In this study, we investigated Early Paleozoic magmatic rocks of the Manlai Formation exposed along the eastern margin of the Lancang terrane to better understand the tectonic history of the Proto-Tethys. We present petrological, geochemical and whole-rock Sr-Nd and zircon Hf isotopic data for basalts and gabbros sampled from the Qianmai mélange. Zircon grains from six basaltic and gabbroic samples yielded U-Pb ages of 495–482 Ma. These rocks are characterized by tholeiitic and Nb-enriched compositions, with Nb/La ratios in the range of 0.38–1.38, similar to the typical Nb-enriched basalts. All the mafic rocks show slightly negative to positive ε_Nd(t) (-1.67 to+4.32) and zircon ε_Hf(t) values (-7.3 to +3.8). Elemental and isotopic data suggest that the Qianmai Nb-enriched mafic rocks were mainly derived from the mixing of an OIB-like source with a subduction-modified mantle wedge source. Together with magmatic and sedimentary records of similar ages in the Lancang terrane and the Baoshan Block, our results reveal Early Paleozoic magmatic and sedimentary sequences along an active margin of the Proto-Tethys. Taking into account the recently identified Early Paleozoic ophiolitic mélange in the Yunxian-Menghai belt, we consider the Qianmai magmatic rocks to represent the products of early-stage subduction-related magmatism within a primitive island arc or fore-arc setting associated with the southward subduction of the Proto-Tethys. We infer that prolonged south-dipping subduction on the northern margin of Gondwana persisted from the Cambrian to the Late Ordovician.

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. However, controversy exists about the Paleo-Pacific subduction's initiation time. This study uses detrital zircon U-Pb ages to discuss the Late Triassic source-to-sink system in the SESCB. It provides some references for the Paleo-Pacific subduction process based on crucial age information and zircons' trace elements. The paleogeography and similarity of detrital zircon age distribution indicate that three sinks were found 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 and 380–320 Ma, which might be sourced from the magmatic rocks formed by the Huinan Movement and Paleo-Pacific subduction. Note that 290–250 Ma zircons were widely distributed in the Upper Triassic strata, and their trace elements suggested the existence of a magmatic arc near the SESCB during the 290–250 Ma. Thus, we propose that the Paleo-Pacific subduction might have begun in the Early Permian.

The Luojiashan gabbro is a newly discovered mafic pluton emplaced in the Neoproterozoic Yingyangguan Formation in Yingyangguan region of northeastern Guangxi, South China. Comprehensive whole-rock geochemical and zircon geochronological and Hf isotopic analyses are performed on the gabbro and comparisons are made with the coeval mafic-ultramafic sills and dikes located in Longsheng region of northern Guangxi in order to understand the magmatic origin, evolution, and tectonic setting of the Luojiashan gabbro and to address the location of the suture zone of the Southwestern Jiangnan Orogen (SJO). LA-ICP-MS zircon U-Pb ages obtained from the Luojiashan gabbro show that it was emplaced at ~770 Ma. The gabbro contains abundant inherited zircons aged at 0.9–1.3 Ga, consistent with age spectrum of the Cathaysia Block. Chondrite-normalized REE pattern, primitive mantle-normalized trace element spider diagram, incompatible element ratios of Nb/Ta, Zr/Hf, La/Nb, Ba/Th, Th/La, and Ba/La, and Th/Yb-Ta/Yb discrimination diagram of the gabbro are indicative of OIB-like geochemical characteristics and of derivation from partially melted garnet peridotite of the asthenospheric mantle. Tectonic discrimination based on the trace and rare earth elements also indicate that the Luojiashan gabbro was emplaced in a within-plate extensional rift setting, probably as a result of Rodinia supercontinent dismantling, lithospheric thinning, and underplating and upwelling of the asthenospheric mantle. Based on zircon age, Hf isotopic data and comparison between northern and northeastern Guangxi, it is suggested that the Yingyangguan region was tectonically situated in a different tectonic locale from the Longsheng region of northern Guangxi at about 770 Ma during the post-orogenic mafic-ultramafic magmatic event, with the former within the Cathaysia Block and the latter along the southeast margin of Yangtze Block. The suture between the Yangtze and Cathaysia blocks must be located between Yingyangguan of northeastern Guangxi and Longsheng of northern Guangxi.

Identifying volcanic reservoir types and their distribution patterns in volcanic edifices is important for accurate prediction and exploration of hydrocarbon reservoirs. Herein, we analyzed the distribution patterns of different reservoir levels in volcanic edifices, discussed controlling factors, and reclassified reservoir types. This was done using core observations, whole-rock geochemistry, and reservoir physical property analysis, combined with logging, drilling, seismic, and oil-gas test data. Reservoirs can be divided into three classes based on their physical properties. The Mesozoic intermediate and basic rocks formed Class Ⅰ reservoirs, most lithologies formed Class Ⅱ reservoirs, and diabase intrusions and tight volcanic rocks formed Class Ⅲ reservoirs. Reservoirs form in different lithologies in the Huanghua depression due to weathering. Tectonic faults deepen the influence of weathering leading to the formation of reservoirs in tight. Additionally, volcanic rhythms and fractures control the vertical distribution of Cenozoic basaltic reservoirs. Volcanic reservoirs are classified into five types based on the main controlling factors and distribution patterns in volcanic edifices: tectonic-alteration, vesicle-fracture, weathered-effusive, weathered-eruptive, and weathered-tectonic types. Among these, the weathered-eruptive type can easily form Class Ⅰ reservoirs, making it the best target for exploration. Whereas the weathered-tectonic and vesicle-fracture types tend to develop Class Ⅱ reservoirs and can be potential targets. The new classification takes into account the relationship between reservoir levels and their distribution in volcanic edifices, it is more conducive to igneous reservoir prediction in the Huanghua depression. This study provides a novel idea for the classification and comparative study of igneous reservoirs in petroliferous basins.

The mudstone, gray tuffite and carbonaceous shale in the Upper Carboniferous Batamayineishan Formation (Bashan Formation) are essential source rocks for the volcanic reservoir in eastern Junggar, northwestern China. The kerogen components, vitrinite reflectance, Rock-Eval pyrolysis, lipid biomarkers and isotope compositions were measured to understand the provenance and depositional environment of Bashan Formation under the background of volcanic activities. There were 10 and 4 periods of volcanic eruptions identified in the wells CS and DZ, respectively. The source rocks developed in the late or intermittent phase of volcanic activity. The original island arcs of the Early Carboniferous evolved into the Wucaiwan sag and the Dishuiquan sag in the Bashan Formation. The Wucaiwan sag inherited the restricted, closed residual sea, which had a slightly anoxic and hypersaline environment. The Dishuiquan sag was generally an oxidizing lacustrine environment, influenced by a marine transgression that may have occurred at the end of the DZ_Ⅲ period during the Late Carboniferous. Although the total organic matter decreased due to the volcanic eruption, ash could cause an increase of aquatic organisms, coinciding with increases in salinity and reducibility in the Dishuiquan sag.

Migration pathways and distances of the oils in reservoir are thought to affect the distribution of pyrrolic compounds such as carbazole, its alkyl derivatives (alkylated carbazoles) and benzocarbazoles, although other factors, including maturity and depositional environments may also affect the distribution of these organic nitrogen compounds. In this study, 14 oil samples produced from conventional reservoirs in Pauls Valley, south Oklahoma were investigated using organic geochemical techniques. The sterane and hopane fingerprints suggest that most of the oils were sourced from the Devonian Woodford shale. Maturity parameters consistently indicate that the maturity level of the studied samples are all of similar maturity (Rc = ~0.7%), suggesting the distribution of the organic nitrogen organic compounds is possibly reflecting variations in relative migration distances. The distribution of alkylcarbazoles revealed a preferential enrichment during migration, with the nitrogen-shielded alkylcarbazole tending to be enriched relative to the nitrogen-semi-shielded alkylcarbozoles particularly in oils produced close to the Arbuckle uplift to the east. Correspondingly, another family of pyrrolic compounds, benzocarbazoles, whose distributions also indicated that the Pauls Valley Woodford oils came from deeper part of the Anadarko Basin as the benzo-[a]/([a]+[c])-carbazole ratios decrease eastwards. In more specific migration systems, although the pyrrolic compound indicators are potentially disturbed by the structural complexes, the general migration directions suggest that the studied oils in Pauls Valley Hunton uplift were sourced from the deep basin area, and migrate upwards in porous sediments due to the buoyancy. This study investigates the feasibility of using pyrrolic compounds to estimate relative migration distances and will aid in the interpretation of migration history by using the distribution of carbazole, alkylated carbazoles, benzocarbazoles isomers in the Anadarko and Ardmore Basin petroleum systems.

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 7 066.75 m in Well PBX1. In the Late Cretaceous, associated with volcanic activities and earthquakes, the caldera in the Well PBX1 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.

A sedimentological investigation was carried out to reconstruct the paleogeography of the Zagros Foreland Basin. Based on the study of more than 1 000 rock samples, nine carbonate microfacies and three terrigenous facies were identified. The study reveals that the Maastrichtian succession was deposited in a widespread homoclinal ramp in the High Zagros Basin. Three (Gandom Kar area), two (Ardal area), seven (Gardbishe area), five (Shirmard area), two (Kuh-e-Kamaneh area), three (Kuh-e-Balghar area), and six (Murak area) of depositional sequences (3rd order) were identified. The thickness of the lowstand systems tract (LST) due to activities of local faults and subsidence in the southeast is more than in the central and northwest of the High Zagros Basin during the Early and Early Middle Maastrichtian. During the Middle Maastrichtian, the shallow and deep marine deposits were formed during the transgressive systems tract (TST) and highstand systems tract (HST) in this basin and the rate of subsidence in the center of this basin (Gardbishe area) is higher than in other areas and the platform was drowned in this area. The falling relative sea-level due to activities of local faults led to that marine deposits were absent in all parts of the High Zagros Basin (except the south part) during the Late Maastrichtian. Paleogeographical studies on the Zagros Basin during the Late Campanian–Maastrichtian showed the following results: shallow marine environments were developed in the southeast of this basin, and the turbidite, delta, and fluvial environments in the northwest were developed more than in other areas.

Landslides pose a frequent geological threat, endangering both productivity and the well-being of human life and property. In recent years, landslides have received widespread attention in various fields. This article presents a comprehensive review of landslide research in the Qinling Mountains, China. The first part introduces landslide investigation and inventory, which include manual visual interpretation and automatic landslide extraction. The second part discusses the types, characteristics, and temporal-spatial distribution of landslides in the Qinling Mountains. In the third part, the mechanisms and stability analysis of landslides are explored, along with a discussion of the applicability of various simulation methods. The fourth part focuses on significant studies related to landslide evaluation, including susceptibility, hazard, and risk assessment. The fifth part addresses landslide monitoring and early warning systems. Finally, an assessment is made of the current issues and research status concerning landslide studies in the Qinling Mountains, followed by a discussion on future research directions.

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.

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.

In the early hours of June 24, 2017, a major landslide event occurred in Xinmo Village, Sichuan Province, China. The landslide instantly devastated the whole village. Ten people died and 73 were missing in this major landslide event. The study area has suffered from several strong earthquakes in the past 100 y. Present studies have reported that the cumulative damage effect of the Xinmo landslide induced by earthquake is obvious. In this study, we conducted a shaking table test based on the detailed geological survey, historical seismic data, satellite optical image, unmanned aerial vehicle photography. The test result presents the characteristics of multistage seismic damage and progressive deformation process of the Xinmo landslide model, and shows that the historical earthquakes have caused serious damage to the interior of rock mass in the source area. The test also shows that the cumulative damage of the model increases with an increase in duration of earthquake loading. When the excitation intensity increases to a certain value, the damage accumulation velocity of the model suddenly increases. It reveals that frequent historical earthquake loads can be regarded as a main reason for the damage and deterioration of landslide rock mass. Damage accumulation and superposition occur in the slope. Under a long-term gravity, deformation of the slope gradually increases until catastrophic failure is triggered. The progressive deformation process of slope is summarized. Firstly, under strong earthquakes loading, a tensile fracture surface forms at the rear edge of the wavy deformation high and steep bedding slope. It reaches a certain critical depth and expands along the interlayer structural plane. Meantime, damaged fissures perpendicular to the structural plane also appear in the steep-gentle turning area of the slope. Secondly, under a coupling action of seismic loading and gravity, the interlaminar tensile crack surface at the rear edge of the slope extends to depth continuously. Meanwhile, rock fracture occurs in the steep-gentle turning area. The "two-way damage propagation" mode of the interlayer tensile crack surface occurs until the sliding surface is connected. However, due to the "locking section" effect of rock mass at the slope foot, it can still maintain a short-term stability. Thirdly, under the influences of the heavy rainfall before a landslide and the long-term gravity of the upper sliding mass, rock mass in the steep section at the slope foot breaks outward. Finally, a catastrophic landslide occurs.

A debris flow, with terraced fields as the source area, broke out on June 25th, 2018 in the Xiaotuga area of Yunnan Province, China, and this kind of debris flow is rarely recorded. Two purposes in this study: (1) the influence of flow drag force on slope stability; (2) back-analyze the movement process of debris flow. First, the geological background and movement of this debris flow were described based on a field investigation. Then, drag force, calculated by the laminar flow theory, is added to the slope stability calculation model, which elaborates the initiation process of this disaster. Moreover, dynamic simulation software (DAN3D) was used to simulate the kinematic process of the debris flow with a variety of combination models. The study shows that the terrace area can quickly produce surface runoff and create a drag force under rainfall conditions, which is the essential reason for the initiation of debris flow. In addition, the use of the FVV (Frictional-Voellmy-Voellmy) model is found to provide the best performance in simulating this type of debris flow, which reveals that it lasts approximately 200 s and that the maximum velocity is 12 m/s.

The mechanical properties of bolts are important factors affecting the shear behavior of bolted joints. In this study, tensile and pure shear tests were conducted on five kinds of bolts made from different materials to measure their tensile and shear parameters. Direct shear tests were conducted to analyze the effects of tensile and shear strength parameters on the shear behavior of bolted joints. The test results showed that the mechanical properties of bolts made from different materials were clearly different and that these differences mainly affected the plastic deformation stage of the bolted joints. The larger the bolt elongation was, the larger the joint shear displacement at bolt failure. The tensile and shear strengths of the bolts were positively correlated with the shear strength of the bolted joints. According to the standard regression analysis, the bolt shear strength had a greater influence than the bolt tensile strength on the bolt contributions when the bolts were perpendicular to the joint surface. Based on the empirical equation for the bolt contribution proposed by Spang, the maximum shear loads in the pure shear test were introduced, and a new equation was established to predict the contributions of bolts. The prediction results obtained using the modified equation were in good agreement with the experimental results.

This study reveals the temporal and spatial evolution characteristics of the winter nighttime urban heat island (UHI) effect in the case of Beijing, China. The land surface temperature (LST) is retrieved by radiative transfer equation by using the remote sensing data from Landsat ETM+/OLI_TIRS from 2007 to 2017 for the winter nighttime period, and LST is then divided by the mean -standard deviation method into different levels of thermal landscapes. A combination of the migration calculation of gravity center and multi-directional profile analysis is used to study the directional differentiation characteristics of LST and the migratory characteristics of the gravity center of UHI. Finally, the overall temporal and spatial evolution characteristics of winter nighttime surface urban heat island (SUHI) in Beijing are studied, and the possible reasons for the changes are discussed. Results show that Beijing's UHI effect first increased and subsequently decreased from 2007 to 2017. The winter heat island in the urban area developed from low-density agglomeration to high-density agglomeration to low-density diffusion. Additionally, the high-level thermal landscapes migrated to the southwest along with the city center of gravity, and the expansion rate is fastest in the southwest, which is directly linked to the changes in the urban construction land. Moreover, the overall spatial distribution of winter nighttime LST is high in the east and south and low in the west and north, and is influenced by topography, land cover, urbanization, anthropogenic heat, and other factors as well.

Karapınar region (Konya, Türkiye) is one of the important regions of the world in terms of sinkhole formations. The research aimed to map the sinkholes in detail, to determine their spatial distribution and geometrical parameters. For this purpose, the long axes, short axes, depths and the proximity to settlements of the sinkholes were measured and their circumferences and areas were calculated. During the studies, the relationship of the sinkholes with lithology, their cross sections, shapes and the related structures were determined and the sinkholes were divided into five main groups as following: Basement rock sinkholes, Obruk Plateau sinkholes, Seyithacı sinkholes, Siyeklik sinkholes and Basin sinkholes. The d/l ratios of each sinkhole group were separately determined and interpreted. Accordingly, most of the d/l ratios are smaller than 0.2. Namely, the long axes are higher than the depth and it indicates that the shallow and wide sinkholes are common in the region. It has been determined that the fracture systems in the region, as well as the lithology and groundwater factors, are quite effective in the formation and distribution of the sinkholes in the Karapınar region. Considering the distance of the sinkholes to the settlements, Seyithacı sinkholes are the most risky group in the region because they are deep and close to the settlements.

Mangrove wetlands are among the four most productive tropical and subtropical ecosystems. They are also a core component of the coastal blue carbon ecosystem, which is of great ecological significance to human beings, plants, animals, and the global carbon balance. There has been a global decrease in the distribution of mangrove forests, and their ecological function has gradually degenerated since the Holocene. Sediment from coastal mangrove wetlands can provide records of climate change and human activities, and multiple proxies including palynology, leaf fossil, biomarkers, DNA, phytolith and stable isotopes, can be used to reconstruct the evolutionary stages of paleo-mangroves and to identify the effect of natural processes and human activities on the distribution and evolution of mangroves. This information can provide theoretical support for mangrove protection and for improving carbon sequestration capacity. This paper summarizes and compares the multiple proxies for mangrove reconstruction, reviews progress in the study of natural succession of global mangroves since the Holocene, expands on the influence mechanisms of human activities on mangrove growth and development and uses past information to lay a foundation for a model to predict future mangrove development.

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.

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 1 247 (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.

The mafic-ultramafic intrusion in the XV anomaly area, contains magmatic Fe-Ti oxides±(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 occurred 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 wt.% to 26.84 wt.% Ulvospinel (X_Usp)). Magnetite in pyroxenite rocks is characterized with TiO₂ range from 0.46 wt.% to 3.14 wt.% (X_Usp varied from 1.76 wt.% to 10.46 wt.%). The abundances of V₂O₃ range from 0.03 wt.% to 1.29 wt.% and 0.24 wt.% to 1.00 wt.% for gabbro and pyroxenite, respectively. X_Usp contents of magnetite show insignificant correlations with Al₂O₃ and MgO. The average X_Ilm 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 is clustered in the labradorite to andesine fields with a compositional ranges of An_46-69 and in gabboic rocks fall in two fields with compositional ranges of albite with An_0.65-5.95 and labradorite with An_50-63. The δ ³⁴S isotopic values cover a limited range from +3.15‰ to +4.10‰ V-CDT consistent with magmatic origin. Fe-Ti mineralization is 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.

The Zeit sand reservoir is one of the most prolific formations at Northwestern side of the Gulf of Suez. In this research we will try to coordinate between electrical, petrophysical properties, depositional environment and facies discrimination in order to evaluate the hydrocarbon potentiality of studied Zeit Formation. The statistical parameters for potassium (K), thorium (Th) and Th/U ratio contents have a general increase towards northwestern parts, whereas uranium (U) content has a general increase towards southeastern parts. The sandstone facies is distinguished from the other facies by its thorium content > 4 ppm. U has high carbonate content (U ≥ 1 ppm). Rocks' electrical properties vary greatly depending on a number of factors. Electrical measurements were taken at frequencies range of (5 × 10^-4 Hz–100 kHz) for fully saturated samples (clayey sandstone) with NaCl (20 gm/L). As salinity, clay content, and frequency increase, consequently does the electrical properties. The continental condition are present in northwestern part (back-sea) which is distinguished by high K percent, high Th, high Th/U ratio, and low U contents. Low K, Th, and Th/U ratio contents, with high U contents, characterize the marine depositional environment that existed around the east and southeastern parts (fore-sea coincide with the dipping of strata). Furthermore, the studied Zeit Formation has good petrophysical properties that coincide with marine conditions. The middle and eastern parts (around ISS-94 and CSS-288) is a good reservoir (porosity 36%–39%, shale content < 15%, hydrocarbon saturation 71%–92%, and net pay thickness 17–63 feet).

Most studies on solute transport in coastal aquifers affected by tides focus on the transport of instantaneous released solute, and there are few studies on continuously released solute affected by tides. In this study, the image monitoring method is used to establish the quantitative relationship between the concentration of the colored tracer and the hue value of the image, and the digital image is used to determine the tracer concentration distribution. Using image monitoring method laboratory experiments, quantitative analysis of the characteristics of continuously released solute transport in coastal unconfined aquifers under the tidal influence. Experiments show that the high tide inhibits the increase in the concentration of each point in the aquifer. Under the influence of tides, the solute plume retreats towards the land. During the low tide period, the solute plume migrates toward the sea again. And the solute plume will maintain a relatively stable shape after entering the aquifer for a long enough time. Ignoring the tidal effect seems to have little effect on the estimation of the position of the solute plume, but ignoring the tidal effect has a certain influence on the estimation of the dispersion range of the solute plume. No matter whether considering the tidal action, the final dispersion range of the solute plume is almost the same. But before the solute plume reaches a stable state, ignoring the tidal effect will lead to a smaller dispersion range of the solute plume.