Advanced Search

Indexed by SCI、CA、РЖ、PA、CSA、ZR、etc .

2000 Vol. 11, No. 3

Display Method:
Development of Geological Science in China in the Twentieth Century
Hongzhen Wang, Yusheng Zhai, Zhendong You, Baoheng Shi, Weiran Yang, Guangrong Yang
2000, 11(3): 197-203.

In the present stage of accelerated development of science and technology at the turn of the century it may be deemed that the geological science in China is destined to prosper, as viewed from the increasing society needs, the scientific problems and the basic technological background provided by the society, the three basic elements for the development of science. Owing to the sagacity and foresight of the founders of geology in China, Chinese geological research had already won a world fame in 1920s to 1930s. From the 1950s to 1970s the geological science in China had undergone a rapid development. From the end of 1970s onwards the geological science in China had undergone an overall development. With the acceptance of the new concept of Earth System Science by the majority of geologists, all branches of geological studies will merge into a comprehensive and coordinate research and the geological science in China will be facing an entirely new stage of development in the 21st century.

Problems of Sequence Stratigraphy in China
Hongzhen Wang
2000, 11(3): 204-214.

A comprehensive study of outcrop sequence stratigraphy in China began in the early 1990s. The investigated strata range from Mesoproterozoic to Quaternary and the studied areas cover the three platforms and margins, the Southern Himalayas and the East China and South China seas. Problems of general concern in the sequence stratigraphy of China are discussed. These are: the hierarchy for sequence stratigraphy, the third-order Sequence and eustasy, the chronostratigraphic boundaries and GSSP, and the International Stratigraphic Chart and the sequence chronostratigraphy of China. The average time interval of Mesosequence (25-40 Ma) and of the Sequence (2-5 Ma) is suggested and the minor sequences below the Sequence are discussed. The time interval of the Sequence shows no evident decrease with time, but several epochs with remarkable short intervals occur in the Phanerozoic, which may represent a planetary behavior denoting the special development stages in earth' s evolution. Sea level change curves are given separately for the three platforms and the different regions. The Global Stratotype Section and Point (GSSP) concept and practice are discussed, and a comparison between the first appearance point of biozone and the first flooding surface in the Sequence is made for designation of the chronostratigraphic boundary. It is suggested that the chronostratigraphic boundaries might be set at the first flooding surface in the Sequence for easy recognition. The idea of sequence chronostratigraphy is recommended, and a comparison between the International Stratigraphic Chart and the sequence chronostratigraphy of China is made. The close relation between chronostratigraphy and sequence stratigraphy makes it possible for sequence stratigraphy to improve chronostratigraphic research. It is pointed out that multidisciplinary study in chronostratigraphy is necessary and should be promising and profitable.

Discussion on Nontraditional Mineral Resources
Pengda Zhao, Jianping Chen
2000, 11(3): 215-219.

In this paper, the authors introduce the concept of nontraditional mineral resources, and propose the major system of nontraditional mineral resources, including nontraditional resources, research methods, mining and mineral economics. Then the authors conclude that the research on nontraditional mineral resources is not only significant to satisfication the human needs in the 21st century, but also important to the development of the present geological theory.

Issues on China Regional Metallogeny
Yusheng Zhai, Jun Deng, Runmin Peng
2000, 11(3): 220-227.

According to geotectonic evolution and regional lithospheric features, the authors proposed six metallogenic domains in China: (1) Tianshan Xingmeng metallogenic domain, (2) Tarim North China metallogenic domain, (3) Qinling Qilian Kunlun metallogenic domain, (4) Yangtze metallogenic domain, (5) South China metallogenic domain and (6) Himalaya Sanjiang metallogenic domain. In this paper, the authors also discuss, on the bases of geotectonic background and metallogenic evolutionary history, some metallogenic features of China: (1) A large percentage of ore formation occurred in paleo continental margins, including continental marginal rift and continental marginal accretionary orogenic belt. The majority of main mineral deposits are discovered on continental margins. (2) Superimposition of mineralization, favored the building up of giant and large mineral deposits, but often made the mineral deposits more complex in composition (associated components), morphology and structure. (3) Mineralization of crust derived anatectic granite is intensive and especially concentrated in the South China metallogenic domain. Mineralizations, including W, Sn and REE, are the products of long and mature development of W Sn polymetal rich earth crust in the metamorphic basement of South China Caledonian fold belt. (4) Epithermal ore forming system is well developed in the southwest part of Yangtze continental block. Ore deposits of Hg, Sb, As, Au, Ag and U densely occur in sedimentary strata of the Late Paleozoic to Triassic. Ge, Tl, Te can also constitute independent ore deposits. (5) Ore formation caused by tectonic dynamic activities is distinctive. Small scale continental blocks of China display intensive activities, which played a widespread and diverse role in ore control. Junctions of faults, synchronous faults, shear zone structure and metamorphic core complex are main ore control structures. (6) The gold mineralization is complex and diversified. The greenstone type gold ores in China were emplaced in the Mesozoic Yanshanian epoch after repeated mineralization and enrichment. As a result, the co product gold constituted 32 % of the gold output of China. (7) The mineralization is characterized by multiple stages and heterogeneity. The metallogenic epoch of China almost covers all geological periods. The general trend, the increase in intensity with time, culminates in Mesozoic Cenozoic and so do the varieties of ores and types of mineral deposits. (8) Ore mineralization culminated on continental margin in the Mesozoic, especially in the Yanshanian orogeny of the east part of China, resulting in the diversity of ores and intensive mineralization. These metallogeny features of China can be generalized as "composite continental metallogenic system".

New Findings in High-Pressure and Ultrahigh-Pressure Metamorphic Belt of Tongbaishan-Dabieshan Regions, Central China
Zhendong You, Zengqiu Zhong, Shutian Suo, Zeming Zhang, Bize Wei
2000, 11(3): 228-233.

The Tongbai-Dabieshan high-pressure (HP) and ultrahigh-pressure (UHP) belt is sandwiched between the Yangtze and the Sinokorean cratons. It connects the Qinling orogenic belt in the west and links toward the east to the Sulu ultrahigh-pressure (UHP) belt. At present there is a consensus that the UHP metamorphic rocks are the products of the oblique collision between the Yangtze and Sinokorean cratons during the Triassic. However, there is still a lot of controversies about the formation and exhumation of the HP-and UHP-metamorphic belts. The present research work on the composition and the structural geometry and kinetics of the HP-and UHP-metamorphic belt has shown the following new results: (1) The overall structural geometry pattern of Dabieshan is similar to the metamorphic core complex developed in the western North America; (2) The discoveries of HP and UHP metamorphic rocks in the north of Dabieshan indicate that the significance of Shuihou-Wuhe fault should be re-evaluated; (3) A series of micro-structural evidence, including the newly-found retrograde granulite facies assemblages in the garnet pyroxenites, substantiate the extensional processes following the collision event; (4) The discovery of partial melting phenomena in the UHP-metamorphic belts illuminates the relationship between the HP-and UHP metamorphic rocks and their associated granite gneiss. All of these new findings will greatly improve our understanding of the formation and exhumation of the high-pressure and ultrahigh pressure metamorphic belts.

Relic UHP Structures in Dabie-Sulu Region, China: Structural Expression and Geodynamic Significance
Shutian Suo, Zengqiu Zhong, Zhendong You, Hanwen Zhou
2000, 11(3): 234-240.

The present-day observed tectonic framework of ultrahigh pressure (UHP) metamorphic belt in the Dabie-Sulu region was dominantly formed by an extensional process at 200-170 Ma, under amphibolite facies conditions, following the Triassic collision between the Sino-Korean and Yangtze cratons. UHP relic structures, including massive eclogites with a weak foliation, UHP shear zones and A-type folds, that are preserved in less retrograde metamorphism and deformation overprinted eclogite lenses can be recognized using the tectonic analysis. Examples are drawn from the Chengmagang area and Hejiawan area, Hubei; Bixiling area, Anhui, and Donghai area, northern Jiangsu. A speculative kinematic model is proposed for the collision between the cratons based on the UHP relic structures studied, in combination with the data of petrography, geochronology and P-T path of UHP metamorphic rocks in the studied region which were reported in literature. It is stressed that only the early UHP relic structures, particularly, regionally consistent foliation and stretching lineations, record and reflect the formation of the UHP metamorphic rocks, and the relative dynamic and kinematic process related to the Triassic NNE-directed oblique collision between the Sino-Korean and Yangtze cratons.

Triassic Sequence Stratigraphy and Sea-Level Changes in Qomolongma Area, Southern Tibet, China: From Epicontinental Sea to Rift Basin
Xiaoying Shi
2000, 11(3): 241-251.

The Triassic in the Qomolongma area, southern Tibet, was deposited under an extensional tectonic setting from the Pangea supercontinent to continental rifting. From the Induan to Rhaetian, 12 depositional sequences (3rd-order) have been recognized, which can be grouped into 5 sequence sets and in turn make up a well defined mesosequence (2nd-order). Among the recognized marine transgressions, those at 250 Ma, 239 Ma, 231 Ma and 223 Ma respectively are particularly of significance and can be correlated widely across continents. The study shows that in Triassic the Qomolongma area experienced a sedimentary evolution from epicontinental sea to rift basin with the turning point at ca 228 Ma. During the early and middle epochs, the area was under epeiric sea, with carbonate ramp to mixed shoal environments predominant. In the late Carnian, the strong extension initiated listric faulting, thus resulting in rapid basement subsidence and the onset of a rift basin. From the late Norian to Rhaetian, it manifested as a rapid basin filling process in the area. Coupled with long-term sea-level fall, the excessive terrigenous influx led to the shift of environment from deep-water prodelta to shore and finally to fluvial plain.

Rapid Climatic Change during Past 60 ka Recorded in NE Indian Ocean and Its Correspondence from South China Land
Fang Nianqiao, Xuefang Chen, Chaoyong Hu, Yong Yin, Xuan Ding, Shihong Zhang, Haogang Nie
2000, 11(3): 252-258.

According to the marine records from the Bay of Bengal, northeastern Indian Ocean, and the continental records from the South China, the authors make a detailed discussion in this paper about the correlation between them and their implication of rapid climatic change.The marine records show its good response to the high latitudes both for cold events and for warm ones while the continental records mainly mirror those cold Heinrich events corresponding to the North Atlantic but bear strongly a local color in reflecting warm events.The authors assume that the heat transmission style may cause the unbalanced coupling relationship.

Cenozoic Calcareous Nannofossil Biostratigraphy of Sediments from Lingfeng Well in East China Sea
Xin Su, Fadong Wu, Pin Zhou, Jinshui Liu
2000, 11(3): 259-263.

A biostratigraphic study of calcareous nannofossils of sediments from Lingfeng No.1 well in the East China Sea was carried out to provide more detailed nannofossil data and a stratigraphic correlation among offshore wells located in the East China Sea.14 Paleocene to Pleistocene calcareous nannofossil zones were recognized based on a detailed examination. According to these nannofossil data, the Paleocene/Eocene and Pliocene/Pleistocene boundaries, as well as the Miocene base were determined.Oligocene NP23 and Miocene NN1 zones are firstly recognized by this study. The existence of Miocene NN1 at this well suggests that the Miocene transgression began in the Early Miocene in this area. The records of NP23 indicate that the marine Oligocene sediments exist in the series of Lingfeng wells, but probably as very thin layers.

Middle Triassic Stratigraphy and Sedimentary Paleogeography of South China
Jinnan Tong, Zhili Liu
2000, 11(3): 264-270.

The Middle Triassic was the great turning period of South China from marine sedimentary basins to continental deposits or erosion. This paper summarizes the distribution and variation of the stratigraphic sequences, lithofacies and biotas in various Middle Triassic depositional basins of South China. The close relationship between the biotic paleoecology and the lithofacies as well as the sedimentary facies, thus the paleogeography, is demonstrated. The process of the transition from the depositional paleogeography and its relation to the tectonic settings is concluded.

Batch and Column Experiments on Fluoride Removal from Waters Using Modified Zeolite
Huaming Guo, Yanxin Wang
2000, 11(3): 271-274.

High fluoride groundwater occurs widely in China, presenting a quite serious environmental problem.Zeolite from Xinyang, China was tested as the fluoride-removing adsorbent.Batch and column experiments on fluoride removal using modified zeolites treated with hydrochloric acid, sodium hydroxide, sodium chloride and ferric chloride, respectively show that 0.1 mol/L HCl modified zeolite can be used as an adsorbent for fluoride, with an adsorption capacity of 173.16 mg/kg.

Effects of Poisonous and Harmful Elements Brought about by Coal Mining on Water Environment in Zibo Coal Mine, Shandong Province, China
Zhaoli Shen, Jianli Zhang, Jiangtao He, Zuoshen Zhong, Minggao Tang
2000, 11(3): 275-280.

Coal resources are very abundant in Zibo, Shandong Province, China. A lot of mining sewages are discharged during the coal mining. The mining sewage is characterized by highǑ (SO42-), hardness and totally dissolved solids (TDS). Mining sewage in the southern Zibo is acidic, where heavy metals and benzene are detected. The Xiaofu River is polluted when mining sewage flows into it, so that the Mengshan Reservoir is polluted by Xiaofu River. The groundwater is polluted in Zichuan by the leaking of the Xiaofu River. The polluted Xiaofu River is thus used to irrigate the farmland in Mashang-Mengshui zone. The irrigation water affects the quality of shallow groundwater. The laboratory soil column test shows that SO42-, Cl-, Ca2+ and Mg2+ can migrate through vadose soil, especially SO42- and Cl-. KEY WORDSa mining sewage, surface water pollution, groundwater pollution.

Shear Alteration, Mass Transfer and Gold Mineralization: An Example from Jiaodong Ore Deposit Concentrating Area, Shandong, China
Jun Deng, Yusheng Zhai, Jianping Wang, Liqiang Yang, Yun Fang, Zhongshi Shun
2000, 11(3): 281-287.

Taking the gold ore deposit concentrating area of Jiaodong area in Shandong, China for an example, based on geological analysis, and applying Gresenso equation, Grantos isocon diagram and Oohara microelement calculation method, a thorough study on shear alteration, mass transfer and gold mineralization was carried out. The authors also made mathematic simulation and geochemical analysis. The work reveals temporal spatial changing regularities of temperature field and velocity field of fluids, and also reveals fluid transport chemical reaction coupling metallogenic dynamics of the Jiaojia gold ore concentrating area. During shear alteration process of the Jiaodong gold ore concentrating area, all kinds of components transferred with different amounts, fluid rock ratio was rather high and volume strain was of dilation type. Fast flow of ore forming fluid favors the occurrence of mixed fluid. Shear fractured zones are places where there was strong transportation reaction coupling mineralization. Ore bodies were located in dilation space of shear structure where there was the greatest fluid flux. After the emplacement of the rock body, a convex heat field was formed around the rock body. It is one of the main metallogenic forces. The major reason for mineralization is the mobilization, migration and enrichment of ore forming elements induced by shear compressive extensional tectonism. Inclusion gold dominant low grade ores were formed in the early ore forming stage, while high grade ores, which contained fissure gold and polymetallic veinlets, were formed in late ore forming stage.

Post-Mesozoic Transformation of Tectonic Domain in Southeastern China and Its Geodynamic Mechanism
Ganguo Wu, Da Zhang, Bailin Chen, Jianshe Wu
2000, 11(3): 288-292.

Since the Mesozoic and Cenozoic, a transformation from a Tethyan Himalayan tectonic domain into a circum Pacific tectonic domain from Indosinian to Yanshanian is indicated in this paper, resulting in conspicuous changes in geophysics, tectono magmatic distribution, lithofacies and paleo geography, tectonic system in southeastern China. Tectonic analysis shows that the tectonic framework resulted from the compounding, transforming and superimposing of the two tectonic domains. The geodynamic mechanism of the transformation is mainly shown as the transverse and longitudinal heterogeneity of lithosphere, and the exchange between the crust and the mantle.

Engineering Strategies on Flood Control in Middle Reach of Yangtze River, China
Changoan Li, Hongfu Yin, Yufen Zhang, Yansheng Gu
2000, 11(3): 293-296.

Flood disaster has been a serious hidden danger since the ancient time. The essential cause for the fact that floods have not been eliminated for hundreds of years is that time honored strategies do not suit the cases of flood prevention. In the view of geological environmental analyses of flood formation and from the synthesis of experiences gained in flood control in the past hundreds of years, sluggish draining of flood, silt sedimentation in channel and building levee blindly constitute the main cause of intractable flood for a long time in the middle reach of the Yangtze River. Draining away silt and water is the only way to stamping out flood disaster. Opening up artificial waterways for flood diversion, draining away the silt of channel into the polders, and storing the flood water are important engineering measures for the flood control and damage reduction.

A New Accumulation Model of Coal Seams in France Extensional Basins
Wang Hua, Genfa Wang
2000, 11(3): 297-301.

This paper, based on the sedimentary features of the coal seams in the typical extensional (faulted) coal basins between two inland mountainous areas of the Central Massif (France) deals with the accumulation mechanism and the corresponding sedimentary-tectonic conditions of these thick coalbeds, and proposes a new coal accumulation model for the inland lacustrine-basin thick coalbeds. The presence of a great number of gravity-flow sediments such as detrital flow, diluted slurry flow or turbidity-current sediments in the coal seams, and that of the contemporaneous gravity slump and deformation structure in the coal seam itself both indicate that the lacustrine environment in the accumulation of the thick coalbeds was characterized by the relatively deep flood and violent sedimentation. This model can not only interpret reasonably the accumulation mechanism of the thick coalbeds developed in the fault basins in the Central Massif, France, but also show its features distinctively from those of the accumulation model of the traditional thick coalbeds.

Ore-forming Response to Syndepositional Submarine Volcanism in Langshan-Zhaertai Mesoproterozoic SEDEX Ore Belt, Inner Mongolia, China
Runmin Peng, Yusheng Zhai, Jun Deng, Rongge Xiao, Jianping Wang
2000, 11(3): 302-307.

Ore-forming process of the Dongshengmiao, Huogeqi, Tanyaokou and Jiashengpan deposits in Langshan-Zhaertai Mesoproterozoic SEDEX metallogenic belt is closely related to the syndepositional volcanic activities based on the following facts: (1) The Sm-Nd isochron age of the basic volcanic rocks varies from 1 491 Ma to 1 824 Ma (more than or close to the model age of the lead isotope of all sulfide minerals) in these deposits, withε(Nd, t)=(3.48-6.40)± 0.80, whose REE composition is enriched in LREE and depleted in HREE, indicating that these volcanic rocks were derived from the mantle or lower crust. (2) The REE composition of some Pb-Zn-Py-ores is also enriched in LREE and depleted in HREE. The chondrite-normalized REE patterns are similar to those of the basic-volcanic rocks. (3) In the lead isotope composition diagram of Doe and Zartman, most of sphalerite, galena, pyrite, pyrrhotite and chalcopyrite are plotted on both sides of the line for the mantle or between the lines for the mantle and lower crust. (4) Cobalt content of some pyrites is much higher than their nickel content (w(Co)/w(Ni)=11.91-12.19). (5) Some volcanic blocks and debrises have been picked out from some pyrite and pyrrhotite ores. (6) All Zn-Pb-Cu-Fe sulfide orebodies in these deposits occur in the strata overlying the metamorphic volcanic rocks in the only second ore-bearing formation. The Jiashengpan deposit lacks in syndepositional volcanic rocks in the host succession, only Pb and Zn occur without Cu, but the Dongshengmiao, Tanyaokou and Huogeqi deposits with syndepositonal volcanic rocks in the host succession contain Cu, indicating the relatively high ore-forming temperatures, besides Pb and Zn. The syndepositional volcanic eruption directly supplied some ore-forming metals and resulted in the secular geothermal anomaly favorable for the circulation of the submarine convective hydrothermal system, and in the precipitation of deep mineralizing fluids exhaling into the anoxide basins along the syndepositional fault system in the Langshan-Zhaertai rift.

Metallic Mineral Resources Assessment and Analysis System Design
Guangdao Hu, Jianguo Chen, Shouyu Chen
2000, 11(3): 308-311.

This paper presents the aim and the design structure of the metallic mineral resources assessment and analysis system. This system adopts an integrated technique of data warehouse composed of affairs-processing layer and analysis-application layer. The affairs-processing layer includes multiform databases (such as geological database, geophysical database, geochemical database), while the analysis application layer includes data warehouse, online analysis processing and data mining. This paper also presents in detail the data warehouse of the present system and the appropriate spatial analysis methods and models. Finally, this paper presents the prospect of the system.

Behavioral Diversity and Complexity Indicated by Metazoan Traces at a Topological Level since Proterozoic
Yiming Gong
2000, 11(3): 312-318.

On the basis of topological criteria, metazoan traces can be classified as four ichnoorders (clusters) and twenty-two ichnofamilies (kinds), which consist of nine basic and three combined topological configurations. At a topological level, the behavioral diversity and complexity indicated by metazoan traces have remained quite stable since the Early Cambrian. Dramatic changes of these traits took place in the Neoproterozoic, in which 75% (12/16) of the topoichnotaxa and all nine basic topological configurations of metazoan traces occurred, but the most complex and highest-level topological configuration occurred in the Early Cambrian of the coelomate animal explosive evolution, showing that in the Neoproterozoic and Early Cambrian gestated not only the Ediacarian fauna and all the basic types of multi-cellular animals known today, but also all the basic and the most complex metazoan traces through geological time.

High-Resolution Geochemical Significance of Lowest Triassic at Majiashan Section, Chaohu, Anhui Province, China
Yuanqiao Peng, Jinnan Tong, Guangrong Shi
2000, 11(3): 319-324.

The Permian Triassic boundary (PTB) and the lowest Triassic in the Yangtze region are considered to be the sediments of dysaeroxic and even anoxic environments, due to the dark thin-bedded fine deposits, the highly developed parallel beddings with pyrites, the suppression of bio-disturbance, and the monotonous fossils. However, the trace fossils there show a rather weak effect of the anoxic event. Meanwhile, the high-resolution geochemical data are analyzed with 2-cm interval in the PTB and the lowest Triassic at the Majiashan Section, Chaohu, Anhui Province. The results show that the water depth of Chaohu region in the earliest Triassic was shallow, which might be a feature of the neritic environment. The high-resolution geochemical proxies for anoxia have some contrary results. The geochemical data often indicate the dysaeroxic and even anoxic environments during that time, whereas other proxies (such as w(V)/w(Cr), w(Ni)/w(Co))denote that they are normal marine sediments.

Electrical Structure of Yarlung Zangbo Suture from Magnetotelluric Profiling of INDEPTH-MT
Handong Tan, Sheng Jin, Wenbo Wei, Leshou Chen, Ming Deng
2000, 11(3): 325-327.

The INDEPTH-MT results show that there are no electrical features of deep fractures along the Yarlung Zangbo River, but a large high-conductivity body exists in the area between Gyangze and Rinbung. It dips northward, extends downward up to the depth of about 55 km and indicates the exposure of the possible real position of the Yarlung Zangbo suture. There are three sets of electrical gradient and distorted zones reflecting the structure of faults in the high-conductivity region. These three fault belts, which dip northward and gradually converge downward to the main fault belt, and a series of south-dipping faults in the north side form the exhaled structural characteristics of the Yarlung Zangbo suture. There is a close relationship between the large high-conductivity body and the underground thermal state.

Discovery of Jinning Cycle Magmatism in Eastern Part of Eastern Kunlun Orogenic Belt and Its Significance
Yunhai Zhu, Yuanming Pan, Kexin Zhang
2000, 11(3): 328-333.

From the isotopic dating study of gneissic granodiorite, the authors discovered magmatism of the Jinning cycle. Intrusive rocks were formed in the Neoproterozoic, whose Pb-Pb ages range from (913±4) Ma to (1 011±4) Ma and U-Pb concordia age is (703±15) Ma. The tectonic settings of the rocks are volcanic arc or syn-collision. After the formation of the intrusive rocks, these rocks also experienced reconstruction of Caledonian metamorphism. Based on the Ar-Ar dating of metamorphic mineral of muscovite, the metamorphic time is determined to range from (386.8±0.8) Ma to (389.44±3.70) Ma.

Optimal Groundwater Development in Coastal Aquifers Near Beihai, China
Xun Zhou, Mingyou Chen, Li Wan, Juping Wang, Xuesheng Ning
2000, 11(3): 334-340.

Groundwater resources occur in a multi aquifer system in the alluvial coastal plain near Beihai, China. The aquifers receive recharge from precipitation, canal and reservoir infiltration, and discharge through subterranean drainage into the sea and through artificial pumping. A quasi three dimensional finite element model has been used to simulate the spatial and temporal distribution of groundwater levels in the aquifers. Various input parameters were considered in the simulation model. A linear optimization model has been developed for groundwater development within the coastal aquifers. The objective function of the model is to maximize the total groundwater pumpage from the confined aquifer. The control of sea water intrusion is examined by the restriction of the water levels at points along the coast and of the pumping rates in coastal management cells. The response matrix used in the optimization model was generated from the simulation model by forecasting drawdown produced by pumping at a unit impulse discharge. Groundwater development can be primarily optimized by the alteration of the pumping rates of the existing wells.

Charnockite Formation and Early Precambrian Crust Evolution in Yishui Area, Shandong Province, China
Shangguo Su, Xunruo Zhou, Deling Gu, Ling Hu
2000, 11(3): 341-345.

Charnockite and granulite in Yishui area, Shandong Province are located in the middle part of the Tancheng Lujiang fault zone, eastern China. Field studies have shown that the charnockites, derived from the adjacent granulites, are classified as three types: enderbite, garnet enderbite and hypersthene trondhjemite. In addition, two generations of minerals are present in the charnockites: the relic minerals such as garnet, hypersthene and clinopyroxene, and the neocrystallized minerals such as plagioclase and K feldspar. The relic minerals occurring in the granulite facies stage were affected by the later partial melting. The relic minerals, irregular and usually ragged in shape, occupy the interstitial positions in the neocrystalline minerals. The neocrystalline minerals are usually euhedral subhedral crystals. The study of petrology, mineralogy and geochemistry of charnokites concludes that the enderbite was formed by the anatexis of the two pyroxene plagioclase granulite, that the garnet enderbite was formed by the anatexis of sillimanite garnet gneiss, and that the hypersthene trondhjemite was formed by the anatexis of the leucocratic two pyroxene plagioclase granulite. The U Pb dating of the zircon indicates that the formation of the charnockite and granulite was related to the Archean Proterozoic upwelling of a mantle plume (hot spot) around 2 500 Ma, in Yishui area, Shandong Province.

Geothermal Characteristics and Geological Implications of Major Tectonic Units in China
Yang Wang, Jiyang Wang, Jinfu Deng
2000, 11(3): 346-351.

On the basis of more than 900 heat flow data in China and the surrounding seas, the authors study the geothermal characteristics of major tectonic units in China. The spatial pattern of heat flow and other thermal parameters for lithosphere exhibit significant lateral variation, originating from the Cenozoic tectonothermal activities related to the subduction of the Pacific plate and the collision between India and Asia. The mechanical strength of the crust and the seismicity of tectonic units were strongly affected by geothermal characteristics of units. The crustal heat production rate also shows the lateral heterogeneity, implying the significant lateral variation of bulk composition of the crust in China.

Microstructural Features of Garnets in Jadeite Quartzite from Dabie Mountains, China
Xiuling Wu, Tao Mou, Yujing Han, Douxing Li
2000, 11(3): 352-355.

Garnet is an important rock forming mineral of high pressure and ultrahigh pressure metamorphic rocks. Its popular isomorphism complicates its chemical composition and crystal structure. The selected area electron diffraction (SAED) and the high resolution electron microscopy (HREM) are used in this work to study the microstructures and ultrastructures of garnets in the jadeite quartzite from Dabie Mountains, China. The microstructures of the garnet occur mainly as free dislocations, dislocation walls, stacking faults, dislocation networks and sub grain boundaries. The dislocation density is ρ=n ×108/cm2 (n =1.7—7.5) and the deformation mechanism is the dislocation glide and dynamic recovery. The superstructures of the garnet crystal revealed by HREM occur mainly as dislocations, faults, domain structures and lattice deformations, indicating the strong stress during the formation of the jadeite quartzite.

Magnetic Structure of Continental Crust: Implications for Crustal Structure and Evolution
Qingsheng Liu, Shan Gao
2000, 11(3): 356-360.

Magnetic structure of the continental crust is one of the important geophysical aspects of continental lithosphere. This paper reviews the achievements in the research into the magnetic structure and its significance for crustal tectonics, composition, metamorphic facies, crust mantle interaction and magnetization of deep crust. Further studies are suggested according to the basic principles of rock and mineral magnetism in terms of petrology, geochemistry and structural geology. Emphasis is placed on new geological ideas and synthetic studies of the relationship between deep geological processes and interpretation of gravity, magnetic, electrical and seismic data. The relationships between magnetic, density, electricity, velocity, geothermal structures and deep geodynamic processes are taken as a system for the research into the deep geology.

Magnetostratigraphic Study of Meishan Permian-Triassic Section, Changxing, Zhejiang Province, China
Xiaohong Meng, Chaoshun Hu, Weimin Wang, Haiyin Liu
2000, 11(3): 361-365.

The authors present new paleomagnetic results obtained at the Meishan Permian Triassic (P/T) boundary section, Changxing County, Zhejiang Province. 330 samples in Changxing Group of Permian, 9 samples at P/T boundary, and 25 samples in Qinglong Group of Triassic are studied. Thermal and alternative filed demagnetization isolated a stable magnetization from most samples. This stable magnetization was thought to be acquired at or close to the time of formation of the rocks. The constructed polarity column shows that the bottom of the sampling section is forming a short reversed polarity. Above this short reversed polarity, there is a normal polarity, which lasts about 1.0 Ma. Below this short reversed polarity, are present 6 normal polarities and 7 reversed polarities between the upper Lower Changxing and Upper Changxing Group. Near the P/T boundary, the magnetization polarity transfers from reversal to normal, and the normal polarity may characterize the rest of the section. Susceptibility measurement of 550 samples shows a sharp change at the P/T boundary and a high correspondence with the minor frequency cycle of sedimentary. The spectrum of susceptibility indicates that there are 4 sedimentary cycles during 252-248 Ma in the section.

Field Test Results on Natural Field IP Method
Jin Yang, Handong Tan, Sheng Jin, Liangkui Fu
2000, 11(3): 366-368.

In this paper the authors propose the natural field induced polarization (IP) method and present the way to pick up IP effect. The relations between the object and anomaly are studied by taking field experiments as examples. The effectiveness and usability of the method are testified.

Dynamic Settings and Interactions between Basin Subsidence and Orogeny in Zhoukou Depression and Dabie Orogenic Belt
Jiazhen Sun, Xianghua Yang, Ronghua Qiu, Mingxi He
2000, 11(3): 369-371.

This paper presents a study of the geo-dynamic setting and the relation between orogenic uplift and basin subsidence in the inland Zhoukou depression and Dabie orogenic belt.Since the Mesozoic the evolution of Zhoukou depression can be divided into three stages: (1) foreland basin, (2) transitional stage, (3) fault depression.Formation and variations of basin were not only related to the orogenesis, but also consistent with the orogenic uplift.

Preparation and Characterization of Hydroxyiron-Montmorillonite Complexes
Libing Liao, Fuli Jia
2000, 11(3): 372-374.

Hydroxy Fe ions react slowly with montmorillonite by intercalation into their interlayer space and adsorption on their surface to form various hydroxyiron montmorillonite complexes. Hydroxyiron montmorillonite complexes are assumed to have the ability to adsorb anions such as H2PO4-, HPO42-, CrO42-, CrO2-, H2AsO4-, HAsO42-, AsO43- and F-, which may come from weathered rocks or waste industrial water, and result in concentration of P, Cr, As and F in soil. In this paper, hydroxy Fe ions including Fe(OH)2+, Fe(OH)2+ and Fe2(OH)22+ are prepared through hydrolysis of iron in acid solutions with different pH values. Corresponding hydroxyiron montmorillonite complexes are obtained by intercalation and adsorption of these hydroxy Fe ions into the interlayer space and on the surface of montmorillonite. The obtained hydroxyiron montmorillonite complexes are characterized with XRD and DTA, showing that they have similar basal space and thermal stability with Fe montmorillonite.