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On the siltation of the middle Yangtze River

Science china earth sciences 2004年第5期47卷 463-480页

作者： YIN Hongfu1, CHEN Guojin2, LI Chang抋n1 & WEI Yuan3.1. school of earth sciences,{3., Wuhan 43.074, china 2. Hydrogeological Team, Hubei Bureau of Geology and Mineral resources, Jingzhou 43.100, china 3. Geological Survey of Jiangxi Province, Nanchang 3.0201, china school of earth sciences China University of Geosciences Wuhan 430074 China Hydrogeological Team Hubei Bureau of Geol./Mineral Rsrc. Jingzhou 434100 China Geological Survey of Jiangxi Prov. Nanchang 330201 China

About 5.2×108 t/a of silts from the upper reach of the Yangtze River are transported through Yichang into the middle Yangtze River. The middle Yangtze itself and its tributaries yield ca. 0.8×108 t silts annually. Of this total 6×108 t/a input of silts, ca. 1.2×108 t/a are deposited within the river artery and lakes, while ca 4.83.108 t/a are at first transported into the lower reach through Datong, and then either deposited along the river and the Yangtze Delta, or output into the sea. Along the middle Yangtze River silting generally exceeds scouring, but the spatial and temporal distributions of scour-and-fill, as well as its distribution in the river valley transections, are uneven. Along the Yichang-Chenglingji and Jiujiang-Datong Segments of the middle Yangtze, scouring exceeds or equals silting. Silting mainly occurs along the Luoshan-Wuhan-Huangshi Segments with Wuhan as the pivotal point, as well as in the Dongting and Poyang Lakes. Even in these silting-dominated areas, there are times and parts of segments that scouring prevails. As to the transections, generally the river channel of main stream is scouring-dominated, forming V-shaped sections to a depth of 203. m or more, whereas the floodplains and bar islands are silting-dominated, forming wide and relatively high flats, which are often artificially transformed into protected embankments. Because the Jingjiang Levee separates the Jianghan Plain from Yangtze to the south, little has been deposited in that plain except a few sediments from the Han River—a tributary of the middle Yangtze. This factor plus the tectonic sag of that plain has made the altitude of plain surface several meters lower than that of the levee in most of the areas. Sil-tation along the Luoshan-Wuhan-Huangshi Segments has resulted in the elevation of flood level in this and upstream segments. River channel scouring plus floodplain silting have caused the transections of the middle Yangtze valley typically with deep channel and height

关键词： the middle Yangtze, scour-and-fill, siltation, silt utilization.

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*** Geological Relic Types and Functional Zoning Establishment

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地学前缘 2009年第S1期16卷 291-292页

作者： Sizuo Wang,Jianping Zhang,Chen Ni,Tingting Dong school of the earth sciences and {3.,china university of geosciences(Beijing),Beijing 100083.china.

Many of the beautiful geological features are formed by Jurrasic granites,such as granite picotgraphic stone, granite peak cluster,scouring ditches,miarolitic cavity, islands,beaches,sea caves and so *** are distinctive Shezu cultural relics and ancient architecttures preserved from Tang and Song *** a practical point of view that the development and protection of geoheritage need in accordance with the diversity of landforms and the uniqueness of culture,this

关键词： Mt.Taimushan functional zoning geoheritage conservation

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Multistage evolution of continental collision orogen:A case study for western Dabie orogen

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Chinese Science Bulletin 2009年第15期54卷 2568-2579页

作者： WU YuanBao State Key Laboratory of Geological Processes and Mineral resources, Faculty of earth sciences,{3., Wuhan 43.074, china State Key Laboratory of Continental Dynamics, Department of Geology, Northwest university, Xi’an 710069, china State Key Laboratory of Geological Processes and Mineral resources Faculty of Earth Sciences China University of Geosciences Wuhan China State Key Laboratory of Continental Dynamics Department of Geology Northwest University Xi’an China

The foramtion and evolution of collisional orogen is a prominent feature along convergent plate margins, and is generally a complex process. This article presents an integrated study of zircon genesis, U-Pb age and Lu-Hf isotope composition as well as geological characteristics for the western Dabie orogen to constrain its multi-stage evolution history. The results suggest that the formation of oceanic crust in the Huwan area was constrained at ca. 400―43. Ma, which was slightly later than the collision of the northern Qinling with the North china Block. It formed in a marginal basin in the northern margin of the Yangtze Block. The peak metamorphism of eclogite in the Huwan area occurred at ca. 3.0 Ma, and the timing of the initial exhumation of oceanic eclogite was about 270 Ma. The high to ultrahigh pressure (HP-UHP) metamorphic rocks in the Xinxian and the Hong'an metamorphic zones have the same ages and natures as those of the HP-UHP metamorphic rocks in the other Dabie-Sulu terrains, and also have experienced multi-stage exhumation, and thus can be taken as a coherent part of the Dabie-Sulu orogen. Therefore, the Qinling-Dabie-Sulu orogen is a typical multi-stage continental collision orogen, with an amalgamation process extending more than 200 Ma.

关键词：大别造山带大陆碰撞西部演变超高压变质岩碰撞造山带苏鲁造山带变质岩区

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The Construction of Natural Disaster Database of Alxa and Periodicity Analysis

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地学前缘 2009年第S1期16卷 300-301页

作者： Yan Zheng,Mingzhong Tian,Siwen Liu,Chao Ma school of the earth sciences and {3.,china university of geosciences(Beijing),Beijing 100083.china.

A compilation of all meaningful historical data of natural-disasters taken place in Alxa of inner-Mongolia is used here for the construction of a 65 Ma high precision *** data in the database are divided into subsets ... 详细信息

关键词： Alxa natural disaster databases periodicity

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Problems of Sequence Stratigraphy in china

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Journal of earth Science 2000年第3期19卷 10-20页

作者： Wang Hongzhen Faculty of earth sciences and Mineral resources,{3., Beijing 100083. china

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.

关键词： sequence stratigraphy chronostratigraphy GSSP china.

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External Influence to Geochemical Assessment of the Land Quality—Atmospheric Dry and Wet Deposition

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地学前缘 2009年第S1期16卷 305-306页

作者： Wei Wang,Zhongfang Yang,Qingye Hou,Rongjie Bai school of earth sciences and {3.,china university of geosciences(Beijing),Beijing 100083.china.

The heavy metals in the atmosphere mainly come from the gas and dust which involved by the energy costs,transport,metallurgy and building materials *** than the element of Hg,the heavy metals come into the atmosphere ... 详细信息

关键词： geochemical assessment atmospheric deposition deposition fluxes external influence

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"Three-Component" Digital Prospecting Method: A New Approach for Mineral resources Quantitative Prediction and Assessment

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Journal of earth Science 2004年第3期 6-13页

作者： Zhao Pengda Chioa university of geosciences, Wuhan 43.074, china Chen Jianping {3. of the earth sciences and resources, china university of geosciences, Beijing 100083. china Chen Jianguo Institute of Mathematical Geology, china university of geosciences, Wuhan 43.074, china Zhang Shouting {3. of the earth sciences and resources, china university of geosciences, Beijing 100083. china Chen Yongqing china Geological Survey, Beijing 100073. china

Three-component" method consists of three close-connected aspects: geological anomaly, diversity of mineralization and mineral deposit spectrum. All these three concepts are not new separately, but it is a new approach to combine these three aspects in one single concept for quantitative mineral resources prediction and assessment and it is also the first time to conduct a more detailed study in each aspect. Investigation and clarification of geological anomalies, diversity of mineralization and spectrum of mineral deposits are realized by digitization and quantification of ore forming controlling factors, ore-existing symbols or marks, characteristics of mineralization and regulation of ore-genesis and laws of distribution. These procedures lead to construction of a "digital model" for mineral resources prediction and assessment.

关键词： three-component" method geological anomaly diversity of mineralization spectrum of mineral deposits.

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Triassic Sequence Stratigraphy and Sea-Level Changes in Qomolongma Area, Southern Tibet, china: From Epicontinental Sea to Rift Basin

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Journal of earth Science 2000年第3期19卷 47-57页

作者： Shi Xiaoying Faculty of earth sciences and Land resources,{3., Beijing 100083. china

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 (3.d 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, 23. Ma, 23. 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.

关键词： Triassic sequence stratigraphy sea level change cycles basin evolution southern Tibet.

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Basic Lithofacies-Succession Model for the Wumishan Cyclothems: Their Markov Chain Analysis and Regularly Vertical Stacking Patterns in the Third-Order Sequences

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Acta Geologica Sinica(English Edition) 2001年第4期75卷 421-431页

作者： MEI Mingxiang, MA Yongsheng and GUO Qingyin Institute of earth sciences and Natural resources,{3., Beijing 100083.4} Petrochemical Corporation (SINOPEC), Beijing 100029 china Univ Geosci Inst Earth Sci & Nat Resources Beijing 100083 Peoples R China china Petrochem Corp SINOPEC Beijing 100029 Peoples R China

The Mesoproterozoic Wumishan Formation in the Jixian section of Tianjin is a succession of 3.00-m-thick carbonate strata formed in a period of about 100 Ma (13.0±20 Ma-12.7±10 Ma). In this succession of strata, the carbonate metre-scale cyclic sequences belonging to peritidal type with an approximately symmetrical lithofacies-succession are best developed. The wide development of 1:4 stacking patterns shows that these metre-scale cyclic sequences are genetically related to the short-eccentricity cycles, which are called the Wumishan cyclothems that could truly represent sedimentary cycles. Generally, massive and thick-bedded calcareous dolomites and dolomitic limestones of stromatolite biostromes and thrombolite bioherms constitute the central part of the Wumishan cyclothems. The lower and upper parts consist of tidal flat dolostones, sandy-muddy dolostone and the top part is composed of lagoonal facies dolomitic shales with a paleosol cap. Therefore, an approximately symmetrical lithofacies-succession is formed. Many features such as the clear deepening and shoaling vectors of cyclothems, and all kinds of marks of fresh-water diagenesis indicate that the Wumishan cyclothems are the product of autocyclic sedimentation governed by allocyclic high-frequency sea-level changes. The results of a Markov chain analysis reaffirm the existence of the lithofacies-succession model of the Wumishan cyclothems. The boundaries of the Wumishan cyclothems are marked by the instantaneous exposed punctuated surface, which leads to the discrepancy between the cyclothems and the parasequences of the sequence stratigraphy terminology system. It is difficult to form a judgment that the time span of the Milankovitch cycles in the Precambrian is certainly equal to that of the Phanerozoic, but the regularly vertical stacking patterns of the seventh-order rhythms, sixth-order cyclothems and fifth-order parasequence sets still indicate their consistency with the duration of the Milankovitch cy

关键词： Wumishan cyclothems Markov chain analysis Mesoproterozoic Jixian section Tianjin

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Geothermal and fluid flowing simulation of ore-forming antimony deposits in Xikuangshan

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Science china earth sciences 2006年第8期49卷 862-871页

作者： YANG Ruiyan1,2, MA Dongsheng2, BAO Zhengyu3. PAN Jiayong2, CAO Shuanglin2 & XIA Fei2 1. school of Mathematics and Physics, china university of geosciences, Wuhan 43.074, china 2. State Key Laboratory for Research of Mineral Deposits, Nanjing {3., Nanjing 210093. china 3. Faculty of earth sciences, china university of geosciences, Wuhan 43.074, china school of Mathematics and Physics China University of Geosciences Wuhan China State Key Laboratory for Research of Mineral Deposits Nanjing University Nanjing 210093 China Faculty of earth sciences China University of Geosciences Wuhan China

The Xikuangshan Antimony Deposit located in the Mid-Hunan Basin, china, is the larg- est antimony deposit in the world. Based on the hydrogeological and geochemical data collected from four sections, Xikuangshan-Dajienao (AO), Xikuangshan-Dashengshan (BO), Xikuang- shan-Longshan (CO) and Dafengshan (DO) in the Basin, an advanced metallogenic model related to deep-cyclic meteoric water of Xikuangshan Antimony Deposit is put forward in this paper using a model of heat-gravity-driving fluid flow transportation. The simulation results show that the ore-forming fluid of the deposit mainly comes from the Dashengshan and Longshan areas where BO and CO sections are located if the overall basin keeps a constant atmospheric precipitation and infiltration rate during mineralization, and that the average transportation speed of the ore-forming fluids is about 0.2―0.4 m/a.

关键词： ore-forming fluid, numerical simulation, geothermal field, geofluid transport, Xikuangshan, antimony deposits.

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