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Science China Earth Sciences 2011年第4期54卷 519-527页

作者： GUO Yi HU YaoWu ZHU JunYing ZHOU Mi WANG ChangSui Michael P. RICHARDS Department of Human Evolution Max-Planck Institute for Evolutionary Anthropology Leipzig D-04103 Germany Lab of Human Evolution Institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Beijing 100044 China Department of Scientific History andArchaeometry Graduate University of Chinese Academy of Sciences Beijing 100049 China Department of Cultural Heritage and Museology School of Humanities Zhejiang University Hangzhou 310028 China Hubei Provincial Institute of Cultural Relics and Archaeology Wuhan 430077 China

Previous studies on the Rice-Millet （foxtail millet and common millet） Blended Zone in Chinese Neolithic have not clearly addressed such questions as the importance of primitive rice-millet mixed agriculture to human lifestyle and livestock managements within this region, the relationship among the development of the agriculture, paleoenvironment, and cultural interactions, and so on. Here stable carbon and nitrogen isotope analysis of human and pig bones from the Qinglongquan site was conducted, covering two cultural phases, namely the Qujialing Culture （3000 BC to 2600 BC） and the Shijiahe Culture （2600 BC to 2200 BC）. Based on this analysis, we further discussed the diets of ancient humans and pigs in the site, investigated the importance of rice-millet mixed agriculture to human and pig diets, and explored the relationship among the primitive rice agriculture and millet agriculture, cultural interactions, and paleoenvironment. The δ^13C values of human bone collagen （-16.7‰ to -12.4‰, averaging -14.6‰±1.3‰, n=24） revealed that both C3 and Ca foods were consumed, probably from the contribution of rice （C3 plant） and millets （C4 plants） due to the coexistence of these crops at this site. In addition, the human mean δ^13C value suggested that millet agriculture was only minor in human diets. The human δ^15N values （6.6‰ to 10.8‰, averaging 9.0‰±1.2‰, n=24） showed that animal resources played a significant role in human diets, and varied greatly. The mean δ^13C value of the pigs （-14.3‰±2.5‰, n=13） was quite similar to that of the humans, but the mean δ^15N value of the pigs was slightly less （1.3‰） The similar δ^13C and δ^15N values between humans and pigs suggested that the pigs consumed a lot of humans＇ food remains. No correlations of the δ^13C and δ^15N values between humans and pigs showed that both human and pig diets were based mainly on plant foods, which might be related to highly developed rice-millet mixed agriculture at that time. In comparison with the

关键词： paleodiet the Rice-Millet Blended Zone stable isotope cultural interaction paleoenvironment

Formation and influencing factors of carbonate source rock of the Lower Permian Chihsia Formation in Chaohu region, Anhui Province

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Science China Earth Sciences 2011年第12期54卷 1926-1939页

作者： LIU Feng CAI JinGong LU BingQuan XU JinLi State Key Laboratory of Marine Geology Tongji University Shanghai 200092 China

Highly-mature carbonate source rock is essential to the exploration of oil and gas in southern China. In this study, the carbonate strata in the relatively well-developed Lower Permian Chihsia Formation (located in Chaohu, Lower Yangtze) were targeted, and the formation and influencing factors of source rock were discussed based on paleoenvironment reconstruction using comprehensive sedimentology, palynofacies, and organic geochemistry data. The results demonstrate that the Chihsia Formation is oxygen-deficient biogenic carbonate sediments, with marked variations in the organic and inorganic components, formed during a period of Permian transgression. The formation of source rock is the combined result of high bioproductivity and oxygen-deficient environment generated by transgression and oxygenation events which frequently occurred during transgression periods. Source rock was affected by self-dilution effects and diagenesis, causing its heterogeneous distribution in many intervals. Source rock is over 40 m thick, and can be identified based on its different organic, biological, and mineral composition characteristics. The carbonate rock appears to require no specific clay content in order to become a source rock. The combination of sedimentology, palynofacies, and organic geochemistry has provided an effective means for evaluating and predicting high-maturity carbonate source rock in the region.

关键词： lower Yangtze Chihsia Formation palynofacies paleoenvironment carbonate source rock heterogeneous distribution

Molecular fossil and paleovegetation records of paleosol S4 and adjacent loess layers in the Luochuan loess section, NW China

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Science China Earth Sciences 2008年第3期51卷 321-330页

作者： ZHANG HuCai YANG MingSheng ZHANG WenXiang LEI GuoLiang CHANG FengQin PU Yang FAN HongFang Key Laboratory of Western China’s Environmental Systems Ministry of EducationCollege of Earth and Environment SciencesLanzhou UniversityLanzhou 730000China State Key Laboratory of Lake and Environment Sciences Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China

Using gas chromatography-mass spectrometry (GC-MS) technique, a series of biomarkers were identi- fied, including n-alkanes, n-alkane-2-ones, isoprenoid etc. from the loess-paleosol samples collected from the S4 and adjacent L5, L4 of the Luochuan loess section, Northwestern China. Based on these data, especially n-alkanes and high-resolution magnetic susceptibility and grain size data, the pa- leoenvironment and paleovegetation history during S4 was reconstructed. The CPI (Carbon Predomi- nance Index) and correlation between n-alkanes and magnetic susceptibility and grain size data dem- onstrated that the molecular fossils in paleosol and loess layers can reflect the vegetation condition during the loess-paleosol formation, if the allochthonous organic inputs could be excluded reasonably. The ACL (average chain length) index is correlated well with paleomagnetic susceptibility and grain size variations, displaying their good synchrony with warm and humid climate. However, it relatively lagged behind the paleomagnetic susceptibility and the grain size variations when the climate began to deteriorate. During the formation period of paleosol, the n-alkanes was dominated by C31 homologue, indicating that the primary organic input originated from herbs. Our study also demonstrated that the herbs were more flourish than wood plants in Loess Plateau, especially in the Luochuan area during the warm and humid phase, and there was no typical forest vegetation developed in the studied period.

关键词： paleoenvironment Paleosol S4 Luochuan loess section biomarker paleovegetation

Characteristics and geological significance of carbon and oxygen isotopes of the Permian Lucaogou Formation dolomite in the southern Junggar Basin, northwestern China

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Journal of Palaeogeography 2024年第4期13卷 862-882页

作者： Gang Liu Guo-Zhi Wang Na Li Hong-Ling He Nan-Nan Lu Qing Lei Zi-Ang Wang College of Earth and Planetary Sciences Chengdu University of TechnologyChengdu 610059Sichuan ProvinceChina National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu University of TechnologyChengdu 610059Sichuan ProvinceChina Hebei Survey Institute of Coal Geology Xingtai 054000Hebei ProvinceChina sichuan Earthquake Agency Chengdu 610041Sichuan ProvinceChina

Anomalously positive δ^(13)C values in ancient dolomites are very *** gray argillaceous rocks of the lacustrine sediments of the Permian Lucaogou Formation are important source rocks in the Junggar Basin,and dolomites of varying thicknesses from 10 cm to 150 cm are often interspersed in argillaceous *** on the study of petrographic sections,this paper systematically analyzes the carbon and oxygen isotopes of dolomite and discusses the causes of abnormally high carbon isotope values and their significance in reconstructing paleoenvironment and *** results show that carbon isotope values are abnormally high in the dolomite of Lucaogou Formation,and the δ^(13)C value is between+3.2‰PDB and+19.6‰PDB,with an average of+9.7‰*** δ^(18)O values range from-17.4‰PDB to-1.7‰PDB,with an average of-8.1‰*** the lower part to the upper part of the Lucaogou Formation,the carbon isotope value gradually increases and becomes increasingly positive,and the carbon isotope of the dolomite deposited near the shore is more positive than that of the dolomite deposited far from the *** anomalously positive δ^(13)C of the dolomite is mainly caused by microbial methanogenesis,with some contribution from *** are mainly distributed at the redox *** controls the salinity and fluctuation of the redox interface in sedimentary *** positive deviation difference in carbon isotopes between nearshore and offshore sedimentary dolomites may be related to the location of the redox interface during ***,the petrographic features and carbon and oxygen isotope signatures of the sections reflect the gradual evolution of the paleolake from a hydrologically open environment to a hydrologically closed one and the possible transition of the paleoclimate from a relatively warm to an arid condition,which is possibly a geochemical response to global climate change in the Permian period.

关键词： Junggar Basin Lucaogou Formation Dolomite Positive carbon isotope anomaly paleoenvironment

Investigation of Organic Matter Sources and Depositional Environment Changes for Terrestrial Shale Succession from the Yuka Depression: Implications from Organic Geochemistry and Petrological Analyses

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Journal of Earth Science 2023年第5期34卷 1577-1595页

作者： Shiming Liu Lian Jiang Bangjun Liu Cunliang Zhao Shuheng Tang Furong Tan Key Laboratory of Resource Exploration Research of Hebei Province Hebei University of EngineeringHandan 056038China Department of Earth and Environmental Sciences and MQ Marine Research Centre Macquarie UniversitySydney NSW 2109Australia School of Energy Resource China University of GeosciencesBeijing 100083China Department of Geology Northwest UniversityXi'an 710069China

Continental organic-rich shales are well developed in the Dameigou Formation within the Yuka Depression of the Qaidam Basin. Here, the Rock-Eval pyrolysis, biomarkers, organic petrology, and stable carbon isotope have been carried out on the Middle Jurassic Dameigou Formation source rocks from the northwest part of Yuka Depression, Qaidam Basin in order to study their thermal maturity, source of organic matter(OM), and palaeoenvironment changes. The Rock-Eval pyrolysis data(e.g., T_(max)), vitrinite reflectance, and biomarker-derived thermal maturity parameters(e.g., carbon preference index, Ts/(Ts+Tm), C_(29)Ts/(C_(29)Ts+C_(29)αβ hopane), C_(30) αβ/(αβ+βα) hopanes, C_(29)ααα 20S/(20S+20R) steranes, and C_(29)αββ/(αββ+ααα) steranes) suggest all studied samples stay between immature and low mature stage. The maceral compositions, stable carbon isotope compositions, n-alkane distributions, and biomarker-derived source parameters(e. g., C_(27)/C_(29)ααα 20R sterane, ternary diagram of C_(27)-C28-C_(29)steranes, C24 tetracyclic terpane) indicate both aquatic organisms and higher plants are the source of OM in the shales, but land plants are dominant. Generally low gammacerane concentration and environment-related parameters(e. g., cross-plots of C_(27)/C_(29)ααα 20R sterane vs. Pr/Ph) indicate these source rocks may be derived from lacustrine and fluvial-deltaic environments with fresh water, which is also supported by the variations of stable carbon isotopes from OM in the source rocks. However, the stable carbon isotope compositions of OM in the source rocks were influenced by multiple factors(e.g., source types and depositional environment) in the Yuka Depression. Slightly brackish condition is recorded in the upper part of the ZK6-1 well favor the formation of lacustrine algae, as confirmed by high contents of C_(27) steranes and short-chain n-alkanes. The variation of reducing to oxidizing condition of study area is possibly associated with the periodical flooded r

关键词： biomarker stable carbon isotopes dameigou formation lacustrine sediments paleoenvironment petroleum geology

Carbon and sulfur isotopic compositions of basal Datangpo Formation, northeastern Guizhou, South China:Implications for depositional environment

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Progress in Natural Science:Materials International 2008年第4期18卷 421-429页

作者： Xi Chen, Da Li, Hong-Fei Ling , Shao-Yong Jiang State Key Laboratory for Mineral Deposit Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China State Key Laboratory for Mineral Deposit Research Department of Earth Sciences Nanjing University Nanjing 210093 China

Isotopic compositions of Mn-carbonate and organic carbon from the same individual samples and sulfur isotopic compositions of pyrites in the basal Datangpo Formation were analyzed. Highly 34S-enriched pyrites (d34Spyrite=31.7-59.4‰) were precipitated in rel- atively occlusive pore water under anoxic condition in sediments, which is consistent with the observation of large and scattered pyrite framboids. The sulfidic deep ocean was not "oxidized" in the early Datangpo interglacial interval, thus the level of seawater sulfate remained low and marine d34Ssulphate remained high. Low d13Ccar (average 7.4‰) and abnormal relationship between d13Ccar and frac-tionation (Dcar-org) imply that the negative d13Ccar excursion may have resulted from oxidation of part of a large organic carbon reser-voir. High Dcar-org (average 25.1‰) implicates high CO2 level in the atmosphere. Small standard deviation (1.0‰) of d13Ccar values indicates the Mn-carbonate was precipitated near the water-sediment interface under dysoxic conditions rather than in occlusive pore water in sediments.

关键词： Cisotope S isotope paleoenvironment Datangpo Mn-carbonate

The oleaginous Botryococcus from the Triassic Yanchang Formation in Ordos Basin,Northwestern China:Morphology and its paleoenvironmental significance

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The oleaginous Botryococcus from the Triassic Yanchang Forma...

Environmental magnetic studies of lacustrine sediments

中国科学院地质与地球物理研究所第十届(2010年度)学术年会

作者： Li-ming Ji~(a,*),Kui Yan~(b,c),Fan-wei Meng~(b,c),Min Zhao~(a,d) a Key Laboratory of Petroleum Resources Research,Institute of Geology and Geophysics,Chinese Academy of Sciences,Lanzhou,Gansu Province 730000,China b State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing,jiangsu Province 210008,China c Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing,jiangsu Province 210008,China d Graduate School of Chinese Academy of Science,Beijing 100069,China

High abundance but rather low diversity algal fossils were found in the hydrocarbon source rocks of the Ch 7-2-Ch 7-3 section,Triassic Yanchang Formation in the Xifeng area of southwest Ordos Basin,which are mainly composed of prolific Leiosphaeridia and *** colonies are of various forms;the majority is nubbly,with some of cluster and cotton *** nubbly colonies appear globular, cordiform,ternate petal,obtuse triangle,chrysanthemum shape and so *** Botryococcus are saffron or brown and are frequently covered with clay under transmission microscope,and shows strong yellow and light brown under fluorescence *** could live in freshwater and brackish *** Botryococcus colonies that lived in fresh water are small with small single cells arranged radially,with undulant or indented *** Botryococcus colonies that lived in brackish water are bigger, with larger single cells arranged irregularly,with slippery *** most of Botryococcus are discovered from the organic-rich argillaceous sediment with abundant pyrites in the semi- and deep-lake facies,and shows they were preserved in low-energy reducing *** characteristics of various microfossils and the present of Pediastrum in the phytoplankton flora indicate that they are in situ or near *** lake area of the Ordos Basin was gradually expanding and reaching its most extensive flood surface in the Ch 7 of Yanchang Formation interval during the Middle and Late Triassic, with warm climate,plentiful rainfall,and luxuriant vegetation,as determined by the environmental analysis with Botryococcus in Xifeng *** presence of two ecological types of Botryococcus indicates that the salinity of lake water was fluctuating in the Ch 7 *** occurrence of symbiotic acritarchs and geochemical salinity indices show that the Ordos Lake was a typical fresh-water lake,which was gradually desalted,and its salinity fluctuation was narrow durin

关键词： Ordos Basin Triassic Yanchang Formation Hydrocarbon source rocks Botryococcus paleoenvironment

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Chinese Science Bulletin 2002年第7期47卷 613-616页

作者： HU Shouyun, DENG Chenglong, E. Appel & K. L. VerosubNanjing Institute of Geography and Limnology, Nanjing 210008, China Institute of Geology and Geophysics, Beijing 100101, China Institut fur Geologic, Universitat Tubingen, 72076 Tubingen, Germany Departm Nanjing Institute of Geography and Limnology Nanjing China Institute of Geology and Geophysics Beijing China Institut für Geologie Universität Tübingen Tübingen Germany Department of Geology University of California Davis USA

In recent decades, environmental magnetism has become an important method for studying past global climatic and environmental changes. For an environmental magnetic study, it is important to understand the magnetic properties of various magnetic minerals in lacustrine sediments and the processes involved in the formation, transport, and preservation of these magnetic minerals. The magnetic response of lacustrine sediments to climatic change may vary widely from lake to lake. To reconstruct the processes contributing to paleoclimatic and paleoenvironmental change, it is, therefore, necessary to derive a complete understanding of the potential origin of the magnetic signal observed.

关键词： rock magnetism paleoclimate paleoenvironment lacus-trine sediments.

Climate variability recorded by n-alkanes of paleolake sediment in Qaidam Basin on the northeast Tibetan Plateau in late MIS3

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Science China Earth Sciences 2010年第6期53卷 863-870页

作者： PU Yang ZHANG HuCai LEI GuoLiang CHANG FengQin YANG MingSheng ZHANG WenXiang LEI YanBin YANG LunQing PANG YouZhi State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjing 210008China Graduate University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Boyang Lake MOESchool of Environmental and Chemical EngineeringNanchang UniversityNanchang 330031China

Here we combine n-alkanes preserved in a shell bar section from Qarhan paleolake, Qaidam Basin with the other sedimentary proxies to elucidate the lake evolution process during the period 39.7 to 17.5 14C ka BP (calibrated age ranges from 43.5 to 22.4 cal. ka BP). In different stages, the n-alkane homologues exhibited different distribution modes indicative of variations in the surrounding vegetation and the hydrologic condition of the lake. The n-alkanes proxies (CPIh, ACLh, Paq) have the same trends as the summer solar insolation variation, implying that the summer insolation is the most important climatic factor driving the environmental changes and also indirectly controls lake evolution on the Tibetan Plateau. CPIh and ACLh as well as the total pollen concentration appear to show a trend comparable with methane concentration record from the GRIP ice core that reflected the Dansgaard-Oeschger events. This demonstrates that the paleoclimate variations in Qarhan area generally agree with global climate change and show rapid oscillations in late MIS3. These findings provide the latest molecular fossil evidence from paleolake sediments to confirm that lake evolution on Tibetan Plateau in late MIS3 was closely associated with enhanced summer insolation.

关键词： paleolake sediment molecular fossil n-alkane paleoclimate paleoenvironment solar insolation