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Response to the Lomagundi-Jatuli Event in the southwestern margin of the Yangtze Plate:Evidence from the carbon and oxygen isotopes of the Paleoproterozoic Yongjingshao Formation

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China Geology 2023年第1期6卷 50-60页

作者： Jun-ping Liu Wei Yin Shi-pan Yang Jiang-tai Zhao Wen-tao Zeng Feng Tang Shi-jun He Wei-ke Li School of Earth Sciences and Resources China University of GeosciencesBeijing 100083China Yunnan Institute of Geological Survey Kunming 650216China Key Laboratory of Sanjiang Metallogeny and Resources Exploration and Utilization MNRKunming 650051China Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China The Second Geological Institute of China Metallurgical Geology Bureau Fuzhou 350108China

The Lomagundi-Jatuli Event(LJE)refers to the significant positive carbon isotope excursion in seawater constituents that occurred immediately after the increase in atmospheric oxygen content during the Paleoproterozoic(2.22-2.06 Ga).Theδ^(13)C values of 46 dolostone samples collected from the Paleoproterozoic Yongjingshao Formation varied in the range of 0.05‰-4.95‰(V-PDB;maximum:4.95‰)in this study,which may be related to the multicellular eukaryotes in the Liangshan Formation in the Yimen *** are much higher than theδ^(13)C values of marine carbonates(-1.16‰on average).Theδ^(13)C values of other formations in the Paleoproterozoic Yimen Group are *** notable positive carbon isotope anomalies of the Yongjingshao Formation indicate the response to the LJE at the southwestern margin of the Yangtze Block,which is reported for the first ***,they are comparable to theδ^(13)C values of carbonates in the Dashiling Formation of the Hutuo Group in the Wutaishan area in the North China Craton,the Wuzhiling Formation of the Songshan Group in the Xiong'er area,Henan Province,and the Dashiqiao Formation of the Liaohe Group in the Guanmenshan area,Liaoning ***,it can be further concluded that the LJE is a global *** study reveals that LJE occurred in Central Yunnan at 2.15-2.10 Ga,lasting for about 50 *** macro-columnar,bean-shaped,and microfilament fossils and reticular ultramicrofossils of multicellular eukaryotes in this period were discovered in the Liangshan Formation of the Yimen *** are the direct cause for the LJE and are also the oldest paleontological fossils ever *** major events successively occurring in the early stage of the Earth include the Great oxygenation Event(first occurrence),the global Superiortype banded iron formations(BIFs),the Huronian glaciation,the Great oxygenation Event(second occurrence),the explosion of multicellular eukaryotes,the positive carbon isotope excursion,and the global a

关键词： Lomagundi-Jatuli Event Eucaryon Paleoproterozoic Bean-shaped fossil Micro-filament fossil Micro-columnar fossil carbon and oxygen isotopes Yangtze Plate Geological survey engineering China

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Distribution of carbon and oxygen isotopes in theSequence Stratigraphic Framework of the Middle andUpper Proterozoic in the Ming Tombs Area, Beijing

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Acta Geologica Sinica(English Edition) 1998年第2期72卷 207-216页

作者： LI Rufeng University of Petroleum Shuiku Road Changping Beijing 102200

Abstract: This paper discusses the distribution pattern and geological significance of the carbon and oxygen isotopes (δ13C and δ18O) in the depositional sequences of Gaoyuzhuangian, Yangzhuangian and Wumishanian ages of the established Middle and Upper Proterozoic sequence stratigraphic framework in the Ming Tombs area lying in western Yanshan Mountain of Beijing. Besides, sketchy determination of δ13C and δ18O was also performed for other formations and members. The analytical results show the following: under the condition of clear-water carbonate sediments, δ13C and δ18O, featuring smaller variation of δ13C but larger variation of δ18O, can well delineate the relative change of sea level, which reflects the difference of primary sedimentary settings; in the presence of terrigenous substances, δ13C values vary greatly while δ18O slightly; the carbon and oxygen isotopes show marked changes at sequence boundaries. Besides, particular patterns can be found in regard to the distribution of carbon and oxygen isotopes within the sequences.

关键词： Ming Tombs in the western Yanshan Mountains of Beijing Middle and Upper Proterozoic sequence stratigraphy carbon and oxygen isotopes

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Genesis mechanism and Mg isotope difference between the Sinian and Cambrian dolomites in Tarim Basin

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Science China Earth Sciences 2023年第2期66卷 334-357页

作者： Guangyou ZHU Xi LI Tingting LI Lei ZHOU Yuxuan WU Bing SHEN Meng NING PetroChina Research Institute of Petroleum Exploration and Development Beijing100083China Institute of Energy China University of GeosciencesBeijing100083China School of Earth and Space Sciences Peking UniversityBeijing100871China

Dolomite genesis is a century-old mystery in *** reveal the mechanism of dolomite genesis,two core problems need to be *** first is the origin and migration mechanism of Mg^(2+)-rich fluids during the dolomitization *** second is the kinetic barrier caused by Mg^(2+)hydration during dolomite precipitation at low *** address these problems,our study,based on detailed petrological,sedimentological,geochemical(major and trace elements),and isotopic(C-O-Mg)analysis,clarified the source and migration of Mg^(2+)-rich fluids and the kinetic barrier mechanism of lowtemperature dolomite precipitation in the Upper Sinian Qigebulake Formation and the Lower Cambrian Xiaoerbulake Formation in the Tarim ***,we found that the Mg^(2+)-rich fluids required for the dolomitization of dolomite in the Xiaoerbulake Formation were primarily derived from the Early Cambrian marine *** the interface of the sedimentary cycle,δ26Mg values fluctuated considerably,indicating that the sequence interface was the starting point and channel for the migration of dolomitized *** level variation plays a major role in controlling the dolomitization process of the Xiaoerbulake ***,the Qigebulake Formation contains low-temperature dolomite with Mg^(2+)-rich fluids supplied by seawater,microorganisms,and sedimentary organic *** analysis shows that the dolomite of the Qigebulake Formation was formed by microbial induction by anaerobic methane ***,the properties and sources of dolomitization fluids and the formation process of dolomite were the reasons for the difference in the Mg isotope composition of dolomite during the Sinian-Cambrian *** study reveals the genetic mechanism of the Sinian-Cambrian dolomite in the Tarim Basin and establishes a new method to explain the genesis of microbial dolomite by C-O-Mg isotopes,providing a reference for the reconstruction of the formation and evolutio

关键词： Dolomite genesis Mg isotopes carbon and oxygen isotopes Xiaoerbulake Formation Qigebulake Formation Tarim Basin

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Petrology and geochemistry of cold seep carbonates from the northern Okinawa Trough,East China Sea:implications to early diagenesis

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Journal of Oceanology and Limnology 2022年第4期40卷 1388-1403页

作者： Kehong YANG Zhimin ZHU Yanhui DONG Weiyan ZHANG Fengyou CHU Key Laboratory of Submarine Geosciences&Second Institute of Oceanography Ministry of Natural ResourcesHangzhou 310012China

carbonate samples were collected from the northern Okinawa Trough in the East China Sea in *** petrology,mineralogy,carbon and oxygen isotopes,and rare earth elements(REEs)of these samples were ***,high-Mg calcite,and dolomite were the main carbonate minerals,the contents of which varied greatly among the carbonate *** observations revealed the common occurrence of framboidal ***δ^(13)C values of carbonates varied from-53.7‰to-39.3‰(average of-47.3‰based on Vienna Pee Dee Belemnite(V-PDB),n=9),and theδ^(18)O values ranged from 0.6‰to 3.4‰(average of 1.9‰;V-PDB,n=9).The carbon and oxygen isotope characteristics indicated that the carbonates precipitated during the anaerobic oxidation of *** carbon source was a mixture of thermogenic methane and biogenic methane,possibly with a greater contribution from the *** oxygen isotope data showed that gas hydrate dissociation occurred during carbonate *** Ce anomalies suggested that the carbonates precipitated in an anoxic environment.A slight enrichment of middle REEs(MREEs)could be attributable to the early *** structures,minerals,oxygen isotopes,and MREEs all indicated that the carbonates experienced some degree of early ***,the infl uence of early diagenesis should be considered when using geological and geochemical proxies to reconstruct original methane seepage environments.

关键词： authigenic carbonate carbon and oxygen isotopes rare earth elements(REEs) anaerobic oxidation of methane(AOM) northern Okinawa Trough

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Genesis of Qujiashan manganese deposit, Shaanxi Province: constraints from geological, geochemical, and carbon and oxygen isotopic evidences

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Journal of Central South University 2019年第12期26卷 3516-3533页

作者： WANG Zi-yong HAN Run-sheng REN Tao WU Yong-tao LI Hu-jie Faculty of Land Resource Engineering Kunming University of Science and TechnologyKunming 650093China College of Environment and Resource Southwest University of Science and TechnologyMianyang 621010China

The Qujiashan manganese deposit is located in the Longmen-Daba fold belt along the northern margin of the Yangtze Block. The layered ore bodies are distributed within the purple-red calcareous shale. Qujiashan is a high-grade w(MnO)=8.92% to 18.76%) manganese deposit with low-phosphorus w(P2O5)=0.08% to 0.16%) content. It also has a low total REEs contents(with an average of 101.3×10-6), and has inconspicuous Ce(0.81 to 1.29) and Eu(1.00 to 1.25) anomalies. lg(Ce/Ce*) values are from-0.02 to 0.11. The ores have high SiO2/Al2O3 and Al/(Al + Fe + Mn) ratios. In figures of Fe–Mn–[(Ni+Cu+Co)×10] and lgU–lgTh, all samples show that hydrothermal exhalative fluids played an important role during mineralisation. The δ13CPDB and δ18OSMOW values of eight ore samples are from-20.7‰ to-8.2‰(with an average of-12.4‰) and from 14.3‰ to 18.7‰(with an average of 17.0‰), respectively. These carbon and oxygen isotopic features indicate that hydrothermal fluids derived from deep earth are participation in the metallogenic process, which is also supported by high paleo-seawater temperatures varying from 47.08 to 73.98 °C. Therefore, the geological and geochemical evidences show that the Qujiashan deposit formed from submarine exhalative hydrothermal sedimentation.

关键词： manganese deposit element geochemistry carbon and oxygen isotopes genesis Qujiashan manganese deposit

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carbon and oxygen isotope characteristics of foraminiferan from northern South China Sea sediments and their significance to late Quaternary hydrate decomposition

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Journal of Central South University 2012年第6期19卷 1728-1740页

作者：雷怀彦曹超欧文佳龚楚君史春潇 State Key Laboratory of Marine Environment Science(Xiamen University) Third Institute of Oceanography State Oceanic Administration

carbon and oxygen isotope and dating analyses of foraminiferan in sediment cores collected from three different areas of the northern slope of the South China Sea were conducted, in order to examine the records of the gas hydrate decomposition events since the late Quaternary under the conditions of methane seepage. The results show that： 1） the δ13C values of the benthic foraminiferan Uvigerina spp. （size range of 0.25-0.35 ram） are from -0.212% to -0.021% and the δ180 values of the planktonic foraminiferan Globigerinoides ruber （size range of 0.25-0.35 ram） are from -0.311% to -0.060%; 2） three cores （ZD2, ZD3 and ZS5） from the bottom of a hole are aged for 11 814, 26 616 and 64 090 a corresponding to the early oxygen isotope stage （MIS） Ⅰ, Ⅲ and Ⅳ final period, respectively; 3） a negative-skewed layer of carbon isotope corresponds to that of MIS II （cold period）, whose degree of negative bias is -0.2%0; and 4） the δ13C compositions of foraminiferans are similar to those of the Blake Ridge and the Gulf of Mexico sediments of the late Quaternary. According to the analysis, the reasons for these results are that the studied area is a typical area of methane seep environment in the area during MIS II due to the global sea-level fall and sea pressure decrease. Gas hydrate is decomposed and released, and a large number of light carbon isotopes of methane are released into the ocean, dissolved to inorganic carbon （DIC） pool and recorded in the foraminiferan shells. A pyrite layer developed in the negative bias layers of the foraminiferans confirms that the δ13C of foraminiferans is more affected by methane and less by the reduction of marine productivity and early diagenesis. The use of foraminiferan δ13C could accurately determine late Quaternary hydrate release events and provide evidence for both reconstructing the geological history of methane release events and exploring natural gas hydrate.

关键词： northern South China Sea foraminiferan carbon and oxygen isotopes natural gas hydrate

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Morphology and features of Cambrian oncoids and responses to palaeogeography of the North China Platform

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Journal of Palaeogeography 2020年第2期9卷 150-167页

作者： En-Zhao Xiao Ming-Xiang Mei Shu Jiang Tehseen Zafar School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing 100083China Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education and Faculty of Earth Resources China University of Geosciences(Wuhan)Wuhan 430074China Institute of Geochemistry Chinese Academy of SciencesGuiyang 550081China Institute of Geology University of the PunjabLahore 54590Pakistan

The Cambrian strata in the North China Platform are fully exposed. A wide variety of carbonate oncoids with different shapes occur in the Xuzhuang and Zhangxia formations(Miaolingian Series) from six Cambrian sections in the study area. A comprehensive study involving outcrop description, microscopic observation, scanning electron microscopy(SEM), energy dispersive X-ray spectroscopy(EDX), X-ray diffraction(XRD), and carbon and oxygen isotope analysis is conducted to determine the facies, morphology, internal structure, and geochemical properties of the oncoids. The oncoids are divided into six types based on their morphology and internal *** and ultrastructural observations reveal typical microbial fossils(Girvanella) and microbially-related sediments(framboidal pyrite), indicating the biogenicity of the oncoids. Additionally, the XRD and carbon and oxygen isotope analysis results suggest that the formational environments of these oncoids are different due to terrestrial influences. Statistical data on the oncoids from the six sections show that there are obvious differences in the types of oncoids and the proportions of different varieties in each section. The spatial differences in the oncoid morphologies are associated with different palaeogeographic settings. The rough oncoid growth patterns developed in nearshore environments were influenced by terrigenous debris and steep terrain, whereas the delicate oncoid growth patterns developed in offshore environments were less affected by terrestrial factors and were featured by more stable depositional processes related to microbial mats.

关键词： Morphological classification Microbial m at Girvonello carbon and oxygen isotopes Miaolingian series North China

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The bio-barite in witherite deposits from Southern Qinling and its significance

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Progress in Natural Science:Materials International 2004年第10期14卷 49-55+98页

作者： Lv Zhicheng 1,2 ,LIU Congqiang 2 ,LIU Jiajun 2 and WU Fengchang 2 (1.Development and Research Center,China Geological Survey,Beijing100037,China 2.Institute of Geochemistry,Chinese Acade-my of Sciences,Guiyang550002,China) China Geol Survey Ctr Res & Dev Beijing 100037 Peoples R China Chinese Acad Sci Inst Geochem Guiyang 550002 Peoples R China

Being stratiform or stratoid,the Huangboshuwan witherite deposit at Zhiyang and the Wenyuhe witherite-barite deposit at Zhushan occur in the lower Lower Cambrian siliceous rocks and the orebodies are remarkably controlled by lithological character and *** and oxygen isotopic studies of witherite,barytocalcite and calcite have shown that the carbon,involved in the formation of these minerals,was derived largely from organic carbon resultant from degradation,polycondensation and dehydroxylation of bio-organic matter in sediments at the early stage of *** occurrence of bio-barite strongly evidenced that Ba 2+ was concentrated and settled down in the form of bio-barite on the seafloor as a result of biological processes,thereafter forming the initially enriched orebodies of barium *** witherite was metasomatic products of bio-barite under the action of sulfate-reducing bacteria and organic and inor-ganic reduction.

关键词： bio-barite carbon and oxygen isotopes early diagenesis witherite deposits

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Geological Characteristics and Manifestations of Geological Processes of Sequence Boundaries and Their Vicinities

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Acta Geologica Sinica(English Edition) 1997年第4期71卷 386-394页

作者： Xiao Linping Testing Centre of Geotechnical Engineering, Southwest Jiaotong Universityand Zhao YuguangChengdu Institute of Mineral Resources, Chinese Academy of Geological Sciences, Chengdu, Sichuan, 610082 Liu Xinzhu

This paper discusses the geological characteristics and architectures of sequence boundaries and their vicinities and has proposed a classification scheme for the sequence boundaries, which can thus be grouped into three types and eight categories: type I includes exposed truncated surface, palaeosol surface, palaeokarst surface and exposed surface; type Ⅱ boundaries include structural transitional surface during sea-level fall and transgressive onlap surface; and type Ⅲ includes submarine erosional diagenetic diastem and event surface. A study has been made for the three major boundaries lying between the Permian and pre-Permian, the Permian and Triassic, and the Middle and Lower Triassic respectively in terms of multiple disciplines such as lithostratigraphy, biostratigraphy, magnetostratigraphy and carbon and oxygen isotopic geology. These three boundaries are ascribed to type I , typeⅡ and typeⅢ, respectively.

关键词： sequence boundaries architectural analysis biotic succession magnetopolarity superperiod carbon and oxygen isotopes

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Characteristics and Implications Significance for carbon and oxygen Isotope Continuous Change of Zhenjia1 Well in The Northern Shaanxi Salt Basin

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Acta Geologica Sinica(English Edition) 2014年第S1期88卷 269-271页

作者： XING Enyuan ZHANG Yongsheng ZHENG Mianping WANG Zhuozhuo PAN Wei ZHAI Daxing WU Feimeng MLR Key Laboratory of Saline Lake Resources and Environments Institute of Mineral ResourcesCAGS

Zhenjia1 well located in the 2nd salt depression of the Northern Shaanxi Salt Basin(Zhang et al,2013),is the basis potash exploration wells,and its main purpose is marine potash prospection,combining with gas *** comp... 详细信息

关键词： carbon and oxygen isotopes ancient marine environments Ordovician Zhenjia1well

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