a deep ocean dissolved organic carbon (DOC) reservoir.

Detrital zircon U-Pb age analysis of Late Pliocene deposits from the lower Yangtze River, South China: Implications for sedimentary provenance and evolution of the Yangtze River
Xu Lin, Chang’an Li, Jing Liu-Zeng, Jovliet Marc, Haijin Liu, Lingling Li, Chengwei Hu, Xiaokang Chen, Jixin Chen
 doi: 10.1007/s12583-023-1961-9
[Abstract](249) [PDF 5297KB](73)
The Yangtze River, with a length of approximately 6,300 km, holds the distinction of being the largest river in East Asia that empties into the Pacific Ocean. Its formation is intricately linked to regional tectonic activity and climate fluctuations. However, the exact timeline for the formation of the Yangtze River remains elusive. This study investigates the provenance of the late Cenozoic strata in the Wangjiang Basin, situated in the lower Yangtze River, through the application of detrital zircon U-Pb dating. A total of seven sand samples were analyzed, leading to the identification of new U-Pb detrital zircon ages (n = 577). Our study reveals that the sand materials found in the Pliocene gravel beds of the Anqing Formation originate predominantly from the Yangtze River. The findings of our study, along with the provenance tracing of boreholes in the Yangtze River Basin and the shelf sea in East China, provide compelling evidence for the continuous presence of the Yangtze River throughout the Pliocene period. The development of the Yangtze River during the Pliocene is intricately connected to both the tectonic adjustments occurring at the southeastern margin of the Tibetan Plateau and the intensification of the Asian Monsoon.
Multi-scale structural geological model and quantification of stability evaluation for a high-steep fractured rock slope
Jia Wang, Wen Zhang, Donghui Chen, Han Yin, Junqi Chen
 doi: 10.1007/s12583-023-1953-9
[Abstract](105) [PDF 20246KB](41)
This study aims to evaluate the stability of a high-steep fractured rock slope on the right bank of Dongcuo River, Southeast Tibetan Plateau by establishing a multi-scale structural geological model. Multi-scale discontinuity information was first identified via the unmanned aerial vehicle photogrammetry. The multi-scale structural geological model for the cross section of the slope was established by multi-scale discontinuity processing. In particular, large-scale discontinuities were directly embedded into the model, medium-scale discontinuities were realized via discrete fracture network simulation technology, and small-scale discontinuities were implicitly considered in the equivalent rock parameter calculation. A staged scheme for searching the shortest paths of the multi-scale structural geological model via Dijkstra's algorithm was established. The searched shortest path with the largest discontinuity persistence passes the most fractures and processes the lowest shear strength, which can represent the critical slip surface (CSS). Three potential CSSs were selected for the quantification of the factor of safety (FOS) using the transfer coefficient method. Modified Jennings' criteria were proposed to estimate the equivalent shear strength of the CSS composed by rock bridges and discontinuities. Finally, FOS is calculated as 3.81, implying that the studied rock slope remains stable
First record of Middle Eocene elephant ancestors' footprints in the Gonjo Basin, East Tibet Plateau
TAHIR Asma, Huazhou Yao, KHAN Junaid, Yangui Li, He Zhao, Yue Yu
 doi: 10.1007/s12583-023-1946-6
[Abstract](74) [PDF 2407KB](25)
It is the first time that the fossil footprints of a group of middle Eocene elephant ancestors have been discovered in the Gonjo Basin, east Tibet Plateau. The Gonjo Formation is attributed to the middle Eocene epoch (U-Pb age = 44.7 ± 1.2 Ma) and consists mainly of purplish-red, medium- to coarse-grained sandstones, siltstones interbedded with mudstones, and conglomerates with sedimentary structures like ripple marks, rip-up clasts, and trough-cross bedding, suggesting fluvial-lacustrine systems. The group of fossil footprints has a characteristic oval-concave shape, and the toe impressions are absent. Some fossil footprints are overstepped with a pockmarked texture resembling Proboscipeda enigmatica. More than 165 fossil footprints of the group are relatively well-preserved with different diameters, which is evidence of highly social behavior and trackmakers of different ages, including calves, juveniles, adolescents, and adults. The size frequency of the fossil footprints enabled us to deduce the body mass, shoulder height, and hip-height distribution of the trackmakers that crossed the east Tibet Plateau 44.7 million years ago. The trackmakers comprised an estimated average hip-height of 111.8 cm, an average shoulder height of 172.8 cm for males/155.9 cm for females, and an average body mass of approximately 1218.1 kg for males/907.8 kg for females. The abundance of fossil footprints reveals that in the middle Eocene epoch, the environment was extraordinarily conducive for the elephant ancestors to live in the East Tibet region.
Investigation of oil content in lacustrine shale-oil systems: Insights from two different pyrolysis
YUPING WU, Chinglin Liu, Fujie Jiang, Tao Hu, Chenxi Zhang, Jiahao Lv, Renda Huang, Meiling Hu, Guanyun Wu, Rizwan Sarwar Awan
 doi: 10.1007/s12583-023-1814-6
[Abstract](925) [PDF 1935KB](69)
This research has investigated the oil content of lacustrine shale-oil systems from the Junggar Basin. Twenty-eight samples are used for different pyrolysis experiments to study the characteristics of shale oil occurrence and the difference between various evaluation methods. Additionally, the factors affecting the physical states of shale oil are discussed. Compared with the standard Rock-Eval, the two-step pyrolysis and multi-step pyrolysis can eliminate the influence of the carryover effect. Therefore, these two types of pyrolysis are used to obtain the total, free, and adsorbed oil yield of the shale. The results demonstrate that the total oil yield acquired by multi-step pyrolysis is quite similar to that obtained by two-step pyrolysis. Both of them can prevent the retained oil yield from being underestimated by more than 50%. However, the free oil yield obtained by multi-step pyrolysis is significantly higher than that obtained by two-step pyrolysis. The multi-step pyrolysis can easily exaggerate the real free oil yield in resource evaluation. Therefore, this article suggests using the two-step pyrolysis to evaluate the characteristics of petroleum in shales. Furthermore, the amount of hydrocarbons within shales is related to organic matter properties. The higher the organic matter richness, the higher the total/adsorbed oil yield within the shale before reaching the adsorption saturation. The better the kerogen type, the higher the amount of liquid hydrocarbons within shales. As the thermal evolution of shales increases, the free oil proportion and the mobility of petroleum increase. This study compared different pyrolysis methods, which provided new insight for obtaining the oil content of shales, a key parameter of shale oil resource evaluation.
Application of unmanned aerial vehicle remote sensing on dangerous rock mass identification and deformation analysis: case study of a high-steep slope in an open pit mine
Wenjie Du, Qian Sheng, Xiaodong Fu, Jian Chen, Jingyu Kang, Xin Pang, Daochun Wan, Wei Yuan
 doi: 10.1007/s12583-023-1813-7
[Abstract](404) [PDF 4237KB](113)
Source identification and deformation analysis of disaster bodies are the main contents of high-steep slope risk assessment, the establishment of high-precision model and the quantification of the fine geometric features of the slope are the prerequisites for the above work. In this study, based on the UAV remote sensing technology in acquiring refined model and quantitative parameters, a semi-automatic dangerous rock identification method based on multi-source data is proposed; In terms of the periodicity UAV-based deformation monitoring, the monitoring accuracy is defined according to the relative accuracy of multi-temporal point cloud. Taking a high-steep slope as research object, the UAV equipped with special sensors was used to obtain multi-source and multi-temporal data, including high-precision DOM and multi-temporal 3D point clouds. The geometric features of the outcrop were extracted and superimposed with DOM images to carry out semi-automatic identification of dangerous rock mass, realizes the closed-loop of identification and accuracy verification; changing detection of multi-temporal 3D point clouds was conducted to capture deformation of slope with centimeter accuracy. The results show that the multi-source data-based semi-automatic dangerous rock identification method can complement each other to improve the efficiency and accuracy of identification, and the UAV-based multi-temporal monitoring can reveal the near real-time deformation state of slopes.
Organic matter occurrence and its effects on pore structure and methane adsorption capacity capacity: A case study of the Niutitang black shale in Guizhou, China
Peng Xia, Fang Hao, Jinqiang Tian, Yong Fu, Chuan Guo, Zhen Yang, Yuliang Mou, Ke Wang
 doi: 10.1007/s12583-022-1688-z
[Abstract](1228) [PDF 5313KB](95)
The black shale samples from the Niutitang Formation in the Yangtze Block were sequentially treated using organic solvent extraction and wet chemical oxidation. The organic matter (OM) in the shales includes physically mobile OM (PmOM), chemically mobile OM (CmOM), and stable OM (StOM). The CmOM has the strongest CH4 adsorption capacity because it has the largest volume of micropores and mesopores. In contrast, the PmOM has a very negative effect on the CH4 adsorption because it is poreless. The XD shale is a siliceous shale, in which the quartz particles wrap partly OM, preventing extraction and oxidation. The SL shale is an argillaceous shale, in which most of the OM is combined with clay minerals to form organo-clay composites. In both the SL and XD shales, the OM that is extractable via organic solvents is distributed among the mineral particles and is interconnected. The conceptual model of marine black shale in different environments needs to be perfected in the future because quantitative and qualitative methods should be combined to clarify the relationship between the known OM types (e.g., pyrobitumen, solid bitumen, and solid kerogen) and the OM types identified in this study.
Multivariate statistical analysis of dominating groundwater mineralization and hydrochemical evolution in Gao, northern Mali
TRAORE ADIARATOU, Xumei Mao, Alhousseyni Traore, YAHAYA YAKUBU, Aboubacar Sidibe
 doi: 10.1007/s12583-022-1689-y
[Abstract](240) [PDF 1783KB](39)
Population growth and expanding urbanization have caused persistent shortages and contamination of groundwater resources in Mali, Africa. The increase in groundwater salinity makes it more difficult for residents to obtain drinking water, it is necessary to clarify the causes and control factors of groundwater mineralization in Gao region, northern Mali. Based on the analysis of the hydrochemical composition of groundwater in 24 boreholes, Piper and Schöeller diagrams, principal component analysis (PCA) and hierarchical cluster analysis (HCA) are used to carry out multivariate statistical analysis on the main ions. The results show that the groundwater samples are weakly alkaline, with pH values ranging from 5.83 to 8.40, and the average values of boreholes are 7.50, respectively. The average electrical conductivity (EC) value is 354.4 (µS/cm), and the extreme value is between 124.0 and 1247 (µS/cm). Water is usually mineralized and presents nine types of water phase. The three principal components explain 84.42% of the total variance for 13 parameters. The factor F1 (58.85%), the factor F2 (16.88%) and the factor F3 (8.69%) present for the majority of the total data set. In addition, multivariate statistical analysis confirmed the genetic relationship among aquifers and identified three main clusters. Clustering related to groundwater mineralization (F1), clustering related to oxide reduction and iron enrichment (F2), and clustering of groundwater pollution caused by nitrate and magnesium (F3). We found that agriculture, weathering activities and dissolution of geological materials promote the mineralization of groundwater. Groundwater quality in the Gao region is becoming less and less potable because of increasing salinity.
Spatial and temporal evolution of lithospheric mantle beneath the eastern North China Craton: Constraints from mineral chemistry of peridotite xenoliths from the Miocene Qingyuan basalts and a regional synthesis
Jian-Fang Guo, Qiang Ma, Jianping Zheng, Yuping Su
 doi: 10.1007/s12583-022-1691-4
[Abstract](190) [PDF 5165KB](59)
Mineralogical data are presented for the peridotite xenoliths from Miocene (~19Ma) Qingyuan basalts in the eastern North China Craton (NCC), with the aim of constraining on property of the sub-continental lithospheric mantle (SCLM) beneath the northern Tan-Lu Fault zone (TLFZ) during the Cenozoic. The Qingyuan peridotites are dominated by spinel lherzolites with moderate-Mg# olivines (89.4 to 91.2), suggesting that the regional SCLM is mainly transitional and fertile. Light rare earth element (LREE)-depleted, slightly depleted and enriched clinopyroxenes (Cpx) are identified in different peridotites. Chemical compositions of the LREE-enriched Cpx and the presence of phlogopite suggest that the Qingyuan SCLM has experienced silicate-related metasomatism. The synthesis of available mineral chemical data of the mantle xenoliths across the NCC confirms the SCLM beneath the NCC is highly heterogeneous in time and space. The Mesozoic-Cenozoic SCLM beneath the TLFZ and neighboring regions are more fertile and thinner than that beneath the region away from the fault zone. The fertile and refractory peridotite xenoliths experienced varying degrees of silicate and carbonatite metasomatism, respectively. The spatial-temporal lithospheric mantle heterogeneity in composition, age and thickness suggest that the trans-lithosphere fault zone played an important role in heterogeneous replacement of refractory cratonic lithospheric mantle.
Limitation of the Application of Heat Tracer in Investigating Groundwater and River Interactions under Dynamic Flow Conditions
Mengyan Ge, Rui Ma, Ziyong Sun
 doi: 10.1007/s12583-022-1683-4
[Abstract](160) [PDF 3970KB](26)
The groundwater (GW) in the floodplain riparian area frequently interacts intensely with surface water (SW). Heat as a tracer is one of the hot research fields in investigating GW-SW interactions, and analytical approaches have been proposed for the calculation of exchange flow velocity. However, few studies have considered the effects of very dynamic flow conditions and monitoring instrumentation on the calculation with field measured data. Herein, taking the middle reaches of the Heihe River as the study area, different types of monitoring wells were constructed under the riverbed and near the river, and multiple methods (Darcy’s law, heat tracing, and isotopic mixing methods) were employed to trace the exchanges between the river and groundwater. The results indicate that different methods demonstrate diverse information with obvious unevenly distributed flux along the vertical direction. And the combination of multiple methods has an important role in studying the interaction between GW and SW. Fully screened wells produce intraborehole flow and disturb the heat transport, which is relevant to flow velocity, and further affects the temperature distribution, impacting the temperature-based flow velocity calculation. Dynamic flow conditions aggravate riverbed sediment disturbances, e.g., scour and deposition, and additionally affect the interaction and monitoring data.
Geochemical Modeling of Fluid–Rock Interactions in Shallow buried Carbonate Reservoirs based on the Water Bath Instrument
Jiayi Ma, Anjiang Shen, Shuyun Xie, Min She, Huayun Tang, Emmanuel M. CARRANZA, Tianfu Zhang
 doi: 10.1007/s12583-022-1690-5
[Abstract](174) [PDF 2439KB](26)
Fluid–rock interaction plays a critical function in physical and chemical processes associated with the formation and evolution of oil and gas reservoir space. In the diagenetic stage of shallow burial, the dissolution of carbonate rocks by acidic fluids is conducive to the development of secondary pore space in reservoirs. In contrast, the free drift experiment based on water bath instrument can simulate the dissolution process of carbonate rocks in shallow burial environment effectively. In order to study the shallow burial dissolution mechanism of carbonate rocks in different acid solutions, 14 samples of typical carbonate rocks of Sinian, Cambrian, Ordovician, Permian and Triassic ages in the Tarim and Sichuan Basins, China were used. The dissolution experiments on carbonate rocks in sulfuric acid, acetic acid, hydrochloric acid, silicic acid and carbonic acid at shallow burial temperature (30℃≤T≤90℃) were carried out using a water bath instrument. The PHREEQC software was used to simulate the dissolution of carbonate minerals, in order to compare the results of constant temperature water bath experiment. The results show that acid solutions have significant dissolution effect on shallow burial carbonate rocks when T = 50–60℃, which corresponds to the burial depth of 1500–2000 m in the Tarim Basin and 1110–1480 m in the Sichuan Basin. However, there were obvious differences in the dissolution and reformation of carbonate rocks in different acids. In particular, sulfuric acid solution produced by thermochemical sulfate reduction can significantly promote the dissolution of carbonate rocks, especially dolomitic limestone. Moreover, the dissolution of limestone reservoirs is stronger than that of dolomite reservoirs in shallow burial. The results will provide new insights into the study of dissolution laws and influencing factors of carbonate reservoir space and the evaluation and prediction of carbonate reservoir in China.
Chronology, geochemistry and isotopic compositions of the Cretaceous Zhangjiakou diabase: Magmatic derivation and geodynamic implications
peng li, Dazhao Wang, guanzhong shi
 doi: 10.1007/s12583-022-1684-3
[Abstract](159) [PDF 6259KB](27)
Zircon U–Pb ages, major and trace elements and Sr–Nd–Hf isotope data of the diabase in the Zhangjiakou district were studied to investigate its derivation and tectonic implications. Zircon U–Pb ages indicate that the diabase was emplaced at ~130 Ma or younger, and captured zircons cluster at ~147 Ma, ~240 Ma, ~430 Ma and ~465 Ma. The diabase is characterized by minor variations in SiO2 (49.35–52.10 wt.%), TiO2 (1.65–1.77 wt.%), Al2O3 (17.00–18.26 wt.%), MgO (4.28–4.93 wt.%), CaO (6.69–7.90 wt.%) and Mg# (48–54). It has no significant Eu anomaly and displays enrichment in large ion lithophile elements (Rb, Ba and Sr) and depletion in high field strength elements (Nb, Ta, P and Ti). The diabase exhibits homogeneous Sr ((87Sr/86Sr)i = 0.70606–0.70701) and Nd (εNd(t) =–13.6 to –13.2) isotopic compositions. These features suggest that the parental magma was derived from partial melting of the ancient lower crust, relating to mantle upwelling that triggered by stagnant slabs or lithospheric detachment associated with the westward subduction of the Paleo-Pacific Plate. The Early Paleozoic inherited igneous zircons in the diabase suggest that the northern margin of the North China Craton (NCC) likely underwent southward subduction of the Paleo-Asian Ocean.
Characteristics of connected pores and evaluation of shale oil mobility in the Qianjiang Formation, Qianjiang Sag, Jianghan Basin,China
SUN Zhongliang, LI Zhiming, HE Chencheng, ZHU Feng, SHEN Baojian, LU Longfei
 doi: 10.1007/s12583-022-1699-9
[Abstract](402) [PDF 2527KB](38)
The connectivity of shale pores and the occurrence of movable oil in shales have long been a focus of research. In this paper, samples from Wells BX7 and BYY2 in the Eq34-10 cyclothem of Qianjiang Formation in the Qianjiang Depression, were analyzed. A double mercury injection method was used to distinguish between invalid and effective connected pores. The pore characteristics for occurrence of retained hydrocarbons and movable shale oil were distinguished based on comparison of pore changes in low temperature nitrogen adsorption and high pressure mercury injection experiments before and after extraction and the change in the mercury injection amounts in the pores between two separate mercury injections.. The results show that less than 50% of the total connected pores in the Eq34-10 cyclothem samples are effective. The development of effective connected pores affects the mobility of shale oil but varies with different lithofacies. The main factor limiting shale oil mobility in Well BX7 is the presence of pores with throat sizes less than 15nm. In Well BYY2, residual mercury in injection testing of lamellar dolomitic mudstone facies was mainly concentrated in pores with throats of 10~200 nm, and in bulk argillaceous dolomite facies it was mainly concentrated at 60~300nm. The throats of hydrocarbon-retaining pores can be 5nm or even smaller, but pores with movable shale oil in the well were found to have have throat sizes greater than 40nm. Excluding the influence of differences in wettability, the moveability of shale oil is mainly affected by differences in lithofacies, the degree of pore deformation caused by diagenesis, the complexity of pore structures, and the connectivity of pore throats. Dissolution and reprecipitation of halite also inhibit the mobility of shale oil.
Formation Mechanism of the Paleocene basal conglomerate, southwest Tarim Basin
yong Yue, Jingchun Tian, Chuanyan Huang
 doi: 10.1007/s12583-022-1696-z
[Abstract](157) [PDF 8039KB](22)
Abstract: Most knowledge about the Cretaceous-Paleogene strata in the Tarim Basin is mainly inferred from the outcrops at the basin’s margin,but first time in the basin. The formation mechanism of the Paleocene basal conglomerate was determined using geochemical isotopes of the breccia from well PBX1 in the southwestern Tarim Basin. The results showed that the global K/Pg (i.e., Cretaceous/Paleogene) clay layer boundary was located in the middle of the Paleocene basal conglomerate at the depth of 7066.75m in well PBX1. In the Late Cretaceous, associated with volcanic activities and earthquakes, the caldera in the PBX1 well block formed an annular depression with large elevation differences in response to the Pamir block collision. As a result, the collapsed breccia with storm tide genesis deposited at the periphery and inside of the depression, characterized by syn-sedimentary deformation. During the Paleocene, multiple sets of interbedded carbonate and collapsed breccia deposited in response to multi-phased transient transgression-regression cycles. The transportation of breccia exhibited near-source accumulation/extremely close or in-situ rapid accumulation. The studied region is located in the eastern end of the Tethys Sea, the Late Cretaceous-Early Paleocene breccia is of great significance for reconstructing the paleogeography of the Tarim basin in Tethys. Key words: South-western Tarim;Paleogene system;Breccia;Attribution and genesis
Contrasting behavior for Li-Mg isotopes during subduction: Insights from garnet in the Yardoi schists, Tibet
Xing Li, Yilin Xiao, Olivier Nadeau, Dongyong Li, Haiyang Liu, Zhang Zeming, Zhenhui Hou
 doi: 10.1007/s12583-022-1697-y
[Abstract](232) [PDF 4022KB](66)
It has long been recognized that garnet has the capacity to preserve the trace element and isotopic signature of distinct metamorphic growth zones because of its high closure temperature. Combined with the large size of certain garnet porphyroblast, this allows investigating variations in metamorphic conditions such as pressure, temperature, deviatoric stress, and fluid composition, which occur during subduction-related metamorphism. Here, one garnet porphyroblast of 6 cm diameter was sampled from the Yardoi schists of Tibet, and the major-, trace-, and Li-Mg isotopic compositions of distinct growth zones were determined in situ. The δ7Li values range from +6.0 ‰ to +4.1 ‰ and follow ‘S-shape’ patterns on both sides of the garnet’s core, revealing a two-stage growth process corresponding to the fluid-assisted sequential recrystallization of chlorite and micas during prograde metamorphism. By contrast, once corrected for the overprinting by retrograde metamorphism, the δ26Mg values vary monotonously from -1.73 ‰ in the core to -1.32 ‰ in the outer rim, reflecting a single-step process interpreted to result from increasing temperature and the solid-state recrystallization of chlorite-biotite during prograde metamorphism. This different behavior of Li and Mg isotopes is interpreted to result from the fact that Li is more fluid-mobile than the major element Mg.
Provenance of the southeastern South China Block in the Late Triassic and initiation of Paleo-Pacific subduction: Evidence from detrital zircon U–Pb geochronology
Jintao Kong, zhongjie Xu, Rihui Cheng, Duo Wan
 doi: 10.1007/s12583-022-1694-1
[Abstract](137) [PDF 7438KB](23)
During the late Paleozoic–early Mesozoic era, the sediment transport system and tectonic regime in the southeastern margin of the South China Block (SESCB) all changed, significantly affected by the Paleo-Pacific subduction. This study uses detrital zircon geochronology to discuss the Late Triassic source-to-sink system in the SESCB and provides some references for the Paleo-Pacific subduction process. The paleogeography and similarity of detrital zircon age distribution reveal three sinks in the SESCB during the Late Triassic: 1. the Yangchun–Kaiping–Gaoming area, comprising major age ranges of 260–220, 460–400, and 1,200–800 Ma, which might be sourced from the Yunkai Terrane; 2. the Jiexi–Kanshi–Nanjing area, characterized by the significant age component of 2,000–1,800 Ma, which corresponded to the Wuyi Terrane; 3. the Xinan area, consisting of significant age groups of 290–250 Ma and 380–320 Ma, which might be sourced from the magmatic rocks formed by the Huinan Movement and Paleo-Pacific subduction. The Upper Triassic strata contain many 290–250 Ma zircons, and their trace elements suggested a magmatic arc existed near the SESCB during the 290–250 Ma. Thus, we propose that the Paleo-Pacific subduction might have begun in the Early Permian.
Ore geology, H–O–C isotopes and 40Ar–39Ar dating of the Wutonggou iron deposit, eastern Tianshan, NW China: Implications for the source, timing, and genesis of hydrothermal mineralization in a sedimentary iron deposit
Chun-Long Wang, Yi‑Tian Wang
 doi: 10.1007/s12583-022-1686-1
[Abstract](191) [PDF 6300KB](37)
The Wutonggou iron deposit is located in the well-known iron metallogenic belt in the eastern Tianshan, NW China, and has been regarded as a sedimentary iron deposit. Hydrothermal overprinting could play indispensable roles in the formation of high-grade iron ores in sedimentary iron deposits, thus the nature and evolution of hydrothermal fluids have important implications on the genesis of these deposits. Consequently, an integrated study of ore geology, H–O–C isotopes and 40Ar–39Ar dating, is conducted on the Wutonggou deposit, in order to reveal the features, source, and timing of hydrothermal mineralization. The studied deposit includes two mining sections namely the Jianshan and Wutonggou. The δ18O values of early magnetite from the Jianshan section range from +3.0‰ to +5.8‰ that nearly consistent with classic magmatic magnetite, while increase to 6.3‰–8.0‰ in the late stage. Quartz from the two sections shows comparable H–O isotopic compositions and identical fractionation trends, and is plotted in or periphery to the primary magmatic water area. Calcites from the two sections are broadly similar in carbon and oxygen isotopic compositions, and siderite from the Wutonggou section is plotted in the same region. Thus, comparable stable isotopic compositions and evolution trends indicate similar magmatic fluids contributed hydrothermal iron mineralization in the two mining sections. Moreover, water-rock interactions of varying degrees generated distinct mineralization styles in the Jianshan and Wutonggou sections, and caused the isotopic fractionation in late stages. Biotite extracted from a hydrothermal siderite ore yielded a 40Ar–39Ar plateau age of 299.5 ± 2.0 Ma, indicating the timing of hydrothermal iron mineralization is corresponding to the emplacement of vicinity granitoids. Taken together, the hydrothermal mineralization in the Wutonggou iron deposit was the product of remobilization and upgrading of early sedimentary iron ores, and ore-forming fluids were most probably originated from regional granitic magmatism.
Characteristics and formation analysis of earth fissure in Anren area in Wei River Basin, China
Jianwei Qiao, Zhenjiang Meng, Yuyun Xia, Cong Liu, Quanzhong Lu, Feiyong Wang, Yuanqiang Zhou, Haiyuan Zhao
 doi: 10.1007/s12583-022-1653-x
[Abstract](313) [PDF 3547KB](25)
Since the 1950’s, 212 earth fissures have been discovered in the Wei River Basin. During a field survey in 2016, an additional 48 earth fissures were discovered in Anren area, northeast of the Wei River Basin. The characteristics and formation mechanisms of these fissures were studied through field investigations, measurements, trench excavation, and drilling. On-site investigations indicated that these earth fissures were distributed along a fault-controlled geomorphic boundary. Fissures trended at 60°–80° NE and were divided into five groups. Trenches revealed multiple secondary fissures, exposing severe soil ruptures in the shallow earth surfaces. Drilling profiles revealed that earth fissures dislocated several strata, and resembled synsedimentary faults. Seismic reflection profiles revealed buried faults beneath the earth fissures. The Anren area fissures formed in the following three stages: regional extension that initially generated multiple buried faults; seismic activity rupturing multiple strata, resulting in multiple buried fractures; and finally, erosion processes that propagated the buried fractures to the surface, forming the current earth fissures.
Geochronology and geochemistry of Permian Dashizhai Basin in Xing’an–Inner Mongolia Orogen: Implications for the evolution of the Paleo-Asian Ocean
Chi Zhang, Guosheng Wang, Zhiguang Zhou, Shen Gao, Neng Zhang, Liudong Wang, Erqiang Bo
 doi: 10.1007/s12583-022-1651-z
[Abstract](162) [PDF 21807KB](30)
The Xing’an–Inner Mongolia Orogen is a critical tectonic unit for constraining the evolution of the Paleo-Asian Ocean. However, the location and time for the closure of the Paleo-Asian Ocean are still debated. Here, we select a representative basin in Dashizhai in northeastern China, using U-Pb zircon geochronology and geochemistry to analyze the sedimentary facies, depositional ages, and provenance. The results show that the age of the Dashizhai Formation range from 400 to 347 Ma, the Shoushangou Formation range from 400 to 348 Ma, the Zhesi Formation range from 307 to 252 Ma, and the Linxi Formation range from 299 to 241 Ma. The Dashizhai Formation is composed of metamorphic andesite and clastic rocks. The Shoushangou Formation comprises siltstone, rhyolite, and argillaceous siltstone. The Zhesi and Linxi Formations are composed of mudstone and argillaceous siltstone. Geochemical data shows that these rocks are enriched in light rare earth elements and depleted in Eu with various La/Sc, Th/Sc, and La/Co ratios. The Permian Dashizhai Basin is from Permian volcanic and felsic igneous rocks from the Ergun, Xing’an, and Songliao blocks. The absence of the Late Carboniferous strata in the Dashizhai Basin indicates an extension setting during this period. Furthermore, we suggest the Xing’an–Inner Mongolia Orogen was an uplifting process associated with evolution the Paleo-Asian Ocean during the Late Permian.
3D Distinct Element Back Analysis Based on Rock Structure Modelling of SfM Point Clouds: The Case of the 2019 Pinglu Rockfall of Kaili, China
Zhen Ye, Qiang Xu, Qian Liu, Xiujun Dong, Feng Pu
 doi: 10.1007/s12583-022-1667-4
[Abstract](164) [PDF 9435KB](25)
This paper introduces the use of point cloud processing for extracting 3D rock structure and the 3DEC -related reconstruction of slope failure, based on a case study of the 2019 Pinglu rockfall. The basic processing procedure involves: (1) computing the point normal for HSV-rendering of point cloud; (2) automatically clustering the discontinuity sets; (3) extracting the set-based point clouds; (4) estimating of set-based mean orientation, spacing, and persistence; (5) identifying the block-forming arrays of discontinuity sets for the assessment of stability. The effectiveness of our rock structure processing has been proved by 3D distinct element back analysis. The results show that SfM modelling and rock structure computing provides enormous cost, time and safety incentives in standard engineering practice.
Late Miocene elevated horizontal karst caves and landform evolution as a response to tectonic uplift along with regional integration of fluvial drainage in Southwestern China
Min Zhai, Xinggong Kong, Yuanhai Zhang, Philip Rowsell, Zhijun Zhao, Baojian Huang, Jing Zhang
 doi: 10.1007/s12583-022-1656-7
[Abstract](279) [PDF 14363KB](23)
In Southwestern China, the development of karst landforms and the planation surfaces is closely related to local tectonics, fluvial incision and base level change, as well as climate change. While researches on when these karst landforms and planation surfaces formed and how they evolved along drainage development are scarce. Fortunately, horizontal caves with numerous fluvial deposits in high karst mountains can be used as time markers in landform evolution. Here we select large horizontal caves to perform studies of geomorphology, sedimentology and geochronology. Field work shows that more than 25 km long horizontal cave passages are perched 1500 m higher than the local base level, but filled with several phases of fluvial sediments and breakdown slabs. The first phase of fluvial gravels and related cave drainage were dated back to 6.4 Ma using cosmogenic nuclide burial dating, and the stalagmite covering the cave collapse was dated by the U-Pb method , older than 1.56 Ma. These results show that the continuous horizontal cave drainage system and the planation surface were developed prior to the Late Miocene. The lowering process of the base level as a result of the sharp fluvial incision and water level lowering, along with the regional uplift, led to the abandonment of the horizontal cave and the elevated planation surface at the Late Miocene . After that, the phase of cave collapse , thick fluvial sand and clay sediments in the caves from the recharge of the cave deposited at around 1.6 Ma and during the Middle Pleistocene, respectively. Subsequently, speleothems widely deposited on the collapse and clay sediment during the period from 600 to 90 ka ,whereas the deposition of cave fluvial sediments terminated suddenly. The tectonic could control the denudation of surface caprock and the development of karst conduits prior to the Late Miocene, whereas the river incision acted as the main driver for the base level lowering and the destruction of the horizontal cave drainage at high altitude. In addition, the rapid incision and the retreat of Silurian gorges finally caused the formation of karst mesa in the Middle Pleistocene.
Source-to-sink relationships between the Qaidam Basin (North Tibet) and its surrounding mountain ranges: New insights from detrital zircon U–Pb ages in modern river sediments
Xu Zhang, Bowen Song, Tinglu Yang, Yafei Hou, Yibo Yang, Keke Ai, Jiaxuan Wang, Zhang Kexin
 doi: 10.1007/s12583-022-1666-5
[Abstract](286) [PDF 7269KB](49)
The Cenozoic source-to-sink history of the Qaidam Basin is crucial for understanding of the basin-filling architecture, mountain-building processes and even the dynamics of the Tibetan plateau growth. However, the provenance history of Cenozoic strata in the Qaidam Basin remains ambiguous, especially in the northern Qaidam Basin. This controversy highlights the importance of obtaining the spatial source-to-sink relationships between the Qaidam Basin and its surrounding mountain ranges. In this study, we investigated the detrital zircon U–Pb ages of modern fluvial systems draining the Eastern Kunlun Shan. Their detrital zircon age distributions fall into five age groups: 300-190, 530-360, 1000-560, 2000-1100 and 2650-2000 Ma. The dominant age groups are 530-360 and 300-190 Ma, which represent the successive subduction of the Proto-Tethys and Paleo-Tethys Oceans and the subsequent continental collisions, respectively. Combining these new detrital zircon U–Pb ages with available age datasets, we finally obtained complete detrital zircon age information for modern fluvial systems in the whole Qaidam Basin. The U–Pb age distributions of modern river sands reveal that the zircon age signature of basement rocks in the Eastern Kunlun Shan is significantly different from that in the South Qilian Shan but is similar to that in the Altyn Tagh Shan. Moreover, these zircon age observations were confirmed by the significant difference in the Nd isotopic signature of modern river sands, which reveals a significant difference between the Eastern Kunlun Shan and South Qilian Shan in the formation and evolution process.
Karst trough control of solute transport processes at two karst groundwater flow systems, Western Hubei, Central China
Yi'an Wang, Ruichao Zhao, Lin Ding, Shuai Xiong, Yin Li, Jianwei Bu, Wei Chen, Hong Zhou, Wei Liu
 doi: 10.1007/s12583-022-1665-6
[Abstract](342) [PDF 3313KB](66)
To investigate groundwater flow and solute transport characteristics of the karst trough zone in China, tracer experiments were conducted at two adjacent typical karst groundwater flow systems (Yuquandong (YQD) and Migongquan (MGQ)) in Sixi valley, western Hubei, China. High-resolution continuous monitoring was utilized to obtain breakthrough curves (BTCs), which were then analyzed using the multi-dispersion model (MDM) and the two-region nonequilibrium model (2RNE) with basic parameters calculated by CXTFIT and QTRACER2. Results showed that: (1) YQD flow system had a complex infiltration matrix with overland flow, conduit flow and fracture flow, while the MGQ flow system was dominated by conduit flow with fast flow transport velocity, but also small amount of fracture flow there; (2) they were well fitted based on the MDM (R2=0.928) and 2RNE (R2=0.947) models, indicating that they had strong adaptability in the karst trough zone; (3) conceptual models for YQD and MGQ groundwater systems were generalized. In YQD system, the solute was transported via overland flow during intense rainfall, while some infiltrated down into fissures and conduits. In MGQ system, most were directly transported to spring outlet in the fissure-conduit network.
Physical prediction model of compound hydrodynamic unload-load response ratio and its application in reservoir colluvium landslide
Lu Guo, Keqiang HE, Honghua Liu, Fandi Meng, Xuchun Wang
 doi: 10.1007/s12583-022-1662-9
[Abstract](115) [PDF 1406KB](14)
It is well known that the deformation and damage of reservoir colluvium landslides are often determined by the combined dynamics of reservoir water level change and rainfall. Based on the systematic analysis of the change law of reservoir water level, rainfall and displacements of reservoir colluvium landslide, this paper proposes the compound hydrodynamic action of rainfall and reservoir water as the unload-load parameter, and the landslide displacement as the unload-load response parameter. Based on this, a physical prediction model of the compound hydrodynamic unload-load response ratio of reservoir colluvium landslide was established, and the quantitative relationship between the compound hydrodynamic unload-load response ratio and its stability evolution was in-depth analyzed and determined. On the basis of the above research, taking Shuping landslide, a typical hydrodynamic pressure landslide as an example, the unload-load response ratio model is used to systematically evaluate and predict the stability evolution law and the change trend of the landslide under compound hydrodynamic action. The prediction result shows that the variation law of the compound hydrodynamic unload-load response ratio is consistent with the dynamic evolution law of its stability. Therefore, the above studies show that the compound hydrodynamic unload-load response ratio parameter is an effective displacement dynamic evaluation parameter for reservoir colluvium landslides, so it can be used in the prediction of the reservoir colluvium landslides.
Effect of the tectonic inversion on the Source-to-sink system evolution in a lacustrine rift basin, a case study of South Yellow Sea Basin, East China.
Xue Fan, Chao Fu, Shengli Li, Shunli Li
 doi: 10.1007/s12583-022-1664-7
[Abstract](159) [PDF 10495KB](32)
The complex plate collision process led the South Yellow Sea Basin (SYSB) to go through an intensity tectonic inversion during the early Cenozoic, which led to a regional unconformity surface development. As a petroliferous basin, SYSB saw intensity denudation and deposition process, making it hard to characterize their source-to-sink system(S2S), and this study provided a new sight to reveal them quantitatively. According to the seismic interpretation, it was found that two types of tectonic inversion led to the strata shortening process, which was classified according to their difference in planar movements, dip-slip faults, and strike-slip ones. As for dip-slip faults, the inversion structure was primarily formed by the dip-slip movement and many fault-related folds developed, which mainly developed in the North Depression Zone of the SYSB. The strike-slip ones, accompanying developed with some negative flower structures, are dominated in the South Depression Zone of the SYSB. Then, to reveal its source-to-sink system in the tectonic inversion basin, we speculated the sediments’ provenance area and their migration distance, referring to the zircon U-Pb data and heavy mineral assemblage. As for the North Depression Zone, it is shown that fewer distal sediments from the West Sulu Orogenic Belt are infilled, and proximal slump or fan delta are prominently developed during the tectonic inversion stage. The provenance rebuild in the South Depression Zone shows increasing sediments from the proximal area (Central Uplift Zone in SYSB and Wunansha Uplift) and the prograding delta long-axis parallel to these boundary faults during the tectonic inversion stage. Calculations were conducted on the coarse sediments content, faults displacements, catchment relief, sediments migration distance, and discussions about the impact factors to the Source-to-sink system developed in various strata shortening patterns with a statistical method. It was found that, within the dip-slip faults-dominated zone, the volume of the sediment routing system and the ratio of coarse-grained sediments merely has a relationship with the amount of sediment supply and average faults broken displacement. Compared with the strike-slip faults-dominated zone, the source-to-sink system shows a lower level of sandy sediment influx, and its coarse-grained content is mainly determined by the average faults broken displacement.
System reliability analysis of reservoir landslides: Insights from long-term reservoir operation
Kang Liao, Yiping Wu, Fasheng Miao
 doi: 10.1007/s12583-022-1668-3
[Abstract](196) [PDF 4819KB](33)
The reservoir operation awakens numerous landslides with multiple sliding surfaces known as reservoir landslides, and the systematic stability analysis for such landslides is becoming increasingly urgent. Taking the Majiagou landslide as an example, this paper analyses the comprehensive performance of the landslide from a probabilistic point of view. Under a reservoir operation cycle, a series of numerical analyses are carried out to simulate the migration of the seepage field, then the dynamic stability of the landslide is quantified accordingly. Subsequently, the wetting-drying cycles test is used to model the weakening of strength parameters in hydro-fluctuation belt under the long-term reservoir operation. Considering the weakening effect of long-term reservoir operation on the hydro-fluctuation belt, the system reliability is evaluated using the Ditlevsen's bounds. The results suggest that the reservoir operation can affect the stability of the landslide by changing the seepage field. The system failure probability gradually rises as the number of wetting-drying cycles increases. Compared with conventional probabilistic analysis that calculates the failure probability of each sliding surface mechanically, analyzing the landslide in terms of system reliability can effectively narrow the failure probability range, which provides an insightful idea for evaluating the systematic stability of analogous reservoir landslides.
Mechanism of interaction between anchored slide-resistant piles and landslides with weak-hard interbedded bedrock:model tests and theoretical interpretation
Guihua Wang, Changdong Li, Xin He, Taijiang Chen, Jie Meng, Wenmin Yao, Yongquan Zhang, HUAWEI ZHANG
 doi: 10.1007/s12583-022-1663-8
[Abstract](310) [PDF 3551KB](19)
Interactions between anchored slide-resistant piles and landslides with weak-hard interbedded bedrock have not yet been systematically studied. Physical models of landslides reinforced by anchored slide-resistant piles are investigated based upon the self-developed testing system. The landslide system evolution with increasing loading force is revealed; the internal force and deformation of anchored slide-resistant piles in weak-hard interbedded bedrock are analyzed. A single anchored pile in weak-hard interbedded bedrock is analyzed theoretically, and an optimized calculation method for the axial force of the anchor cable is proposed. The results show that (1) The landslide system evolves through four stages: creeping, coordinated deformation, uncoordinated deformation, and failure. (2) The thrust sharing ratio of the pile-anchor first increases, then decreases slightly, and finally stabilizes; the maximum thrust sharing ratio is 12.22. (3) The anchoring force provided by weak-hard interbedded bedrock is between those of homogeneous hard and homogeneous weak rocks. The horizontal displacement of the pile in homogeneous hard rock is small, but more thrust is borne by the pile, and vice versa. (4) The theoretical value for a single anchored pile calculated by the optimized method is close to the measured value. These findings provide a scientific basis for landslide control projects in areas with weak-hard interbedded bedrock.
Applications of deep learning in mineral discrimination: a case study of quartz, biotite and K-feldspar from granite
Wei Lou, Dexian zhang
 doi: 10.1007/s12583-022-1672-7
[Abstract](125) [PDF 5838KB](34)
Mineral recognition and discrimination play a significant role in geological study. Intelligent mineral discrimination based on deep learning has the advantages of automation, low cost, less time consuming and low error rate. In this manuscript, characteristics of quartz, biotite and K-feldspar from granite thin sections under cross-polarized light were studied for mineral images intelligent classification by Inception-v3 deep learning convolutional neural network (CNN), and transfer learning method. Dynamic images from multi-angles were employed to enhance the accuracy and reproducibility in the process of mineral discrimination. Test results show that the average discrimination accuracies of quartz, biotite and K-feldspar are 100.00%, 96.88% and 90.63%. Results of this study prove the feasibility and reliability of the application of convolution neural network in mineral images classification. This study could have a significant impact in explorations of complicated mineral intelligent discrimination using deep learning methods and it will provide a new perspective for the development of more professional and practical mineral intelligent discrimination tools.
Origin of burrow-associated dolomites and its reservoir implications: A case study from the Lower-Middle Ordovician carbonates of Tarim Basin (NW China)
Chuan Guo, Daizhao Chen, Yong Fu, Xiqiang Zhou, Cunge Liu
 doi: 10.1007/s12583-022-1673-6
[Abstract](89) [PDF 11140KB](41)
The Yingshan Formation of the Lower-Middle Ordovician in the Tarim Basin (NW China) was mainly deposited in a shallow platform, which was intensely bioturbated with burrows filled with both dolomites and calcites. This study aims to figure out the controls on the dolomitization of burrow infills and the effects on petroleum reservoir quality based on petrographic examination, fluid inclusion microthermometry, and isotopic (C-O-Sr) geochemical analyses. The differentiation of burrow-associated carbonates (dolomites and calcites) was likely controlled by the interactions of sea-level oscillations of variable orders and depositional environments. The burrow-associated dolomites (BADs) were precipitated in a relatively restricted (i.e., lagoon) depositional environment during the lowstand of long-term sea level. In contrast, the burrow-associated calcites (BACs) were formed in a water circulation-improved lagoonal environment during the transgression of long-term sea level. Isotopic geochemical data indicate that the BADs in the Yingshan Formation were formed from slightly saline (i.e., mesosaline to penesaline) seawater, whereas the BACs were precipitated from nearly normal seawater. In addition to the anoxic condition, the presence of marine-sourced organic matter and sulfate-reducing bacteria, and a sufficient supply of dolomitizing fluids enriched in magnesium ions (Mg2+) and their Mg2+ concentration may have played a critical role in the formation of BADs. In the more permeable and disturbed burrow sediments as a result of burrowing, penetrating fluids with higher salinities and higher Mg2+ concentration relative to seawater favored dolomite precipitation. The fluids with seawater-like Mg2+ concentration, however, would lead to calcite precipitation. The progressive dolomitization of these burrowed sediments could have propagated the dolomitizing fronts and extended into ambient limestones, leading to the development of extensive dolomites. This dolomitization process can improve the petrophysical properties (porosity and permeability) and the potential as hydrocarbon reservoirs during the emplacement of hydrocarbons from underlying source rocks of the Cambrian to Lower Ordovician.
U-Pb ages and europium anomalies of detrital zircons from sediments in the West Kunlun Orogenic Belt: implications for the Proto-Tethys Ocean evolution
Yinggang Zhang, Xizhu Yao, Jin Wang, Wenqing Pan, Yongquan Chen, Baoshou Zhang, Tao Yang
 doi: 10.1007/s12583-022-1671-8
[Abstract](319) [PDF 5722KB](49)
The ocean crust remnants of the Proto-Tethys were preserved as the Kudi ophiolites in the West Kunlun Orogenic Belt (WKOB), and its evolutionary history was mainly constructed by research on igneous or metamorphic rocks in the WKOB. Sedimentary rocks in the WKOB received little attention in the past; however, they could provide important constraints on the evolution of the oceanic lithosphere. Here, a series of shales and greywackes found in the Kudi area of WKOB were studied to constrain their depositional ages and explore their significance in the evolution of the Proto-Tethys oceanic crust. U-Pb dating and europium anomaly (Eu/Eu*) were analyzed for detrital zircons from greywackes interlayers, while bulk rare earth elements and yttrium (REY) of the shales were measured. Detrital zircons U-Pb ages yielded a maximum depositional age of 436 Ma for the greywackes and black shales, while the REY distribution patterns of the black shales are similar to those of the Tarim Ordovician Saergan shales. Accordingly, the studied WKOB black shales were deposited in the Proto-Tethys Ocean during the Late Ordovician-Early Silurian period. The maximum depositional age at 436 Ma may represent a minimum closure time of the Proto-Tethys Ocean, which is also supported by the absence of increases in Eu/Eu* values during the Late Ordovician-Early Silurian. Besides, our Eu/Eu* values in detrital zircons indicate diminished orogenesis during the Archean to Mesoproterozoic, subduction-related accretion at the margins of the supercontinent Rodinia during the Neoproterozoic.
Fe-Ti oxide mineralization in the XV intrusion, Bafq mining district, Central Iran: insights from mineralogy, mineral chemistry and S isotopic data
Sakine Amraei, Majid Ghasemi Siani, Mohammad Yazdi, Liang Qiu, Bertrand Moine, Minghua Ren
 doi: 10.1007/s12583-022-1675-4
[Abstract](159) [PDF 5984KB](15)
The mafic-ultramafic intrusion in the XV anomaly area, which contains magmatic Fe-Ti oxide-(P) ore, is located in the Bafq mining district in the Central Iran. It consists of cumulate and layered Fe-Ti-bearing gabbros and pyroxenites. The mineral assemblages include clinopyroxene, Fe-Ti oxides, plagioclase, amphibole, apatite and sulfides (pyrite and chalcopyrite). The Fe-Ti oxides mainly consist of magnetite-titanomagnetite and ilmenite, which occur as disseminated, intergrowth, lamellae (trellis and sandwich textures) and inclusions. Magnetite in the gabbroic rocks is from the near end-member of Fe3O4 (<1 wt. % TiO2) to titanomagnetite containing up to 8 wt. % TiO2 (about 3.73 to 26.84 % Ulvospinel (XUsp)). Magnetite in pyroxenite rocks is characterized with TiO2 range from 0.46 to 3.14 wt. % (XUsp varied from 1.76 to 10.46 %). The abundances of V2O3 range from 0.03 to 1.29 and 0.24 to 1.00 wt. % for gabbro and pyroxenite, respectively. XUsp contents of magnetite show insignificant correlations with Al2O3 and MgO. The average XIlm in the ilmenite of gabbro is 92 %, whereas it is 90.37 % in the pyroxenite rocks. The MgO and V2O3 contents show a slightly positive correlation with TiO2 in ilmenite. The composition of clinopyroxenes in gabbro and pyroxenite rocks fall in the diopside to augite field with Mg# ranging from 67 to 98 and 74 to 96, respectively. In both rock types, amphiboles are mainly pargasite and rarely actinolite. Plagioclase in pyroxenite rocks are clustered in the labradorite to andesine fields with a compositional ranges of An46-69 and in gabboic rocks fall in two fields with compositional ranges of albite with An0.65-5.95 and labradorite with An50-63. The δ 34S isotopic values cover a limited range from +3.15 ‰ to +4.10 ‰ V-CDT consistent with magmatic origin. Fe-Ti mineralization are formed in two stages, minor inclusions of Fe–Ti oxide minerals in the pyroxene and plagioclase crystallized in the early magmatic stage, whereas interstitial oxides formed by fractional crystallization processes that accumulated by gravitational settling in the later stage as intercumulus phase. Gravitational settling process is supported by the observation of decreasing the amount of Fe-Ti oxides from Fe-Ti oxide- rich pyroxenite to weak mineralized gabbro (base to top). The high contents of H2O, phosphorate and high initial Ti-Fe in parental magma are the crucial factors controlling the Fe-Ti oxides enrichment and mineralization.
monitoring multi-temporal changes of lakes on the tibetan plateau using multi-source remote sensing data from 1992 to 2019: a case study of lake zhari namco
juan wu, chang-qing ke, yu cai, zheng duan
 doi: 10.1007/s12583-022-1639-8
[Abstract](217) [PDF 7604KB](15)
lake level, area and volume are sensitive indicators of climate change. at present, many studies have focused on the interannual water balance of lakes, but lake level and area can change remarkably with seasons, especially for lakes with seasonal ice cover. zhari namco, a seasonal frozen lake, was selected as an example to investigate its seasonal water balance. multi-source altimetry and landsat data were used to obtain the seasonal lake level and area from 1992 to 2019, and seasonal lake volume variations were also estimated. the results indicated the average lake level, area and volume in autumn were the largest. the lake level, area, and volume experienced three turning points approximately in 2000, 2010, and 2016, and showed an overall increasing trend from 1992 to 2019, with slopes of 0.15 m/year, 2.17 km2/year, and 0.14 km3/year, respectively. the lake area expanded significantly in autumn, which was related to the abundant precipitation. delay time of land surface runoff, increased temperature, and evaporation may be the reason for the low lake level and volume in summer. the precipitation was the dominant factor of water balance, which explained 62.09%, 62.43%, and 62.10% of the variations in lake level, area, and volume, respectively.
stochastic modeling of folded structures in scarce data scenarios using transiogram with locally varying anisotropy
yabo zhao, weihua hua, guoxiong chen, liang dong, zhipeng liu, xiuguo liu
 doi: 10.1007/s12583-022-1646-9
[Abstract](171) [PDF 3963KB](8)
sampling is usually scarce in geological modeling, and hence, complex and continuous geological phenomena are difficult to simulate when anisotropy changes locally. the current study aimed to present a method for modeling folded structures using transiogram with locally varying anisotropy in scarce data scenarios. based on the direction fields of locally varying anisotropy, a pathline-based algorithm was proposed to simulate the folds that are flattened and calculate the relative position of any two random points thereafter. compared to the traditional two-point spatial continuity measures (such as the variogram), the locally varying anisotropy transiogram could not only describe the high order markovian of the spatial distribution of geological bodies, but also do so with explicable physical implication. the report revealed that the locally varying anisotropy transiogram of horizontal strata can be directly obtained if the stratigraphic sequence and stratum thickness are known. in the case study, only one geological map was used in a real complex-fold area to successfully simulate the 3-d stratigraphic model.
gastropod fauna of the zuodeng permian-triassic boundary section in the nanpanjiang basin and its geometric-based morphological disparity analysis
xin sun, li tian, xincheng qiu, kaiping guan, erik tihelka, haijun song, jinnan tong, hao yang
 doi: 10.1007/s12583-022-1645-x
[Abstract](135) [PDF 4539KB](13)
gastropods, as one of the most common invertebrates in shallow marine environments, were heavily impacted by the permian-triassic mass extinction (ptme), with severe loss of diversity and remarkable dwarfism of body size. here, we report a new gastropod fauna from the permian‒triassic carbonates of zuodeng, guangxi province, south china. five species belonging to five genera and two indeterminate taxa are identified. the zuodeng fauna is dominated by paleozoic holdover taxa, including holopea teres, protostylus sp., and wannerispira shangganensis although most of them are found in the basal triassic microbialites. three gastropod communities have been recognized by cluster analysis. further morphological analyses show that the changing pattern of disparity, with diversity decreasing from community ⅱ to ⅲ, fits the interior-reduction model. in addition, the morphospace of community in microbialites is higher than those in non-microbialite bearing beds at zuodeng, shedding new light on the ecological role of microbialites during the permian-triassic environmental stress.
susceptibility mapping of ground collapse caused by anthropogenic activities
zhongmin mao, yuyong jiao, fei tan, xin qi, cong zeng
 doi: 10.1007/s12583-022-1644-y
[Abstract](113) [PDF 4967KB](3)
frequent ground collapses resulted by anthropogenic activities occur due to rapid urbanization. accurate susceptibility mapping is critical for disaster prevention and control. in this study, 1198 ground collapse cases were collected from 2017 to 2020 in shenzhen. after multicollinearity testing, eight effective factors (elevation, relief, clay proportion, average annual precipitation, distance from water, land use type, building density, and road density) were selected to construct an evaluation index system. ground collapse susceptibility was analyzed and mapped using the normalized frequency ratio (nfr), logistic regression (lr), and nfr-lr coupling models. finally, the rationality and performance of the three models were compared using the frequency ratio (fr) and receiver operating characteristic (roc) curve, respectively. all three models could effectively evaluate the ground collapse susceptibility (area under the roc curve (auc) > 0.7), though the result of nfr-lr model was more rational and had the highest performance (auc = 0.791) among the three models. shenzhen possessed ground collapses mainly in built-up areas, the greater the intensity of anthropogenic activity in a location, the higher the likelihood of a disaster. the high and very high susceptibility zones covered a total area of 546.76 km2 and involved the nanshan, luohu, and futian districts, as well as some areas of the baoan, guangming, and longgang districts.
Protoconodonts and Paraconodonts from the Machari Formation (upper Series 3 and Furongian) in the Eodungol Section, Yeongwol, Korea
Byung-su LEE
[Abstract](320) [PDF 2509KB](32)
The Machari Formation ranges from the “upper Series 3” (Middle Cambrian) to Furongian (Upper Cambrian) in the Yeongwol area, Korea. It has been known to yield relatively diverse invertebrate fossils. Particularly trilobite biozones of the formation have been well defined. On the other hand, little has hitherto been studied on conodont microfossils for the formation. This paper reports a diverse and well preserved protoconodonts and paraconodonts of Series 3 from the formation in the Eodungol section, exposed along a southern mountain trail of Mt. Sambangsan, Yeongwol, Korea. Five of the thirteen samples collected for conodont contain a rich protoconodont and paraconodont assemblage and numerous shelly fossils including trilobites, brachiopods, sponge spicules, hyolithids and incertae sedis. Sample Eo5 is extremely fossiliferous (465 elements, 96.5 % of total collection), and the most abundant species was Phakelodus elongatus (236 elements, 62 % of the Eo5 collection). The preservation is relatively good, but some specimens are corroded and fragmentary. Some of protoconodonts are exfoliated. Relatively larger ones were commonly preserved as phosphatized internal molds, particularly in specimens of Furnishina bigeminata, Furnishina leei n. sp., Muellerodus pomeranensis, Nogamiconus sinensis and westergaardodids. Phakelodids were commonly preserved as clusters. Among twenty species referable to nine genera, Furnishina bigeminata, Furnishina leei n. sp., Nogamiconus sinensis, Huayuanodontus tricornis, Proscandodus obliquus, and Westergaardodina grandidens were previously undescribed species in Korea. This assemblage is named herein as the Westergaardodina matsushitai Zone, which is new biozonal name replacing the old one i.e., Gapparodus bisulcatus-Westergaardodina matsushitai-Westergaardodina moessebergensis Assemblage. The W. matsushitai Zone corresponds to the Lejopyge armata trilobite Zone, and is well correlated with the upper Series 3 conodont biozones of the Westergaardodina matsushitai-Westergaardodina grandidens Zone of South China, and the Westergaardodina matsushitai Zone of North China, respectively. The present data allow a useful correlation to China and Baltica in relation to new subdivision of the Cambrian. Furnishina leei n. sp. is newly described.
Uranium Isotope Variations (234U/238U and 238U/235U) and Behavior of U-Pb Isotope System in the Vershinnoe SandstoneType Uranium Deposit, Vitim Uranium Ore District, Russia
V. N. Golubev, I. V. Chernyshev, B. T. Kochkin, N. N. Tarasov, G. V. Ochirova, A. V. Chugaev
[Abstract](31) [PDF 5507KB](19)
The U-Pb isotope system and uranium isotope composition (235U/238U and 234U/238U) were studied in a number of samples from the vertical section of the uranium ore body at the Vershinnoe sandstone-type deposit, Vitim uranium ore district, Russia. These parameters were determined to broadly vary. Deviations of the 234U/238U ratio from the equilibrium value indicate that the uranium ore was not completely conserved during the postore stage, and uranium was determined to continue mi‐grating at the deposit. Comparison of the U-Pb isotope age value and 234U/238U isotope ratio provides an insight into the migrate direction of uranium in the ore body. The broad variations (137.377–137.772) in the 238U/235U ratio over the vertical section of the ore body can be explained by the different settings of the samples relative to the ore deposition front and changes in the redox conditions when this front shifted. The fact that the δ238U and K234/238 values are correlated indicates that the transfer of the 234U iso‐tope into the aqueous phase may have been coupled with isotope fractionation in the 238U-235U system during the postformation uranium migration within the orebody.
Association of Sandstone-Type Uranium Mineralization in the Northern China with Tectonic Movements and Hydrocarbons
Yin Chen, Peisen Miao, Jianguo Li, Ruoshi Jin, Hualei Zhao, Lulu Chen, CongWang, Haoyu Yu, Xiaoru Zhang
[Abstract](77) [PDF 50719KB](27)
In the continental basins of Northern China (NC), a series of energy resources commonly co-exist in the same basin. As the three typical superimposed basins of different genesis in the NC, the Junggar, Ordos, and Songliao basins were chosen as the research objects. The favorable uraniumbearing structures are generally shown as a basin-margin slope or transition belt of uplifts with the de‐velopment of faults, which are conducive to a fluid circulation system. The Hercynian, Indosinian, and Yanshanian movements resulted in the development of uranium-rich intrusions which acted as the sig‐nificant uranium sources. The main hydrocarbon source rocks are developed in the Carboniferous, Permian, Jurassic and Cretaceous. The mature stage of source rocks is concentrated in the Jurassic–Cretaceous, followed by the multi-stage expulsion events. Influenced by the India-Eurasian collision and the subduction of the Pacific Plate, the tectonic transformation in the Late Yanshanian and Himala‐yan periods significantly influenced the sandstone-type uranium mineralization. The hydrocarbon reser‐voirs are spatially consistent with sandstone-type uranium deposits, while the hydrocarbon expulsionevents occur in sequence with sandstone-type uranium mineralization. In the periphery of the faults or the uplifts, both fluids met and formed uranium concentration. The regional tectonic movements moti‐vate the migration of hydrocarbon fluids and uranium mineralization, especially the Himalayan move‐ment.
An investigation of dislocation in olivine phenocrysts from the Hawaiian basalts
Zhuo-Yue Li, Da-Peng Wen, Yong-Feng Wang, Xiang-Wen Liu
 doi: 10.1007/s12583-020-1030-6
[Abstract](2073) [PDF 7048KB](159)
Intracrystalline distortions (like undulose extinction, dislocations, and subgrain boundaries) in olivine from naturally-deformed peridotites is generally taken as a sign of dislocation creep. However, similar features in olivine phenocrysts that were found in basaltic magmas are still not well understood. In particular, whether subgrain boundaries in olivine phenocrysts arise from plastic deformation or grain growth is still debated (In the latter case, they are essentially grain boundaries but not subgrain boundaries. Therefore, we used hereinafter subgrain-boundary-like structures instead of subgrain boundaries to name this kind of intracrystalline distortion). Here we carried out a detailed study on dislocations and subgrain-boundary-like (SG-like) structures in olivine phenocrysts from two Hawaiian basaltic lavas by means of petrographic microscopy, scanning electron microscopy, and transmission electron microscopy (TEM). Abundant and complex dislocation substructures (free dislocations, dislocation walls, and dislocation tangles) were observed in the decorated olivine grains, similar to those in olivine from peridotite xenoliths entrained by the Hawaiian basalts. The measured average dislocation density is 2.9 ± 1.3 × 1011 m-2, and is three to five orders of magnitude higher than that in laboratory-synthesized, undeformed olivine. TEM observations on samples cut across the SG-like structures by FIB (focused ion beam) demonstrated that this kind of structures is made of an array of dislocations. These observations clearly indicate that these structures are real subgrain boundaries rather than grain boundaries. These facts suggested that the observed high dislocation densities and subgrain boundaries were not resulted from crystal crystallization/growth, but were formed by plastic deformation. These deformation features do not prove that the olivine phenocrysts (and implicitly mantle xenoliths) were deformed after their capture by the basaltic magmas, but can be ascribed to a former deformation event in a dunitic cumulate, which was formed by magmatic fractionation, then plastically deformed, and finally disaggregated and captured by the basaltic magma that brought them to the surface.
Central Asia––A Global Model for the Formation of Epigenetic Deposits in a Platform Sedimentary Cover
Igor Pechenkin, Vladislav Petrov
[Abstract](11) [PDF 8469KB](7)
Metallogenic specialization of sedimentary cover in Central Asia is determined by its tec‐tonic setting that governs the hydrodynamic regime (exfiltrational or infiltrational) and as a consequence, the hydrogeochemical zonality (type of water and its gaseous and microcomponent composition). Hydro‐dynamic conditions (distribution of recharge and discharge areas) determine the direction of stratal water flow and location of mineralization resulted from the change in geochemical, thermodynamic, litholog‐ical, structural and other conditions. The exfiltrational regime suggests a dependence of the epigenetic mineralization upon the distribution and degree of preservation of hydrocarbon occurrences. Often, hy‐drocarbon matter serves as a reducing barrier and ore-concentrating factor during the formation of polymineral concentrations related to stratal oxidation zone. The supergene epigenetic ore-forming pro‐cesses are induced by the interaction between the Earth’s sedimentary cover and hydrosphere. Sedimen‐tary rocks themselves commonly serve as a source of ore materials. The ore deposition zones on geochemi‐cal barriers and ore material source are often located significantly apart from each other. The trend of these processes is determined by the position of ore-bearing depressions in large tectonic blocks.
Theoretical System of Sandstone-Type Uranium Deposits in Northern China
Ruoshi Jin, Huajian Liu, Xiaoguang Li
[Abstract](56) [PDF 19090KB](19)
Many theoretical results on sandstone-type uranium mineralization in northern China obtained by the uranium research team of the Tianjin Center of Geological Survey in recent years are presented. From the source sink system of uranium-producing basins, sedimentary environment of uranium-bearing rock series, ore-forming fluid information, evolution of tectonic events, basin forma‐tion and development, we redefine and classify uranium orebodies, redox zoning, and ore-controlling structural styles. We then systematically propose a theoretical system of sandstone-type uranium depos‐its in northern China. We conclude that sandstone-type uranium deposits in northern China are main‐ly found in sedimentary environments such as rivers, deltas, and alluvial fans in the Mesozoic and Cenozoic lowstand systems tract and in gray sandstone layers in the vertical redox zoning. The orebodies are controlled by the tectonic slope belt, which is in the shape of a strip on the plane, and spreads in a layer or plate on the section. Vertical (ups and downs) tectonic movement triggers large-scale phreatic flow in the basin, which is the real driving force for controlling the ore-forming fluid. The theoretical system of sandstone-type uranium deposits in northern China should be based on global tectonic move‐ment and environmental changes and take into account factors such as basins as a unit to study miner‐alization background, ore concentration areas as objects to study mineralization, and the correlation between regional tectonic movement and metallogenic process as a breakthrough point to study tecton‐ic events and metallogenic events. It should also be based on different basin types to establish metallo‐genic models. The innovative research results and ideas are summarized with the aim of promoting the continuous improvement of sandstone-type uranium mineralization theory in northern China.
U-Blacks Mineralization in Sandstone Uranium Deposits
Olga A. Doynikova
[Abstract](20) [PDF 18000KB](13)
Ores of infiltration sandstone-hosted uranium deposits in the sedimentary cover are ubiquitous composed of dispersed soot powder mineralization of black, brownish-black colour. Longterm studies of such loose U-ores by analytical transmission electron microscopy (ATEM) proved their polymineral nature. Uranium blacks are composed by at least three different U-mineral forms: oxide (uraninite), silicate (coffinite) and phosphate (ningyoite) which are present in various proportions of ore compositions. Such high dispersed friable uranium formations are difficult to diagnose by tradition‐al mineralogical methods (optical, XRD, IR and X-ray spectroscopy, etc.) which analyze total sample composition (phases mixture); their results characterize the dominant sample phase, omitting both sharply subordinate and X-ray amorphous phases. All research results are based on ATEM methods (SAED+EDS), which are optimal for crystallochemical diagnostics in the mineralogical study of such uranium ores. The article presents the diagnostic characteristics under electron microscope (EM) of uranous minerals from different sandstone deposits with their origin being discussed.
Classification of Sandstone-Related Uranium Deposits
Michel Cuney, Julien Mercadier, Christophe Bonnetti
[Abstract](109) [PDF 1583KB](26)
Sandstone type deposits are the most common type of uranium deposits in the world. A large variety of sub-types have been defined, based either on the morphology of the deposits (e.g., tabu‐lar, roll front, etc), or on the sedimentological setting (e.g., paleovalley, paleochannel, unconformity), or on tectonic or lithologic controls (e.g., tectonolithologic, mafic dykes/sills), or still on a variety of others characteristics (phreatic oxidation type, interlayer permeable type, multi-element stratabound infiltra‐tional, solution front limb deposit, humate type, etc.), reflecting the diversity of the characteristics of these deposits, but making it difficult to have a clear overview of these deposits. Moreover, uranium de‐posits occurring in the same sedimentological setting (e.g., paleochannel), presenting similar morpholo‐gies (e.g., tabular), may result from different genetic mechanisms and thus can be misleading for explora‐tion strategies. The aim of the present paper is to propose a new view on sandstone-related uranium de-posits combining both genetic and descriptive criteria. The dual view is indeed of primordial importance because all the critical characteristics of each deposit type, not limited to the morphology/geometry of the ore bodies and their relationships with depositional environments of the sandstone, have to be taken into account to propose a comprehensive classification of uranium deposits. In this respect, several key ore-forming processes, like the physical-chemical characteristics of the mineralizing fluid, have to be used to integrate genetic aspects in the classification. Although a succession of concentration steps, potentially temporally-disconnected, are involved in the genesis of some uranium mineralization, the classification here proposed will focus on the main mechanisms responsible for the formation and/or the location of ore deposits. The objective of this paper is also to propose a robust and widely usable ter‐minology to define and categorize sandstone uranium deposits, considering the diversity of their origin and morphologies, and will be primarily based on the temperature of the mineralizing fluid considered as having played the critical role in the transportation of the uranium, starting from synsedimentary ura‐nium deposits to those related to higher temperature fluids.
2024, 35(3): .  
[Abstract](1) [PDF 62836KB](0)
2024, 35(3): .  
[Abstract](1) [PDF 214KB](0)
Geobiology and Energy Science
Taphonomy and Paleoecology of Lycoptera: A Case Study from the Lower Jehol Group in Western Liaoning, Northeastern China
Zhongwu Lan, Rong Cao, Shujing Zhang
2024, 35(3): 737-746.   doi: 10.1007/s12583-023-1922-1
[Abstract](3) [FullText HTML](3) [PDF 22086KB](0)

Taphonomy and paleoecology (biological behavior) of the Early Cretaceous fish fossils are poorly described. This study reports for the first time a detailed taphonomical and paleoecological study on Lycoptera in the Mesozoic strata of western Liaoning Province, NE China. The XRD analysis shows that gismondine is the dominant clay minerals that could have contributed to the preservation of Lycoptera fossils and microbial mat fragments in the fossil-bearing horizon. Gismondine may have formed under volcanism-related hydrothermal regime that was transformed from crystal and lithic fragments. The μ-XRF imaging analysis shows a dominant chemical composition of Al, Si, P, S, Rh, K, Ca, Ti, C, Cr, Mn, Fe, Ni, among which P, Ca, C and S are enriched in the fish skeleton in comparison to the matrix. This suggests a dominant apatite composition for the fish skeleton. Hydrothermal influence did not smear off these organic signals probably because of protection of gismondine. The coexistance of C and S with Ni is assumed to represent recovered primary productivity following volcanic explosions and toxic gas emissions. The head of juvenile fish stays close to the body of adult fish. Pending further discoveries, such phenomenon is interpreted to suggest that adult fish actively protected juvenile fish in the presence of environmental pressures such as anoxia and deterioration of water quality induced by volcanism. Ocean acidification and hypoxia in association with volcanism created a harmful environment causing mass extinction of fish. The adult Lycoptera protected their juveniles by its body at the moment before death. Such biological behavior will be increasingly reported given the wide occurrence of Lycoptera in Mesozoic strata.

Kerogen Kinetic Distributions and Simulations Provide Insights into Petroleum Transformation Fraction (TF) Profiles of Organic-Rich Shales
David A. Wood
2024, 35(3): 747-757.   doi: 10.1007/s12583-024-1981-0
[Abstract](3) [FullText HTML](3) [PDF 1350KB](0)

Two hundred and fifty single first-order Arrhenius reactions are simulated to generate S2 pyrograms at three heating rates 25, 15, and 5 ℃·min-1. The activation energy (E) and pre-exponential factor (A) of the reactions simulated follow a long-established trend of those variable values displayed by shales and kerogens. The characteristics of the transformation fraction (TF) profiles (product generation window temperatures) of the simulated single reactions are compared to the TF profiles of recorded shale pyrograms generated by multiple reactions with different E-A values lying near the defined E-A trend. Important similarities and differences are observed between the TF profile values of the two datasets. The similarities support the spread of E-A values involved in shale pyrogram best fits. The differences are most likely explained by the complexity of the multiple kerogen first-order and second-order reactions contributing to the recorded shale pyrograms versus the simplicity and crispness of the single first-order reactions simulated. The results also justify the validity of using the previously described “variable E-A pyrogram-fitting method” of multi-heating-rate shale pyrograms enabling optimizers to choose multiple reactions from an unlimited range of E-A values. In contrast, further doubt is cast on the validity of the constant-A pyrogram-fitting method used by the Easy%Ro technique, in that a distribution of reactions with a single A value is unlikely to represent the complex variety of kerogen macerals observed in shale formations. TF profiles generated by the variable E-A pyrogram-fitting method lie close to the established E-A trend and are likely to provide more realistic TF generation window temperatures than TF profiles generated by the constant-A pyrogram-fitting method.

Stuctural Geology and Geophysics
Partitioning Anatolian Kinematics into Tectonic Escape and Slab Rollback Dominated Domains
Jiannan Meng, Timothy M. Kusky, Erdin Bozkurt, Hao Deng, Ozan Sinoplu
2024, 35(3): 758-768.   doi: 10.1007/s12583-023-1906-3
[Abstract](1) [FullText HTML](1) [PDF 10476KB](0)

Anatolia is the global archetype of tectonic escape, as witnessed by the devastating 2023 Kahramanmaraş Earthquake sequence, and the 2020 Samos Earthquake, which show different kinematics related to the framework of the escape tectonics. Global Positioning System (GPS) motions of the wedge-shaped plate differ regionally from northwestwards to southwestwards (from east to west). Anatolia was extruded westward from the Arabian-Eurasian collision along the North and East Anatolian fault systems, rotating counterclockwise into the oceanic free-faces of the Mediterranean and Aegean, with dramatic extension of western Anatolia in traditional interpretations. However, which is the dominant mechanism for this change in kinematics, extrusion related to the Arabia/Eurasia collision or rollback of the African slab beneath western Anatolia is still unclear. To assess the dominant driving mechanisms across Anatolia, we analyze recent GPS velocity datasets, and decomposed them into N-S and E-W components, revealing that westward motion is essentially constant across the whole plate and consistent with the slip rates of the North and East Anatolia fault zones, while southward components increase dramatically in the transition area between central and western Anatolia, where a slab tear is suggested. This phenomenon is related to different tectonic driving mechanisms. The Arabia-Eurasia collision drives the Anatolian Plate uniformly westwards while western Anatolia is progressively more affected by the southward retreating African subducting slab west of the Aegean/Cypriot slab tear, which significantly increases the southward component of the velocity field and causes the apparent curve of the whole modern velocity field. The 2020 and 2023 earthquake focal mechanisms also confirm that the northward colliding Arabian Plate forced Anatolia to the west, and the retreating African slab is pulling the upper plate of western Anatolian apart in extension. We propose that the Anatolian Plate is moving westwards as one plate with an additional component of extension in its west caused by the local driving mechanism, slab rollback (with the boundary above the slab tear around Isparta), rather than separate microplates or a near-pole spin of the entire Anatolian Plate, and the collision-related extrusion is the dominant mechanism of tectonic escape.

Microstructures, Fabrics, and Seismic Properties of Mylonitic Amphibolites: Implications for Strain Localization in a Thickening Anisotropic Middle Crust of the North China Craton
Siqi Liu, Bo Zhang, Jinjiang Zhang, Jian Zhang, Lei Guo, Tao Wang, Baoyou Hang, Xiaorong Li
2024, 35(3): 769-785.   doi: 10.1007/s12583-021-1480-5
[Abstract](2) [FullText HTML](2) [PDF 17203KB](0)

Strain localization processes in the continental crust generate faults and ductile shear zones over a broad range of scales affecting the long-term lithosphere deformation and the mechanical response of faults during the seismic cycle. Seismic anisotropy originated within the continental crust can be applied to deduce the kinematics and structures within orogens and is widely attributed to regionally aligned minerals, e.g., hornblende. However, naturally deformed rocks commonly show various structural layers (e.g., strain localization layers). It is necessary to reveal how both varying amphibole contents and fabrics in the structural layers of strain localization impact seismic property and its interpretations in terms of deformation. We present microstructures, petrofabrics, and calculate seismic properties of deformed amphibolite with the microstructures ranging from mylonite to ultramylonite. The transition from mylonite to ultramylonite is accompanied by a slight decrease of amphibole grain size, a disintegration of amphibole and plagioclase aggregates, and amphibole aspect ratio increase (from 1.68 to 2.23), concomitant with the precipitation of feldspar and/or quartz between amphibole grains. The intensities of amphibole crystallographic preferred orientations (CPOs) show a progressively increasing trend from mylonitic layers to homogeneous ultramylonitic layers, as indicated by the JAm index increasing from 1.9–4.0 for the mylonitic layers and 4.0–4.8 for the transition layer, to 5.1–6.9 for the ultramylonitic layers. The CPO patterns are nearly random for plagioclase and quartz. Polycrystalline amphibole aggregates in the amphibolitic mylonite deform by diffusion, mechanical rotation, and weak dislocation creep, and develop CPOs collectively. The polymineralic matrix (such as quartz and plagioclase) of the mylonite and the ultramylonite deform dominantly by dissolution-precipitation, combined with weak dislocation creep. The mean P and S wave velocities are estimated to be 6.3 and 3.5 km/s, respectively, for three layers of the mylonitic amphibolite. The respective maximum P and S anisotropies are 1.5%–6.4% and 1.8%–4.5% for the mylonite layers of the mylonitic amphibolite, and 6.0%–6.9% and 4.5%–5.0% for the transition layers; but for the ultramylonite layers, these values increase significantly to 8.0%–9.1% and 5.1%–6.0%, respectively. Furthermore, increasing strain (strain localization) generates significant variations in the geometry of the seismic anisotropy. This effect, coupled with the geographical orientations of structures in the Hengshan-Wutai-Fuping complex terrains, can generate substantial variations in the orientation and magnitude of seismic anisotropy for the continental crust as measured by the existing North China Geoscience Transect. Thickened amphibolitic layers by extensively folding or thrusting in the middle crust can explain the strong shear wave splitting and the tectonic boundary parallel fast shear wave polarization beneath the Hengshan-Wutai-Fuping complex terrains. Therefore, signals of seismic anisotropy varying with depth in the deforming continent crust need not deduce depth-varying kinematics or/and tectonic decoupling.

Detrital Zircon of Devonian Sandstones in Changning-Menglian Suture Zone, Yunnan, SW China: Implications for the Early Evolution of Paleo-Tethys
Zhengqin Gan, Qinglai Feng, Yuehua Wei, Guichun Liu, Xiaomei Nie, Tianyu Zhao
2024, 35(3): 786-796.   doi: 10.1007/s12583-021-1470-7
[Abstract](3) [FullText HTML](3) [PDF 12383KB](0)

The Changning-Menglian suture zone is a critical tectonic belt pivotal to the evolution of the Paleo-Tethys. The Wenquan Formation, characterized as turbidite deposited on the western side of the Changning-Menglian suture zone as well as the eastern edge of the Baoshan Block. Analysis of detrital zircons from the Wenquan Formation reveals two significant age peaks approximately at 440 and 980 Ma, with additional age populations around 600, 780, and 2 500 Ma. The major age peak at about 440 Ma is come from the andesitic-dominant volcanic arc within the Lancang Block and the western Simao Block, corroborated by the presence of andesite fragments in thin section studies. Meanwhile, the zircons that form the secondary age peak at ~980 Ma and other older age groups probably originate from the Baoshan Block. Deposited on the western side of the Paleo-Tethyan ophiolites, the Wenquan Formation received detrital materials from the continental margin on the opposite side. Thus, the main Paleo-Tethyan Ocean basin was not sufficiently broad enough to cut off the transference of detrital materials. It was a relatively narrow basin in the Early Devonian.

Depositional Responses to the Mongol-Okhotsk Ocean Closure in the Central Area of the Great Xing'an Range: Insights into Thrust Faults and Foreland Basins
Zheren Zhao, Shichao Li, Lingyu Zhang
2024, 35(3): 797-811.   doi: 10.1007/s12583-023-1934-x
[Abstract](2) [FullText HTML](2) [PDF 13098KB](0)

The Mongol-Okhotsk Ocean, which has been closing gradually from the west to the east beginning since the Late Paleozoic, was an important part of the Central Asian Orogenic Belt. It influenced the tectonic framework of Northeast Asia in the Mesozoic, especially the Late Mesozoic arc-basin system that is widely distributed in the Great Xing'an Range. However, the manner in which the Mongol-Okhotsk Ocean affected the sedimentary basin development remains poorly understood. To address this issue, we conducted U-Pb dating of detrital zircon deposited sedimentary basins of the central Great Xing'an Range. By examining the possible provenances of the detrital zircon and the structural controls of the basins, we found that a key sedimentary unit was deposited around Late Jurassic–Early Cretaceous. Its provenance was a felsic source in a back-arc setting of an active continental margin. The findings also suggest the existence of a unified geodynamic setting that affected the coeval development of basins in the northern Great Xing'an Range and the Yanshan fold-thrust belt along the northern margin of North China Craton. This research helps to better understand the complex tectonic processes which shaped the Northeast Asia during the Late Mesozoic.

Late Mesoproterozoic to Early Neoproterozoic Tectonic Evolution of the SW Yangtze Block, South China: Evidence from U-Pb Geochronology and Lu-Hf Isotopes of Detrital Zircons from Sedimentary Rocks
Peiwen Liu, Xiaozhong Ding, Yanxue Liu, Jibiao Zhang
2024, 35(3): 812-827.   doi: 10.1007/s12583-021-1563-3
[Abstract](0) [FullText HTML](0) [PDF 9824KB](0)

In situ zircon U-Pb geochronological and Lu-Hf isotope studies of detrital zircons from Late Mesoproterozoic to Early Neoproterozoic sedimentary units on the southwestern margin of the Yangtze Block have important implications for the tectonic evolution of the Yangtze Block. The Huili Group contains zircons whose ages are mainly Late Archean to Mesoproterozoic (2 650–2 450, 2 100– 1 800, and 1 350–1 150 Ma). The Dengxiangying Group has one major age population of 1 900–1 600 Ma, and two subordinate age populations of 1 350–1 100 and 2 300–2 000 Ma. Yanbian Group sedimentary rocks have a zircon age population mainly in the range of 970–850 Ma, contemporaneous with the ages of widespread arc-related magmatism in the western Yangtze Block. Combining these results with previous work, the Huili and Dengxiangying groups were most likely deposited during ca. 1 160 to 1 000 Ma in an intra-continental rift basin setting, while the Yanbian Group accumulated during > 920 to 782 Ma in a back-arc basin setting at the southwestern margin of the Yangtze Block. In addition, all these results further suggest a tectonic transition from a continental rift basin to a convergent environment at the southwestern margin of the Yangtze Block at 1 000–970 Ma.

Crust and Upper Mantle Density Structures beneath the Eastern Tianshan Region and Its Tectonic Implications
Yiming Liu, Chao Chen, Qing Liang, Zhengwang Hu
2024, 35(3): 828-838.   doi: 10.1007/s12583-021-1599-4
[Abstract](2) [FullText HTML](2) [PDF 29732KB](0)

The deformation mechanisms of the Tianshan orogenic belt (TOB) are one of the most important unresolved issues in the collision of the Indian and Eurasian plates. To better understand the lithospheric deformation of the eastern Tianshan orogenic belt, we combined the S-wave tomography and gravity data to develop a three-dimensional (3D) density model of the crust and upper mantle beneath the eastern Tianshan area. Results show that the crust of the eastern Tianshan is mainly characterized by positive density anomalies, revealing widespread subduction-related magmatism during the Paleozoic. We however have also observed extensive low-density anomalies beneath the eastern Tianshan at depths deeper than ~100 km, which is likely linked to a relatively hot mantle. The most fundamental differences of the lithosphere within the eastern Tianshan occur in the uppermost mantle. The uppermost mantle layers in the Bogda Shan and Harlik Shan are relatively dense. This is likely associated with an eclogite body in the uppermost mantle. The most significant negative anomaly of the uppermost mantle is however found in the Jueluotage tectonic belt and the central Tianshan Block and is possibly associated with depleted mantle material. We suggest that these differences related to compositional changes may control the strength of the lithospheric mantle and have affected the uplift of the northern and southern segments of the eastern Tianshan after the Permian.

Convex-up Style of Deformation within Grabens in Regions of Incomplete Crossing Conjugate Normal Faults: A Numerical Simulation Investigation and Case Study
Zheng Li, Kai Wang, Xiong Xiong, Bing Zhou
2024, 35(3): 839-849.   doi: 10.1007/s12583-022-1709-y
[Abstract](2) [FullText HTML](2) [PDF 2813KB](0)

Crossing conjugate normal faults (CCNFs) are extensively developed in many hydrocarbon-producing basins, generally existing in the form of incomplete CCNFs. Nevertheless, the effect of the non-conjugate zone of the CCNFs on the conjugate relay zone post late tectonic action has not been previously studied. We use 3D elastic-plastic modeling to investigate the influence of incomplete (i.e., partially intersecting) CCNFs on the pattern of deformation of strata in the intersection region. A series of model simulations were performed to examine the effects of horizontal tectonic extension, fault size, and fault depth on the deformation of conjugate relay zones of incomplete CCNFs. Our analyses yielded the following results. (1) The model of incomplete conjugation predicts a convex-up style of deformation in the conjugate graben region superimposed on overall subsidence under applied horizontal tectonic extension. (2) The degree of convex-up deformation of the conjugate graben depends on the influence of the non-conjugate zone on the conjugate relay zone, which varies with the amount of horizontal tectonic extension, fault size, and fault burial depth. (3) Our results indicate that incomplete CCNFs can form convex-up deformation, similar to that in the Nanpu Sag area and provide a sound understanding of hydrocarbon migration and accumulation.

Petrology, Geochemistry and Ore Deposits
Petrogenesis and Economic Potential of the Sangong Mafic-Ultramafic Intrusion in the Eastern Tianshan, Central Asian Orogenic Belt: Constraints from Mineral, Whole-Rock, and PGE Geochemistry
Guochao Zhou, Yuwang Wang, Jingbin Wang, Yu Shi, Hongjing Xie, Dedong Li, Yong Fu, Pan Wu
2024, 35(3): 850-865.   doi: 10.1007/s12583-022-1777-z
[Abstract](3) [FullText HTML](3) [PDF 9438KB](0)

The Sangong Cu-Ni sulfide mineralized mafic-ultramafic intrusion is located on the southern margin of the Bogeda-Harlik belt, eastern Tianshan, China. The intrusion is a well-differentiated complex and is comprised of leucogabbro, gabbro, olivine gabbro, Pl-bearing peridotite, and Pl-bearing pyroxenite. The Pl-bearing pyroxenite hosts both irregularly disseminated sulfide and round droplet sulfide. The intrusive rocks have a wide range of SiO2(42.1 wt.%–50.48 wt.%) and MgO (6.21 wt.%–22.11 wt.%), and are enriched in light rare earth elements (LREE), large-ion lithophile elements (LILE; e.g., Rb, Ba, Sr, and Pb), and palladium platinum group elements (PPGE) but depleted in high-field-strength elements (HFSE; e.g., Nb, Ta, and Ti) and iridium PGEs (IPGE). These geochemical characteristics indicate that the Sangong mafic-ultramafic intrusion was derived from high degree of partial melting of depleted mantle and interacted with subduction-related material. The low Pd/Ir (3.21–27.44) but high Ni/Cu (1.64–24.16) ratios, combined with the olivine crystals with low Fo (60.88–78.65) and Ni (54.99 ppm–1 688.87 ppm) concentrations suggest that the parental magma of the Sangong intrusion were likely high MgO basaltic in composition that experienced extensive evolution prior emplacement. The Ce/Pb ratios (5.8–13.6) and Nb/U ratios (11.6–30.3) of the intrusive rocks all range between MORB and crustal values, the Nb/Yb and Th/Yb values are close to the lower crust values, together with the low Se/S ratios [(17-100) × 10-6)] suggest that the magma experienced assimilation not only in mantle source but also in conduit, but the degree of crustal contamination is limited. The Cu/Pd ratios of the rocks range from 3.9 × 104to 10.8 × 104, and the Cu/Zr ratios of Pl-bearing pyroxenite in the Sangong intrusion are > 1, combined with the presence of sulfide droplets in the Pl-bearing pyroxenite, indicating the parental magma experienced sulfide saturation and the economical ore bodies may present in the depth of the intrusion. Furthermore, given the discovery of the Baixintan and Yueyawan deposits, we propose the Dananhu-Harlik belt as an essential prospecting target for Cu-Ni mineralization in North Xinjiang.

Geochemistry and Zircon U-Pb and Hf Isotopes of Early Devonian Hardawu Granites in the Eastern Segment of the Ultrahigh-Pressure Metamorphic Belt, Northern Qaidam Basin
Hua Li, Ming Wang, Jiqing Li, Haikui Tong, Jiaxiang Dong, Minggang Tian, Xiaolin Chen, Leguang Li, Ting Xie, Xiong Li, Yuying Che
2024, 35(3): 866-877.   doi: 10.1007/s12583-022-1791-1
[Abstract](3) [FullText HTML](3) [PDF 4599KB](0)

The Hardawu granites in the eastern segment of the ultrahigh-pressure metamorphic belt, the northern Qaidam Basin, were studied by whole-rock major and trace elements and in-situ zircon U-Pb geochronology and Hf isotopes to discuss the petrogenesis and tectonic evolution. Geochronological results show that the granites have a crystallization age of 401 ± 3 Ma, suggesting that they were formed in the Early Devonian. The granites have SiO2 contents of 75.32 wt.%–76.05 wt.%, total alkali contents of 8.23 wt.%–8.36 wt.%, and K2O/Na2O ratios of 1.62–1.91. They were rich in K2O, poor in TiO2, MnO, MgO, and P2O5, and have A/CNK values of 1.05–1.07, Rittmann index δ values of 2.05–2.14, and differentiation index (DI) values of 92.85–94.18. They are high potassium calc-alkaline, weak-peraluminum, and highly differentiated I-type granites. The granites also show enrichment of large ion lithophile elements (LILE) such as Rb, Ba, and Th, and depletion of high field strength elements (HFSE) such as Nb, Ta, and Ti. The total REE concentrations range from 169 ppm to 232 ppm, with enrichments of light rare earth elements and negative Eu anomalies (δEu = 0.39–0.55). The zircon εHf(t) values range from -0.65 to -2.29, and the two-stage model ages (tDM2) changed within a small range of 1.44 to 1.54 Ga, indicating that the magma of the Hardawu granites was originated from the partial melting of Mesoproterozoic lower crustal materials. Combined with previous studies, we suggest that the Hardawu granites were formed in the extensional tectonic setting after the collision between the Qaidam Block and the central and southern Qilian Block in the Early Devonian.

Cooling History of Mesozoic Magmatism and Implications for Large-Scale Gold Mineralization in the Jiaodong Peninsula, East China: Constraints from T-t Paths Determined by U-Pb Thermochronology of Zircon and Apatite
Guangyan Zhou, Mingchun Song, Long Li, Yan Luo, D. Graham Pearson, Jianbo Zhou, Zhengjiang Ding, Xuefeng Yu, Yingxin Song, Jie Li, Shiyong Li
2024, 35(3): 878-889.   doi: 10.1007/s12583-023-1832-4
[Abstract](3) [FullText HTML](3) [PDF 13060KB](0)

The Mesozoic intrusions of the Jiaodong Peninsula, eastern China, host giant gold deposits. Understanding the genesis of these deposits requires the determination of the source of the parental auriferous fluid and the timing of gold mineralization, which are strongly influenced by the cooling/uplift histories of the hosting intrusions. We performed an integrated U-Pb geochronology study on both zircon and apatite from four major magmatic episodes of the Jiaodong Peninsula. The zircon and apatite U-Pb ages are 156.9 ± 1.2 and 137.2 ± 2.4 Ma for the Linglong intrusion, 129.9 ± 1.0 and 125.0 ± 3.8 Ma for the Qujia intrusion, 119.5 ± 0.7 and 117.2 ± 1.8 Ma for the Liulinzhuang intrusion, 118.6 ± 1.0 and 111.6 ± 1.6 Ma for the Nansu intrusion, respectively. The coupled zircon and apatite data of these granitoids indicate a slow cooling rate (11.9 ℃/Ma) in the Late Jurassic, and rapid uplift and cooling (35.8–29.2 ℃/Ma) in the Early Cretaceous. The dramatically increased uplift and cooling period in the Early Cretaceous are contemporaneous with large-scale gold mineralization in the Jiaodong Peninsula. This implies that thermal upwelling of asthenosphere and related tectonic extension played an important role in gold remobilization and precipitation.

Timing and Tectonic Setting of the Gaoaobei Tungsten-Molybdenum Deposit in Nanling Range, South China
Jianfeng Li, Kemeng Ma, Youyue Lu, Jianming Fu, Shunbo Cheng, Yuan Li, Chuanbiao Li
2024, 35(3): 890-904.   doi: 10.1007/s12583-022-1773-3
[Abstract](3) [FullText HTML](3) [PDF 13085KB](0)

The Gaoaobei tungsten-molybdenum deposit is a newly discovered large-scale quartz-vein-type deposit in the Nanling metallogenic belt in South China. The ore bodies are hosted in the Indosinian granites and the Cambrian Xiangnan Group slates and are controlled by NWW-oriented faults, which are obviously different from the "five-story building" model in southern Jiangxi Province. The magmatic rocks in the study area are dominated by medium- to coarse-grained biotite monzogranite, with a few NW-oriented fine-grained granite dykes. The medium- to coarse-grained biotite monzogranite and fine-grained granite dykes have zircon U-Pb ages of 229.4 ± 1. 9 Ma (MSWD = 1.5) and 164.9 ± 3.3 Ma (MSWD = 0.75), respectively, corresponding to the Indosinian and Yanshanian magmatism. The monzogranites have higher contents of FeO, CaO, K2O, P2O5, and TiO2, while the granite dykes have slightly higher contents of SiO2, Al2O3, MnO, and Na2O. Their A/CNK values are 1.11–1.75 and 1.19–2.25, and the contents of CIPW normative corundum are 1.71%–6.66% and 2.41%–9.50%, suggesting both the monzogranites and granite dykes are S-type granite. The total amount of rare earth elements in the monzogranites (from 84.7 ppm to 129 ppm) is slightly lower than that in the granite dykes (from 128 ppm to 133 ppm). The Eu/Eu* values range from 0.12 to 0.30 in monzogranites and from 0.001 1 to 0.001 3 in granite dykes, indicating the fine-grained granites underwent more intense fractional crystallization. The monzogranite and granite dykes have high 87Sr/86Sri values of 0.716 9–0.719 3 and 0.728 25–0.728 80, low εNd(t) values ranging from -10.2 to -9.6 and from -11.5 to -11.4, and TDM2 ages of 1 835–1 785 and 1 957–1 946 Ma, respectively. These isotope data indicate their origin from the remelting of the Paleoproterozoic crustal materials. Combined with regional geology, it is concluded that the medium- to coarse-grained biotite monzogranite was formed in a post-collisional extensional environment. In addition, 40Ar-39Ar dating of the greisen type tungsten-molybdenum ore gave consistent plateau age of 164.0 ± 1.2 Ma, isochronal age of 162.0 ± 2.4 Ma and anti-isochronal age of 161.4 ± 1.8 Ma. Combined with the published molybdenite Re-Os age, the Gaoaobei tungsten-molybdenum deposit was formed at ~164 Ma, which is inferred to be genetically related to the contemporaneous fine-grained granite dykes (165 Ma). The deposit was likely formed during the large-scale magmatism and mineralization event in the early Yanshanian of the Nanling Range in an intra-continental extensional environment caused by the subduction of the paleo-Pacific plate. The late and small granite dykes within the large granite plutons thus require further attention during mineral prospecting in the regions.

Seismology and Geohazards
Seismogenic Structure of the 1605 Qiongshan M7$ \mathrm{½} $ Earthquake and Its Holocene Activity History in Northern Hainan Island, China: Evidence from Cross-Section Drilling and Shallow Seismic Profile
Chaoqun Wang, Liyun Jia, Daogong Hu, Shibiao Bai, Zhengwang Hu, Dongxia Sun, Xiaoxiao Yang, Lei Zhang, Xiumin Ma
2024, 35(3): 905-917.   doi: 10.1007/s12583-021-1585-x
[Abstract](4) [FullText HTML](4) [PDF 10501KB](0)

The 1605 M7$ \mathrm{½} $ Earthquake is the only earthquake in the history of China that has caused large-scale land subsidence into the sea, with the total area of land subsidence exceeding 100 km2. The disaster has led to the sinking of 72 villages. There is still no clear understanding of the source seismogenic fault of this earthquake. In this work, we conducted a detailed study of the middle segment of the Maniao-Puqian fault (MPF), which is the epicenter area, through geomorphological survey, data collection, shallow seismic exploration, cross-section drilling, and chronological dating. The results showed that the middle segment of the MPF zone is composed of three nearly parallel normal faults with a dextral strike-slip: "Macun-Luodou fault (F2-1), Haixiu-Dongyuan fault (F2-2), and Changliu-Zhuxihe fault (F2-3)". And F2-2 is composed of two secondary faults, namely F2-2′ and F2-2″, with a flower-shaped structure buried under the ground. It is distributed nearly east-west, dipping to the north and has experienced at least five stages of activities since the Miocene. The vertical activity rates of F2-2′ and F2-2″ are ~2.32 and ~2.5 mm/a, since the Holocene, respectively. There were eight cycles of transgression and regression since the Miocene. The fault activity resulted in the thickening of the Holocene strata with a slight dip to the south, on the hanging wall, showing V-shaped characteristics. The MPF is likely the source seismogenic fault of the M7$ \mathrm{½} $ earthquake that hit Qiongshan in 1605.

In-situ Horizontal Extrusion Test of Herbaceous Root-Soil with Different Root Types
Fangcui Liu, Shengwen Qi, Shenglin Qi, Xiaokun Hou, Yanrong Li, Guangming Luo, Lei Xue, Xueliang Wang, Juanjuan Sun, Songfeng Guo, Bowen Zheng
2024, 35(3): 918-928.   doi: 10.1007/s12583-022-1661-x
[Abstract](239) [FullText HTML](207) [PDF 9994KB](35)

The influence of different types of roots on the soil is complex and still remains unclear. Four in-situ extrusion tests were conducted on two types of root systems, namely fibrous and tap root system, for three plants, Eleusine indica, Potentilla anserine, and Artemisia argyi, according to the classification in Botany, and the thrust-displacement curves and failure patterns of different samples were analysed by comparison to fill the aforementioned gap. Results reveal that the roots can reduce the characteristics of soil brittleness and enhance its capability to resist large deformation, and different root types contribute different effects to the strain-hardening behavior of the root-soil mass. The contribution of the fibrous root system to strength is limited, whilst the tap root system substantially enhances strength and stiffness. Results of failure patterns show that fibrous and tap root systems affect soil solidification and surface cracking reduction. However, the effect of the tap root system depends on the composition of lateral and tap roots: long and rich lateral roots are effective for resisting the creation of cracks, but thick tap roots with few and thin lateral roots may lead to several surface cracks.

Upper-Bound Limit Analysis of the Multi-Layer Slope Stability and Failure Mode Based on Generalized Horizontal Slice Method
Huawei Zhang, Changdong Li, Wenqiang Chen, Ni Xie, Guihua Wang, Wenmin Yao, Xihui Jiang, Jingjing Long
2024, 35(3): 929-940.   doi: 10.1007/s12583-022-1626-0
[Abstract](3) [FullText HTML](3) [PDF 3824KB](0)

Multi-layer slopes are widely found in clay residue receiving fields. A generalized horizontal slice method (GHSM) for assessing the stability of multi-layer slopes that considers the energy dissipation between adjacent horizontal slices is presented. In view of the upper-bound limit analysis theory, the energy equation is derived and the ultimate failure mode is generated by comparing the sliding surface passing through the slope toe (mode A) with that below (mode B). In addition, the influence of the number of slices on the stability coefficients in the GHSM is studied and the stable value is obtained. Compared to the original method (Chen's method), the GHSM can acquire more precise results, which takes into account the energy dissipation in the inner sliding soil mass. Moreover, the GHSM, limit equilibrium method (LEM) and numerical simulation method (NSM) are applied to analyze the stability of a multi-layer slope with different slope angles and the results of the safety factor and failure mode are very close in each case. The ultimate failure modes are shown to be mode B when the slope angle is not more than 28°. It illustrates that the determination of the ultimate sliding surface requires comparison of multiple failure modes, not only mode A.

Insight into the Permeability and Microstructure Evolution Mechanism of the Sliding Zone Soil: A Case Study from the Huangtupo Landslide, Three Gorges Reservoir, China
Qianyun Wang, Huiming Tang, Pengju An, Kun Fang, Junrong Zhang, Minghao Miao, Qingwen Tan, Lei Huang, Shengming Hu
2024, 35(3): 941-954.   doi: 10.1007/s12583-023-1828-0
[Abstract](2) [FullText HTML](2) [PDF 13689KB](0)

A large number of laboratory investigations related to the permeability have been conducted on the sliding zones. Yet little attention has been paid to the particular sliding zones of the slide-prone Badong Formation. Here, we experimentally investigate the permeability nature and the mechanism of seepage in the viscous sliding zone of the Huangtupo Landslide. Saturated seepage tests have been performed first with consideration of six dry densities and thirteen hydraulic gradients, in conjunction with the mercury intrusion porosimetry test and scanning electron microscopy test for the microstructure analysis after seepage. The results show that seepage in the sliding zone soil does not follow Darcy's Law, since there is a threshold hydraulic gradient (i0) below which no flow is observed and a critical hydraulic gradient (icr) over which the hydraulic conductivity (K) tends to be stable. The percentage of bound water could be responsible for the occurrence ofi0 and icr. Furthermore, pore size distributions (PSD) less than 0.6 µm and between 10 and 90 µm exhibit positive and negative correlations with the i0, respectively, indicating that the i0 is related to the PSD. The mechanism accounting for this result is that pore water pressure forces fine clay particles into the surrounding large pores and converts arranged particles to discretely distributed ones, thereby weakening the connectivity of pores. The seepages in the sliding zones behave differently from that in the sliding mass and sliding bed in response to the permeability.

Numerical Analysis of Surcharge Effect on Stability and Interaction Mechanism of Slope-Pile-Footing System
Chao Xu, Lei Xue, Yuan Cui, Mengyang Zhai
2024, 35(3): 955-969.   doi: 10.1007/s12583-023-1866-7
[Abstract](2) [FullText HTML](2) [PDF 3872KB](0)

To investigate the stability and interaction mechanism of the slope-pile-footing system under surcharge effects, the finite difference method (FDM) was adopted to analyze the response laws of the stability of the reinforced slope, evolution of the critical slip surface, stress characteristic of retaining structures, deformation and failure modes of the slope foundation and building footing under surcharge parameters, including the surcharge intensity, the surcharge position, and the surcharge width. The results show that surcharge parameters significantly affect the stability and the deformation characteristics of the slope-pile-footing system. Specifically speaking, with the increasing surcharge intensity and the decreasing surcharge position and width, the deformation and failure mode of the system will gradually evolve in a direction that is harmful to its stability. The interaction mechanism of the slope-pile-footing system is further clarified as the load transfer of the building footing, the generation of the additional stress in the slope foundation, and the adjustment of pile bending moment due to the stress redistribution. Correspondingly, the safety of anti-slide piles will determine the stability of the slope foundation and building footing. These findings are expected to provide guidance for the comprehensive development and utilization of filled slopes after reinforcement.

3-D Tunnel Seismic Advance Prediction Method with Wide Illumination and High-Precision
Peng Guan, Cuifa Shao, Yuyong Jiao, Guohua Zhang, Junpeng Zou, Fei Tan
2024, 35(3): 970-979.   doi: 10.1007/s12583-021-1503-2
[Abstract](4) [FullText HTML](4) [PDF 5055KB](0)

Tunnel seismic advance prediction can effectively reduce the construction risk during tunnel excavation. Compared with the 2-D method, the 3-D method is more conducive to describing the spatial characteristics of the geological body by adding the seismic data in the vertical direction. However, some drawbacks still need improvement in the current 3-D tunnel seismic prediction method. (1) The geometry is complex, which is destructiveness, high cost, and time-consuming, and will delay the tunnel construction schedule. (2) Illumination of the anomalous body is insufficient, and the precision of migration imaging is low. (3) Shot points are far away from the tunnel face, the energy loss at the shot points is more serious. (4) The received signals at the tunnel wall have the surface wave with strong energy when the shot points are placed on the tunnel wall. (5) The geometry is not linear, so the directional filtering method cannot be used to extract the reflection wave. To overcome the drawbacks of the current prediction method, a new 3-D symmetrical tunnel seismic prediction method is proposed. Six geophones are installed on the tunnel wall, two on the left side, two on the right side, and two on the top side. Twenty-four shot points are placed on the tunnel face and near both sides of the tunnel wall, twelve shot points on the left side and twelve shot points on the right side. The shot points will move along with the forward excavation of the tunnel. The wavefield analysis, illumination statistics, and 3-D reverse time migration imaging are used to evaluate the proposed method. The result of modeled data indicates that the proposed 3-D geometry has some advantages: (1) the geometry is simple and the geophone installation time is short; (2) it has high illumination energy, wide illumination range, and can improve the prediction distance and imaging accuracy; (3) the proposed 3-D method can better estimate the velocity of surrounding rock and is more conducive to extracting the reflection wave with high resolution.

Development and Deformation Characteristics of Large Ancient Landslides in the Intensely Hazardous Xiongba-Sela Section of the Jinsha River, Eastern Tibetan Plateau, China
Yiqiu Yan, Changbao Guo, Yanan Zhang, Zhendong Qiu, Caihong Li, Xue Li
2024, 35(3): 980-997.   doi: 10.1007/s12583-023-1925-y
[Abstract](3) [FullText HTML](3) [PDF 44610KB](0)

The upstream Jinsha River, located in the eastern Tibetan Plateau, has been experiencing intense geological hazards characterized by a high density of ancient landslides, significant deformation and reactivation challenges. In this study, remote sensing interpretation, field investigations, and Small Baseline Subset Interferometric Synthetic Aperture Radar (SBAS-InSAR) technologies have been employed. Along a 17 km stretch of the Jinsha River, specifically in the Xiongba-Sela segment, 16 large-scale ancient landslides were identified, 9 of which are currently undergoing creeping deformation. Notably, the Sela and Xiongba ancient landslides exhibit significant deformation, with a maximum deformation rate of -192 mm/yr, indicating a high level of sliding activity. The volume of the Sela ancient landslide is estimated to be 1.8 × 108 to 4.5 × 108 m3, and characterized by extensive fissures and long-term creeping deformation. The SBAS-InSAR results revealed significant spatial variations in the deformation of the Sela ancient landslide, generally displaying two secondary zones of intense deformation, and landslide deformation exhibits nonlinear behavior with time. Between January 2016 and February 2022, Zone Ⅲ1 on the southwest side of the Sela ancient landslide, experienced a maximum cumulative deformation of -857 mm, with a maximum deformation rate of -108 mm/yr. Zone Ⅲ2, on the northeast side of the Sela ancient landslide, the maximum cumulative deformation was -456 mm, with a maximum deformation rate of -74 mm/yr; among these, the H2 and H4 secondary bodies on the south side of Ⅲ1 are in the accelerative deformation stage and at the Warn warning level. We propose that the large-scale flood and debris flow disasters triggered by the Baige landslide-dammed lake-dam broken disaster chain in Tibetan Plateau during October and November 2018 caused severe erosion at the foot of downstream slopes. This far-field triggering effect accelerated the creep of the downstream ancient landslides. Consequently, the deformation rate of Zone Ⅲ2 of the Sela ancient landslide increased by 6 to 8 times, exhibiting traction-type style reactivation. This heightened activity raises concerns about the potential for large-scale or overall reactivation of the landslide, posing a risk of damming the Jinsha River and initiating a dam-break disaster chain. Our research on the reactivation characteristics and mechanisms of large ancient landslides in high deep-cut valleys provides valuable guidance for geological hazard investigation and risk prevention.

Application of Synthetic Iron Oxyhydroxide with Influencing Factors for Removal of As(V) and As(III) from Groundwater
Shakeel Ahmed Talpur, Muhammad Yousuf Jat Baloch, Chunli Su, Javed Iqbal, Aziz Ahmed, Hafeez Ahmed Talpur
2024, 35(3): 998-1009.   doi: 10.1007/s12583-023-1862-y
[Abstract](516) [FullText HTML](533) [PDF 7796KB](31)

Synthesized iron oxyhydroxide was applied for the adsorptive removal of As(V) and As(III) from the aquas media. Additionally, this investigation highlighted the synergistic effect of calcium carbonate in conjunction with iron oxyhydroxide, resulting in enhanced removal efficiency. The experiment was conducted under various conditions: concentration, dosage, pH, agitation, and temperature. Material characterizations such as Brunauer Emmett Teller, X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy were implied to understand adsorption mechanisms. The Langmuir model revealed optimal concentrations for As(V) = 500 μg/L at pH-5 and As(III) = 200 μg/L at pH-7, resulting in 95% and 93% adsorption efficiencies, respectively. Maximum adsorption capacities "qmˮ were found to be 1 266.943 μg/g for As(V) and 1 080.241 μg/g for As(III). Freundlich model demonstrated favorable adsorption by indicating "n > 1ˮ such as As(V) = 2.542 and As(III) = 2.707; similarly, the speciation factor "RL < 1" for both species as As(V) = 0.1 and As(III) = 0.5, respectively. The kinetic study presented a pseudo-second-order model as best fitted, indicating throughout chemisorption processes for removing As(V) and As(III). Furthermore, incorporating calcium carbonate presented a significant leap in the removal efficiency, indicating As(V) from 95% to 98% and As(III) from 93% to 96%, respectively. Our findings offer profound motivation for developing effective and sustainable solutions to tackle arsenic contamination, underscoring the exceptional promise of iron oxyhydroxide in conjunction with calcium carbonate to achieve maximum removal efficiency.

Understanding Surface Water-Groundwater Conversion Relationship and Associated Hydrogeochemistry Evolution in the Upper Reaches of Luan River Basin, North China
Le Zhao, Chunli Su, Wenbo Liu, Xianjun Xie
2024, 35(3): 1010-1023.   doi: 10.1007/s12583-022-1629-x
[Abstract](2) [FullText HTML](2) [PDF 4572KB](0)

Luan River is the main water source in Beijing-Tianjin-Hebei region, northern China, where the groundwater system is vulnerable and pollution issue is serious. It is significant for regional groundwater resources protection to identify the hydrogeochemistry evolution and affecting factors along flow direction occurred in the upper reaches, especially the surface water-groundwater (SW-GW) conversion relationship. In this study, recharge, conversion and geochemistry evolution of SW and GW were elucidated based on physical-hydrochemical indicators and stable isotopes in 36 GW samples and 20 SW samples, which were collected in July 2019 and July 2020. The factor analysis was further utilized to determine the main factors responsible for regional hydrogeochemical evolution. Results indicate that GW recharged SW in plateau area, and SW and GW recharged each other in typical Alpine valley area. The hydrochemical types are HCO3-Ca·Mg and HCO3-Ca, and the hydrochemical evolution is dominated by weathering of silicate and carbonate minerals. The cation exchange adsorption has minor impact on groundwater hydrochemistry. The rise of SO42- and NO3- contents in groundwater is related to industrial and agricultural activities. The main controlling factors of SW hydrochemical components included recharge from groundwater, industrial and mining activities, explaining 90.04% of data variance. However, water-rock interaction, agricultural and domestic sewage are responsible for GW quality, accounting for 83.38%.

Geoscience Big Data
Paleontology Knowledge Graph for Data-Driven Discovery
Yiying Deng, Sicun Song, Junxuan Fan, Mao Luo, Le Yao, Shaochun Dong, Yukun Shi, Linna Zhang, Yue Wang, Haipeng Xu, Huiqing Xu, Yingying Zhao, Zhaohui Pan, Zhangshuai Hou, Xiaoming Li, Boheng Shen, Xinran Chen, Shuhan Zhang, Xuejin Wu, Lida Xing, Qingqing Liang, Enze Wang
2024, 35(3): 1024-1034.   doi: 10.1007/s12583-023-1943-9
[Abstract](4) [FullText HTML](4) [PDF 9731KB](0)

A knowledge graph (KG) is a knowledge base that integrates and represents data based on a graph-structured data model or topology. Geoscientists have made efforts to construct geoscience-related KGs to overcome semantic heterogeneity and facilitate knowledge representation, data integration, and text analysis. However, there is currently no comprehensive paleontology KG or data-driven discovery based on it. In this study, we constructed a two-layer model to represent the ordinal hierarchical structure of the paleontology KG following a top-down construction process. An ontology containing 19 365 concepts has been defined up to 2023. On this basis, we derived the synonymy list based on the paleontology KG and designed corresponding online functions in the OneStratigraphy database to showcase the use of the KG in paleontological research.

Low Resource Chinese Geological Text Named Entity Recognition Based on Prompt Learning
Hang He, Chao Ma, Shan Ye, Wenqiang Tang, Yuxuan Zhou, Zhen Yu, Jiaxin Yi, Li Hou, Mingcai Hou
2024, 35(3): 1035-1043.   doi: 10.1007/s12583-023-1944-8
[Abstract](2) [FullText HTML](2) [PDF 649KB](0)

Geological reports are a significant accomplishment for geologists involved in geological investigations and scientific research as they contain rich data and textual information. With the rapid development of science and technology, a large number of textual reports have accumulated in the field of geology. However, many non-hot topics and non-English speaking regions are neglected in mainstream geoscience databases for geological information mining, making it more challenging for some researchers to extract necessary information from these texts. Natural Language Processing (NLP) has obvious advantages in processing large amounts of textual data. The objective of this paper is to identify geological named entities from Chinese geological texts using NLP techniques. We propose the RoBERTa-Prompt-Tuning-NER method, which leverages the concept of Prompt Learning and requires only a small amount of annotated data to train superior models for recognizing geological named entities in low-resource dataset configurations. The RoBERTa layer captures context-based information and longer-distance dependencies through dynamic word vectors. Finally, we conducted experiments on the constructed Geological Named Entity Recognition (GNER) dataset. Our experimental results show that the proposed model achieves the highest F1 score of 80.64% among the four baseline algorithms, demonstrating the reliability and robustness of using the model for Named Entity Recognition of geological texts.

Towards Achieving Carbon Neutrality: The Role of Vegetation Restoration in Karst Regions of Southwest China
Yuemin Yue, Lu Wang, Xinbao Zhang, Kelin Wang
2024, 35(3): 1044-1048.   doi: 10.1007/s12583-024-2010-z
[Abstract](1) [FullText HTML](1) [PDF 733KB](0)
Decoding the Puzzle of Late Ediacaran Glaciation(s)
Bin Wen, Yanting Lin, Fuyun Shen, Junyuan Zhou
2024, 35(3): 1049-1052.   doi: 10.1007/s12583-024-2014-8
[Abstract](4) [FullText HTML](4) [PDF 1347KB](0)
Intra-Oceanic Subduction Termination and Reinitiation of the Eastern Neo-Tethys in Myanmar
Yi Chen, Qinghua Zhang, Lin Chen, Kaihui Shi, Kyaing Sein
2024, 35(3): 1053-1058.   doi: 10.1007/s12583-024-2009-5
[Abstract](3) [FullText HTML](3) [PDF 3111KB](0)
Dating Kimberlite Using Apatite U-Pb Geochronology: A Case Study from Diamond-Bearing Dikes in South China
Jiawei Zhang, Huan Wang, Defeng He, Yuhua Zhu, Kun Wang, Yuan Qiu
2024, 35(3): 1059-1062.   doi: 10.1007/s12583-024-2013-9
[Abstract](3) [FullText HTML](3) [PDF 1326KB](0)
Coupled Surface Process and Orographic Precipitation Model for the Landscape Evolution of the Himalayas
Yuqiang Li, Xiaoping Yuan
2024, 35(3): 1063-1068.   doi: 10.1007/s12583-024-2012-x
[Abstract](0) [FullText HTML](0) [PDF 2449KB](0)
Resonance Analysis in a High-Rise Building: Combined Translational and Rotational Measurements
Linpeng Qin, Yun Wang, Chang Chen, Yongxiang Wei, Chunqi Liao, Yi Zhang, Chao Wang, Wentao Wan, Quanyang Shao
2024, 35(3): 1069-1074.   doi: 10.1007/s12583-024-2011-y
[Abstract](3) [FullText HTML](3) [PDF 2000KB](0)
A New Discovery of Mineralization as Subseafloor Hydrothermal Replacement in the Duddar Super-Large SEDEX Lead-Zinc Deposit in Pakistan
Huishan Zhang, Yucai Song, Jianing Sun, Jun Hong, Yasir Shaheen Khalil, Yanguang Li, Haidi Zhang, Zhihua Wang
2024, 35(3): 1075-1078.   doi: 10.1007/s12583-024-2015-7
[Abstract](3) [FullText HTML](3) [PDF 5702KB](0)
Landslide Displacement Prediction Based on Time Series and PSO-BP Model in Three Georges Reservoir, China
Dexiang Gao, Kou Li, Yuncheng Cai, Tao Wen
2024, 35(3): 1079-1082.   doi: 10.1007/s12583-021-1575-z
[Abstract](1) [FullText HTML](1) [PDF 707KB](0)
Effect of Reclamation on the Groundwater-Lake Water Interaction in Chen Lake
Kun Lei, Teng Ma, Liuzhu Chen, Zhenxing Li, Yu Chen
2024, 35(3): 1083-1086.   doi: 10.1007/s12583-022-1652-y
[Abstract](156) [FullText HTML](144) [PDF 1135KB](32)

Vol 35, No 3 , 2024

ISSN 1674-487X

CN 42-1788/P

Editor in Chief: Yanxin Wang

Executive Editors in Chief: Zhong-Qiang Chen, Jiang Shaoyong

Associate Editor:

Shu Jiang,Changdong Li,Rui Ma 
Qiliang Sun,Timothy M. Kusky,Dun Wang 
Lunche Wang,Long Xiao,Xin-Fu Zhao
Keqing ZongRenguang Zuo ,Zongjun Yin

2022 Impact Factor 3.3