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Spatio-temporal carbon isotope variation during the Ediacaran period in South c.ina and its impact on bio-evolution

Science c.ina Earth Sciences 2009年第10期52卷 1520-1528页

作者： WANG XinQiang1 & SHI XiaoYing1,2.1 School of Earth Science and Mineral Resources, c.ina university of {2., beijing 100083, c.ina 2.State Key Laboratory of Geological Processes and Mineral Resources, beijing 100083, c.ina School of Earth Science and Mineral Resources China University of Geosciences Beijing 100083 China State Key Laboratory of Geological Processes and Mineral Resources Beijing 100083 China

The Ediacaran period is characterized by the extremely negative carbon isotope anomalies and great biotic evolution in Earth history. At least four negative carbon isotope anomalies have been reported from this interval in South c.ina so far. It is traditionally argued that the isotope variations can be used as a useful tool for global correlation of Ediacaran succession; however, more and more researches argued against this idea. We reviewed the previously published carbon isotope data in South c.ina, and distributed the mean values of a certain time to the paleogeographic maps. The results show that the carbon isotope values (δ13c) vary greatly in different environments, but a clear tendency of becoming lighter from shallow platform to deep basin, with a maximum variation up to 1‰ Moreover, the important changes in Ediacaran biota, marked by the introducing of new taxa or ecologic groups, seemed to always postdate the negative anomalies but coincide with the positive shift. If the negative excursions represented the oxidation of a large dissolved organic carbon (DOc) reservoir in the ocean, the diverse Ediacaran organisms and the carbon isotope anomalies may suggest totally different environments: oxic and anoxic/euxinic. We also suggest that the elim{2.tion of euxinic state through precipitation of pyrites is one of the important environment factors in prompting the Ediacaran bio-evolution.

关键词： Ediacaran South c.ina carbon isotope spatio-temporal variations bio-evolution

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Mechanism for calcite dissolution and its contribution to development of reservoir porosity and permeability in the Kela 2.gas field,Tarim Basin,c.ina

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Science c.ina Earth Sciences 2008年第4期51卷 567-578页

作者： YU BingSong1,3, DONG HailLiang2.3 & RUAN Zhuang1,3 1 State Key Laboratory of Geological Processes and Mineral Resources, c.ina university of {2., beijing 100083, c.ina 2.Department of Geology, Miami university,Oxford, OH 45056, USA 3 Geomicrobiology Laboratory, c.ina university of {2., beijing, 100083, c.ina State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Beijing 100083 China Department of Geology Miami University Oxford OH 45056 USA Geomicrobiology Laboratory China University of Geoscien

This study is undertaken to understand how calcite precipitation and dissolution contributes to depth-related changes in porosity and permeability of gas-bearing sandstone reservoirs in the Kela 2.gas field of the Tarim Basin, Northwestern c.ina. Sandstone samples and pore water samples are col-lected from well KL2.1 in the Tarim Basin. Vertical profiles of porosity, permeability, pore water chem-istry, and the relative volume abundance of calcite/dolomite are constructed from 3600 to 4000 m below the ground surface within major oil and gas reservoir rocks. Porosity and permeability values are in-versely correlated with the calcite abundance, indicating that calcite dissolution and precipitation may be controlling porosity and permeability of the reservoir rocks. Pore water chemistry exhibits a sys-tematic variation from the Na2.O4 type at the shallow depth (3600-3630 m), to the NaHcO3 type at the intermediate depth (3630―3695 m),and to the cacl2.type at the greater depth (372.―3938 m). The geochemical factors that control the calcite solubility include pH, temperature, pressure, ca2. concen-tration, the total inorganic carbon concentration (ΣcO2., and the type of pore water. Thermodynamic phase equilibrium and mass conservation laws are applied to calculate the calcite saturation state as a function of a few key parameters. The model calculation illustrates that the calcite solubility is strongly dependent on the chemical composition of pore water, mainly the concentration difference between the total dissolved inorganic carbon and dissolved calcium concentration (i.e., [ΣcO2. -[ca2.]). In the Na2.O4 water at the shallow depth, this index is close to 0, pore water is near the calcite solubility. calcite does not dissolve or precipitate in significant quantities. In the NaHcO3 water at the intermedi-ate depth, this index is greater than 0, and pore water is supersaturated with respect to calcite. Massive calcite precipitation was observed at this depth interval and

关键词： calcite dissolution porosity thermodynamic Tarim Basin

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Paleocontinental Reconstruction:Methodology,computer Software and an Example of Application

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Journal of Earth Science 1993年第1期12卷 12-18页

作者： Li Xiangc.ina university of {2. , beijing 100083

Paleocontinental reconstruction is of the nature of multidisciplinary analysis . This paper discusses the significance of some more important disciplines , including paleomagnetism , paleoclimatology and paleobiogeography. Top attention should be paid to the synthetic analysis and geological explanation of geophysical data . Reassembling of the paleocontinents by geometric similarities is preliminary, geological considerations should receive more attention . Several rules constraining the reconstruction are proposed and Eider poles used to reassemble some separated Precambrian median massifs to their mother continents are given . A computer software for paleocontinental reconstruction , GUDALU , is introduced . The software is flexible in that it gives the user maximum freedom to demonstrate his or her geological opinions by providing means of organizing geographic data and rotational parameters ,many kinds of map projection of different features and dynamic editing of the reconstruction maps . Finally, an example of Mesoproterozoic reconstruction is demonstrated .

关键词： paleocontinental reconstruction plate fit . synthetic analysis computer software.

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South c.ina's Gondwana connection in the Paleozoic:Paleomagnetic evidence

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Progress in Natural Science:Materials International 2004年第1期14卷 86-91页

作者： ZHANG Shihong*(School of Earth Sciences and Resources, c.ina university of {2., beijing 100083, c.ina) c.ina Univ Geosci Sch Earth Sci & Resources Beijing 100083 Peoples R China

The reconstruction in which the South c.ina Block (ScB) lies along the Great India Australia region of Gondwana margin is tested by using existing Paleozoic paleomagnetic data. Under the proposed reconstruction, all six high quality paleopoles from the ScB between the Early cambrian and late Early Devonian (～400 Ma) are in good agreement with coeval paleopoles from Gondwana. Thereafter, the apparent polar wander paths for the ScB and Gondwana diverge markedly. This indicates that the ScB had been part of Gondwana and the connection was intact from at least Early cambrian until late Early Devonian, but they began to separate by late Middle Devonian (～375 Ma).

关键词： South c.ina block Gondwana paleomagnetism reconstruction

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convergence,Scalarization and continuity of Minimal Solutions in Set Optimization

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Journal of the Operations Research Society of c.ina 2024年第3期12卷 773-793页

作者： Karuna c.S.Lalitha Department of Mathematics University of DelhiDelhiDelhi110007India Department of Mathematics University of Delhi South CampusNew DelhiDelhi110021India

The paper deals with the study of two different aspects of stability in the given space as well as the image space,where the solution concepts are based on a partial order relation on the family of bounded subsets of a real normed linear *** first aspect of stability deals with the topological set convergence of families of solution sets of perturbed problems in the image space and Painlevé–Kuratowski set convergence of solution sets of the perturbed problems in the given *** convergence in the given space is also established in terms of solution sets of scalarized perturbed *** second aspect of stability deals with semicontinuity of the solution set maps of parametric perturbed problems in both the spaces.

关键词： Topological convergence Painlevé-Kuratowski convergence Upper semicontinuity Lower semicontinuity Stability Scalarization

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Performance of evolutionary optimized machine learning for modeling total organic carbon in core samples of shale gas fields

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Petroleum 2024年第1期10卷 150-164页

作者： Leonardo Goliatt c.M.Saporetti L.c.Oliveira E.Pereira Department of computational and Applied Mechanics Federal University of Juiz de ForaJuiz de ForaBrazil Department of computational Modeling Polytechnic InstituteRio de Janeiro State UniversityNova FriburgoBrazil Petrobras Rio de JaneiroBrazil Department of Stratigraphy and Paleontology Rio de Janeiro State UniversityRio de JaneiroBrazil

Rock samples'TOc content is the best indicator of the organic matter in source *** origin rock samples’analysis is used to calculate it manually by *** method requires time and resources because it relies on samples from many well intervals in source ***,research has been done to aid this *** learning algorithms can estimate total organic carbon instead of well logs and stratigraphic *** light of these efforts,the current work present a study on automating the total organic carbon estimation using machine learning approaches improved by an evolutionary methodology to give the model flexibility and *** algorithms,differential evolution,particle swarm optimization,grey wolf optimization,artificial bee colony,and evolution strategies were used to improve machine learning models to predict *** six metaheuristics were integrated into four machine learning methods:extreme learning machine,elastic net linear model,linear support vector regression,and multivariate adaptive regression *** samples from the YuDong-Nan shale gas field,located in the Sichuan basin,were used to evaluate the hybrid *** findings show that combining machine learning models with an evolutionary algorithms in a hybrid fashion produce flexible models that accurately predict *** results show that,independent of the metaheuristic used to guide the model selection,optimized extreme learning machines attained the best performance scores according to six *** hybrid models can be used in exploratory geological research,particularly for unconventional oil and gas resources.

关键词： Total organic carbon Hybrid models Automated machine learning Evolutionary algorithms Geology

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The control of syndepositional faulting on the Eogene sedimentary basin fills of the Dongying and Zhanhua sags, Bohai Bay Basin

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Science c.ina Earth Sciences 2004年第9期47卷 769-782页

作者： LIN changsong1, ZHENG Herong2. REN Jianye1, LIU Jingyan1 & Qiu Yigang1 1. Department of Energy Geology, c.ina university of {2., beijing 100083, c.ina 2. Petroleum Exploration and Production Institute, Sino-Petroleum and chemistry cooperation, beijing 100083, c.ina c.ina Univ Geosci Dept Energy Geol Beijing 100083 Peoples R China Sino Petr & chem cooperat Petr Explorat & Prod Inst Beijing 100083 Peoples R China

The Dongying and Zhanhua sags are the major hydrocarbon exploration and produc- tion subbasins in the Bohai Bay Basin. Integrated analysis of the sedimentary basin fills has shown that the syndepositional faults and their arrangement styles exerted an important influ- ence on the development and distribution of the Eogene depositional systems. The sedimentary filling evolution of the subbasins reflects the general control of the episodic rifting process. The major long-term active normal faults formed a series of paleogeomorphic accident or slopebreak zones that commonly delineated the subsidiary palaeostructural units and the depositional facies tracts and constrained the general distribution of sedimentary facies zones. The central sag boundary fault slopebreak zones usually determined the distribution of the depocenters of ter- restrial clastic depositional systems, particularly the lowstand fans or deltaic depositional sys- tems, and have proven to be the economically important targets for the exploration of subtle sandstone reservoirs. A variety of syndepositional fault arrangement patterns, including the par- allel, en echelon, combo-like, broom-like fault systems and the fault overlap or transfer zones, have been recognized in the subbasins. They generated distinctive geomorphic features and exerted a direct influence on sediment dispersal and sandbody distribution during the Eogene synrift stage. It is the key for the prediction of depositional systems tracts and reservoir sand- stones to investigate the activity and distribution of the fault slopebreak zones and reconstruct the structural paleogeomorphy in different basin filling stages of the basin evolution.

关键词： episodic rifting, fault slopebreak zone, depositional pattern, Bohai Bay Basin.

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The role of aerial algae in the formation of the landscape of the Yunnan Stone Forest,Yunnan Province, c.ina

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Science c.ina Earth Sciences 2004年第9期47卷 846-864页

作者： TIAN Youping1,3, ZHANG Jie2. SONG Linhua1 & BAO Haosheng2.1. Institute of Geographic Sciences and Natural Resources Research, chinese Academy of Sciences, beijing 100101, c.ina 2. Department of Geography, Nanjing {2., Nanjing 2.0093, c.ina 3. School of Earth Sciences and Resources, c.ina {2. of geosciences, beijing 100083, c.ina Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Department of Geography Nanjing University Nanjing 210093 China School of Earth Sciences and Resources China University of Geosciences Beijing 100083 China

Aerial algae on the surface of carbonate rocks at the Stone Forest, Shilin county, Yunnan Province, c.ina, and their bioerosion were investigated in the field and studied in the laboratory in detail. Through the observation, identification and statistics of more than one hun- dred algal samples and rock samples with the optical microscopes (stereomicroscope, biological microscope) and the scanning electronic microscope (SEM), the relationships between erosional forms on the surface of the Stone Forest and algae and/or algal communities and the genetic mechanism for the formation of erosional forms were analyzed. It is suggested that aerial algae play an active role in bioerosive processes that may affect the formation of karst erosional forms. These effects include both direct and indirect ones. The direct effect is the initiative control (algal shape-controlling role) of algae on the formation of karst forms of various scales, mostly mi- cro-scale (cale (10-3-10-1m) erosional forms. The algal shape-controlling roles can be divided into the algal individual shape-controlling role and the algal community shape-controlling role. The former mostly controls the formation of micro-scale erosional forms, while the latter mostly controls the formation of micro-scale and smaller minor-scale erosional forms. The indirect effect refers to the promoting role of algae in the formation of karst forms, which may affect the formation of karst forms of all types and scales. The bioerosion of algae accelerates the weathering process of the whole Stone Forest karst landforms.

关键词： aerial algae, bioerosion, the Stone Forest, Yunnan Province, c.ina.

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Flotation Separating Rutile from calcium and Silicon Gangue Minerals

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Rare Metals 2001年第4期20卷 205-208页

作者： Hao Ding1, HaiLin 2.1) beijing Academy of Building Materials, beijing 100041,{2. 2. university of Science and Technology beijing, beijing 100083,{2. beijing Acad Bldg Mat Beijing 100041 Peoples R China Univ Sci & Technol beijing Beijing 100083 Peoples R China

Rutile separation from calcite, apatite and quartz by flotation was investigated. The results show that the rutile separation from calcium and silicon gangue minerals can be realized with alkyl-imino-bismethylene phos... 详细信息

关键词： rutile calcium and silicon gangue minerals flotation separate alkyl-imino-bismethylene phosphoric acid sodium hexametaphosphate

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Incised valley filling deposits:an important pathway system for long-distance hydrocarbon migration—a case study of the Fulaerji Oilfield in the Songliao Basin

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Petroleum Science 2009年第3期6卷 230-238页

作者： Xin Renchen Liu Hao Li Guifan School of Ocean Sciences China University of Geosciences Beijing 100083 China School of the Earth Sciences and Resources China University of Geosciences Beijing 100083 China

In this paper, incised valley filling deposits, which formed an important pathway system for long-distance hydrocarbon migration, are discussed in detail based on core and logging data. The sequence SQy2. of the cretaceous Yaojia Formation is the main hydrocarbon-bearing layer in the Fulaerji Oilfield. The hydrocarbon source of the oilfield is the Qijia-Gulong Sag which is about 80 km away from the Fulaerji Oilfield. The transport layer of long-distance hydrocarbon migration is the overlapped sandstone complex which fills the incised valley. The incised valley developed during the depositional period from the late Qingshankou Formation to the early Yaojia Formation of cretaceous （SQqna-SQy0 was about 70 km long and 2. km wide, and extended in the NW-SE direction. The overlapped filling of the incised valley mainly occurred in the expanding system tract of the third-order sequence SQy2. （ESTy2.）. Towards the basin, incised valley filling deposits overlapped on the delta developed in the early period, and towards the basin margin, incised valley filling deposits were covered by the shore-shallow lacustrine sandy beach bar developed in the maximum flooding period. All of the delta, the incised valley filling and the shore-shallow sandy beach bar are sandstone-rich, and have high porosity and permeability, and can form an effective hydrocarbon migration and accumulation system. Deltaic sand bodies collected and pumped hydrocarbon from the active source, incised valley filling depositional system completed the long-distance hydrocarbon migration, and lithological traps of shore-shallow lacustrine sandy beach bar accumulated hydrocarbon. The incised valley filling sequences are multi-cycle： an integrated shortterm filling cycle was developed on the erosion surface, and the sequences upward were mud-gravel stone, medium-fine sandstone containing terrigenous gravels and muddy pebbles with cross bedding, silty mudstone with ripple bedding, and mudstone. The incised valley fi

关键词： Songliao Basin Fulaerji Oilfield Yaojia Formation incised valley filling migration pathway system

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