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Seismic geomorphology of buried channel systems in the western South Huanghai Sea:retrodiction for paleo-environments

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Acta Oceanologica Sinica 2011年第1期30卷 47-58页

作者： KONG Xianghuai LIU Jian DU Yuansheng WEN Chun XU Gang faculty of earth {2. China University of Geosciences Wuhan 430074 China Qindao Institute of Marine Geology Ministry of Land and Resources Qingdao 266071 China Key Laboratory of Marine Hydrocarbon Resources and Environment Geology of Ministry ofLand and Resources Qingdao 266071 China College of Marine Geo-science Ocean University of China Qingdao 266100 China

Quantitative morphologic analysis of shallowly buried, dendritic channel systems in the continental shelf off the abandoned Huanghe River （Yellow River） mouth has been made based on interpretation of high resolution seismic profiles, with the attempt to estimate the paleo-hydrologic parameters when the incised-channels formed, then assess the paleoenvironment. The results indicate that the buried channel systems were formed about 44 cal ka BP when the shelf was subaerially exposed and subsequently drowned and filled during the Holocene transgression with the sea level rise continuously. The study area has experienced the processes from fluvial and estuarine to fully marine.

关键词： South Huanghai Sea (Yellow Sea) seismic geomorphology buried paleochannels,paleoenvironment

Characteristics of Bacillus cereus Spore Counts in Soils w ith Underlying Gold Mineralization in Northwestern Sichuan, china: Results from a Pilot Study

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Journal of china University of geosciences 2003年第1期14卷 8-15页

作者： Wang Hongmei Yang Fengqing Qiao Shengying faculty of earth {2.,{3. University of geosciences, Wuhan 430074 faculty of earth {2. China University of GeosciencesWuhan 430074

A pilot survey on a microbial mineral exploration method based on so il Bacillus cereus spore counts was carried out across three different gold mi ning regions, which vary in soil type, climate condition and geological setting in northwestern Sichuan, china. B horizon soils from these sites were analyzed for B. cereus spores, Au, Ag, Cu, Pb and Zn. The results show that the numbe rs of B. cereus spores generally increased in soils overlying gold mineraliz ation. Specifically, elevated spore counts were found in samples slightly offset from the outcrops of orebodies, whereas soils directly above the outcrops of or ebodies usually contained low spore counts. However, the background counts of B. cereus spores varied from place to place and were complicated by environmen tal and pedological factors, but the relative ratios of spore counts still were indicative of the underlying gold mineralization.

关键词： Bacillus cereus spores gold deposit soil china.

A High Precision Forecasting Model and Its Constructing Method for Vein Type Gold Deposits

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Journal of china University of geosciences 2001年第2期12卷 100-107页

作者： Zhang Jun faculty of earth Resources,{2. University of {3., Wuhan 430074 faculty of earth Resources China University of Geosciences

A high precision forecasting and prospecting model incorporating the “field theory field structure analysis field simulation”, a temporal and spatial structural framework reflecting local extremely fine structures, is established to make an effective extraction and an integrated analysis of multivariate forecasting information. This model can best show not only the coupling between metallogenic anomalous structure, mineralized structure and information structure, but also the extraction, optimization, matching and summarization of key forecasting information. The technological keys to this model are the fine structural analysis of geological and geophysical and geochemical anomalous fields and metallogenic fields, and the establishment of occurrence patterns for the spatial location of orebodies.

关键词： high precision forecasting model anomalous structure mineralized structure orebody location.

Relic UHP Structures in Dabie-Sulu Region, china: Structural Expression and Geodynamic Significance

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Journal of earth Science 2000年第3期19卷 40-46页

作者： Suo Shutian Zhong Zengqiu You Zhendong Zhou Hanwen faculty of earth {2.,{3. University of geosciences, Wuhan 430074,{3.

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 2.0-170 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.

关键词： UHP relic structure extensional process compressional regime stretching lineation Dabie Sulu region.

On Evolutionary Sequence Systematics: Taking Permian Waagenophylloid Coral Fauna as an Example

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Journal of earth Science 1999年第3期18卷 215-227页

作者： Xu Guirong Gong Shuyun Wang Yongbiao(faculty of earth {2.,{3. University of geosciences, Wuhan 430074) faculty of earth {2. China University of Geosciences Wuhan 430074

Evolutionary sequence systematics is a discipline in paleontology and biology that deals with phylogeny of organism, the main purpose of which is to understand relatives between species and taxa and to show their evolutionary sequence. The systematics is set up on the phenetic-cladistic systematics. A number of important theoretical concepts in the cladistics are added the concept of time in the systematics. For example, the time-span between the closest sister species is considered limited in the duration of their mother species. The foundational methodology of the systematics is to analyze sister-group and character mosaic distribution, and the key to study evolutionary sequence is to understand cbaracter mosaic distribution fully. These aualyses can be executed by using computer. In the paper, the Permian Waagenophylloid coral fauna is taken as an example to illustrate the analysis on evolutionary sequence. These coral fossils are widespread in Tethyan *** characters and a number of cbaracter states for each character used in study result from features of Waagenophylloid corals. According to principles of tbe widest distribution of character states, fossil records and ontogenesis we discerned plesiomorph character states for each character. Characters are divided into 4 ranks on the basis of their important place in pkylogeny. Based on the theory and methopology of tbe evolutionary sequence systematics the paper analyzes the sister groups and evolutionary sequence. In the examination each other between the analyses of sister groups and evolutionary sequence tbe paper found many importunt phenomena of paleontology,such as character degeneration, parallel evolution, and polydirectional clades, and distinguished a number of abnormal order. Iu the discussion to test tke rirst occurrence event8 of biostratigraphy we infer the Possible stratigraphic levels of some fossils.

关键词： evolutionary sequence systematics character mosaic distribution Permian Waagenophylloid corals

Ladinian radiolarian fauna, siliceous rock from the Xianshuihe Belt, West Sichuan and their tectonic significance

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Science china earth {2. 2005年第1期48卷 42-47页

作者： LIANG Bin, FENG Qinglai, WANG Quanwei, GUO Jianqiu, ZHONG Changhong & LI Zhenjiang faculty of earth Science,{2. University of {3., Wuhan 430074,{2. Sichuan Geological Survey, Chengdu 610000,{2. faculty of earth Science China University of Geosciences Wuhan China Sichuan Geological Survey Chengdu China

Ladinian radiolarian fauna, including Muelleritortis, Baumgartneria, Oertlispongus, Paroertlispongus, Pseudoertlispongus, etc., was discovered from the siliceous rock of the Runiange Formation in the Xianshuihe belt, West Sichuan Province. Geochemical test on five samples from the siliceous rock indicates that SiO2.content varies in 71.16%-90.06% and Si/Al ratio, in 49-71, which shows that the siliceous rock contains more terrigenous mud sediments. The siliceous rock is characterized by the large ratios of Al2.3.(Al2.3.Fe2.3. (0.63.0.81) and Ti/V (>2.), the low ratio of V/Y (2.8), and low vanadium content (2.0}μg/g), which are similar to the geochemical characteristics of continental margin siliceous rock. The Ce/Ce* ratios of the four samples vary in 1.02.1.47 and the LaN/CeN ratio, in 0.75-1.07, which imply that the siliceous rock was deposited in the continental margin basin. But only one sample is similar to the oceanic siliceous rock in REE. Turbidite-siliceous rock bearing radiolarian-basalt assemblage and the geochemical characteristics of the siliceous rock indicate that the Xianshuihe belt is in the strong rift stage in the Ladinian age.

关键词： siliceous rock, radiolarians, Triassic, the Xianshuihe belt, West Sichuan.

Criteria for defining and recognizing the various orders of sequences in outcrop sequence stratigraphy

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Science china earth {2. 2004年第7期47卷 618-629页

作者： WANG Xunlian faculty of earth {2. and Mineral Resources,{3. University of geosciences, Beijing 100083.{3. State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of {2., Nanjing 2.0008,{3. faculty of earth {2. and Mineral Resources China University of Geosciences Beijing China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing China

The regional distribution in different depositional facies belts is here regarded as an important criterion for defining and recognizing the various orders of sequences. The third-order sequence is possibly global in nature, which may be discerned in different depositional facies belts in one continental margin and can be correlated over long distances, sometimes even worldwide. Commonly, correlation of subsequence (fourth-order sequence with time interval of 0.51.5 Ma) is difficult in different facies belts, although some of them may also be worldwide in distribution. A subsequence should be able to discern and correlate within at least one facies belt. The higher-order sequences, including microsequence (fifth-order sequence) and minisequence (sixth-order sequence), are regional or local in distribution. They may reflect the longer and shorter Milankovitch cycles respectively. Sequence and subsequence are usually recognizable in different facies belts, while microsequence and minisequence may be distinguished only in shallow marine deposits, but not in slope and basin facies deposits. A brief discussion is made on the essential conditions for correct identification of sequences, useful methods of study, and problems meriting special attention in outcrop sequence stratigraphy.

关键词： outcrop sequence stratigraphy, facies belt, sequence, subsequence, microsequence, minisequence, meter-scale cyclothem, Milankovitch cycle.

Development of distributed time-variant gain model for nonlinear hydrological systems

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Science china earth {2. 2005年第6期48卷 713-723页

作者： XIA Jun1, 2. WANG Gangsheng1, TAN Ge1, YE Aizhong2.& G. H. Huang3.1. Key Laboratory of Water Cycle & Related Land Surface Processes, Institute of Geographic sciences and Natural Resources Research, Chinese Academy of sciences, Beijing 100101, china 2. State Key Laboratory of Water Resources & Hydropower Engineering sciences, Wuhan University, Wuhan 43.072. china 3. faculty of Engineering, University of Regina, 3.3. Wascana Parkway, Regina, Sask., S4S 0A2. Canada Correspondence should be addressed to Xia Jun Key Laboratory of Water Cycle & Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China State Key Laboratory of Water Resources & Hydropower Engineering sciences Wuhan University Wuhan China faculty of Engineering University of Regina Sask Canada

In this paper, a rainfall-runoff modeling system is developed based on a nonlinear Volterra functional series and a hydrological conceptual modeling approach. Two models, i.e. the time-variant gain model (TVGM) and the distributed time-variant gain model (DTVGM) that are built on the platform of Digital Elevation Model (DEM), Remote Sensing (RS) and Unit Hydro-logical Process were proposed. The developed DTVGM model was applied to two cases in the Heihe River Basin that is located in the arid and semiarid region of northwestern china and the Chaobai River basin located in the semihumid region of northern china. The results indicate that, in addition to the classic dynamic differential approach to describe nonlinear processes in hy-drological systems, it is possible to study such complex processes through the proposed sys-tematic approach to identify prominent hydrological relations. The DTVGM, coupling the advan-tages of both nonlinear and distributed hydrological models, can simulate variant hydrological processes under different environment conditions. Satisfactory results were obtained in fore-casting the time-space variations of hydrological processes and the relationships between land use/cover change and surface runoff variation.

关键词： hydrological process, nonlinearity, time-variant gain model, distributed hydrological model.

Numerically quantifying the relative importance of topography and buoyancy in driving groundwater flow

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Science china earth {2. 2010年第1期53卷 64-71页

作者： YANG JianWen 1,2.FENG ZuoHai 1,LUO XianRong 1 & CHEN YuanRong 1 1 faculty of earth {2.,Guilin University of Technology,Guilin 541004,{3. 2.Department of earth and Environmental {2.,University of Windsor,Windsor,Ontario,N9B 3.4,Canada faculty of earth {2. Guilin University of Technology Guilin China Department of earth and Environmental sciences University of Windsor Windsor Canada

Both topography and buoyancy can drive groundwater flow;however,the interactions between them are still poorly *** this paper,the authors conduct numerical simulations of variable-density fluid flow and heat transport to quantify their relative *** finite element modeling experiments on a 2.D conceptual model reveal that the pattern of groundwater flow depends largely upon the relative magnitude of the flow rate due to topography alone and the flow rate due to buoyancy *** fluid velocity due to topography is greater than that due to buoyancy at large water table gradients,topography-driven 'forced convection' overwhelms buoyancy-driven 'free convection'.When flow velocity due to buoyancy is greater than that due to topography at small water table gradients,mixed free and forced convection takes *** this case,free convection becomes dominant,but topography-driven flow still plays an important role since it pushes the free convection cells to migrate laterally in the downhill ***,hydrothermal fluid flow remains changing periodically with time and no steady state can be *** presence of a low-permeability layer near the surface helps eliminate the topography effect on the underlying free convection.

关键词： hydrothermal flow free convection forced convection topography buoyancy finite element modeling