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SEDIMENTATION OF anoxic ENVIRONMENTS UNDER TRANSGRESSION AND UPWELLING PROCESS IN EARLY PERMIAN IN LOWER YANGTZE AREA

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Chinese Science Bulletin 1990年第14期35卷 1193-1198页

作者：吕炳全瞿建忠 Marine Geology Department Tongji University Shanghai 200092 PRC

Ⅰ. INTRODUCTIONQixia（P11 q） and Gufeng（P12 g） formations of early Permian series were deposited during the maximum transgression periods in the upper Paleozoic. With a thickness of 150—200m, Qixia formation is composed of Liangshan coal seams ～1.5—3 m thick at the bottom, bitumen-bearing thickly-stratified 'stinking limestone' in the lower part, consisting of greyish-black biological clastic micrite and micro-silty limestone. The limestone in the

关键词： siliceous rock upwelling anoxic environment.

The influence of ganglioside on the blood gas analysis and serum inflammatory cytokines in newborns with anoxic ischemic encephalopathy

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Journal of Hainan Medical University 2017年第4期23卷 133-136页

作者： Xiao-Jing Li Hai-Xia Zhu Ying-Yan Gan Jian-Ning Mai Hui-Ci Liang Department of Neurology Women and Children's Medical CenterGuang DongGuang Zhou 510120

Objective:To observe the influence of ganglioside on the blood gas analysis and serum levels of inflammatory cytokines in newborns with anoxic ischemic ***: A total of 100 newborns with anoxic ischemic encephalopathy in our hospital were selected and randomly divided into 2 groups: the control group and the observation group. Conventional oxygen inhalation, reducing intracranial pressure, controlling eclampsia and neurotrophic drug treatment were given to the observation group. Treatment of ganglioside was given to the control group on the basis of observation group. Blood gas analysis and serum levels of inflammatory cytokines were detected before treatment (T0), 3 d after treatment (T1), and 7 d after treatment (T2).Result: (1) The comparison of pH, PaO2, PaCO2, SaO2 in the two groups in T0 was not statistically significant. The comparison of pH, PaO2, PaCO2, SaO2 in T0, T1, T2 was considered to be statistically significant. Among these, the result of comparision of pH, PaO2, SaO2: T0T1>T2. The pH, PaO2, SaO2 in observation group were higher, PaCO2 in observation group was lower compared with that in control group in T1 and T2. The difference was considered to be statistically significant. (2) The comparision of IL-2, IL-6, hs-CRP, TNF-α in the two groups in T0 was not statistically significant. IL-2 in the observation in T1 and T2 was higher than that in the control group, IL-6, hs-CRP, TNF-α in the observation in T1 and T2 was lower than that in the control group. The difference was considered to be statistically ***: Ganglioside can improve blood gas analysis indexes, decrease the serum inflammatory cytokines in newborns with anoxic ischemic encephalopathy.

关键词： Ganglioside Newborns with anoxic ischemic encephalopathy Blood gas analysis Inflammatory factor

Sulfur Isotopes of Framboidal Pyrite in the Permian-Triassic Boundary Clay at Meishan Section

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Acta Geologica Sinica(English Edition) 2011年第3期85卷 694-701页

作者： ZHANG Jun LIANG Handong HE Xiaoqing YANG Ye CHEN Baohua State Key Laboratory of Coal Resources andSafety Mining China University of Mining and Technology Beijing 100083 China Haihe River Water Environmental Monitoring Center Haihe River Water Conservancy Commission Ministry of Water Resources Tianjin 300170 China

Pyrite framboids were found in the Permian-Triassic boundary at Meishan Section,while their sulfur isotopes were *** majority of framboids is less than 5μm in diameter,with some large-sized ***,euhedral gypsums were observed in the boundary *** authors suppose that most of the pyrite framboids formed just below the redox boundary and stopped growing after entering the lower water *** result indicates that it was probably lower dysoxia condition in the temporal ***,the authors also presume that some pyrite was oxidated to sulfates accompanying the fluctuation of redox condition,which would probably be the origin of the negative sulfur isotopes of gypsum and CAS reported *** addition,sulfur isotope of framboidal pyrite suggests that sulfur is originated from bacterial sulfate reduction in anoxic ***, this study confirms that the ocean was widely anoxic during the Permian-Triassic transitional period. However,the redox condition in temporal ocean was probably not stable,with short-term fluctuations.

关键词： Permian-Triassic framboidal pyrite sulfur isotope anoxic Meishan

Seawater Temperature and Dissolved Oxygen over the Past 500 Million Years

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Journal of Earth Science 2019年第2期30卷 236-243页

作者： Haijun Song Paul B. Wignall Huyue Song Xu Dai Daoliang Chu State Key Laboratory of Biogeology and Environmental Geology School of Earth SciencesChina University of Geosciences School of Earth and Environment University of Leeds

Ocean temperature and dissolved oxygen concentrations are critical factors that control ocean productivity, carbon and nutrient cycles, and marine habitat. However, the evolution of these two factors in the geologic past are still unclear. Here, we use a new oxygen isotope database to establish the sea surface temperature(SST) curve in the past 500 million years. The database is composed of 22 796 oxygen isotope values of phosphatic and calcareous fossils. The result shows two prolonged cooling events happened in the Late Paleozoic and Late Cenozoic, coinciding with two major ice ages indicated by continental glaciation data, and seven global warming events that happened in the Late Cambrian, Silurian–Devonian transition, Late Devonian, Early Triassic, Toarcian, Late Cretaceous, and Paleocene–Eocene transition. The SSTs during these warming periods are about 5–30 °C higher than the present-day level. Oxygen contents of shallow seawater are calculated from temperature, salinity, and atmospheric oxygen. The results show that major dissolved oxygen valleys of surface seawater coincide with global warming events and ocean anoxic events. We propose that the combined effect of temperature and dissolved oxygen account for the long-term evolution of global oceanic redox state during the Phanerozoic.

关键词： sea surface temperature global warming ocean anoxic event dissolved oxygen Phanerozoic

Perspectives in Biological Nitrogen Fixation Research

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Journal of Integrative Plant Biology 2008年第7期50卷 786-798页

作者： Qi Cheng Department of Biochemistry Redox Biology Center University of Nebraska-Lincoln Lincoln Nebraska 68588 USA

Nitrogen fixation, along with photosynthesis is the basis of all life on earth. Current understanding suggests that no plant fixes its own nitrogen. Some plants （mainly legumes） fix nitrogen via symbiotic anaerobic microorganisms （mainly rhizobia）. The nature of biological nitrogen fixation is that the dinitrogenase catalyzes the reaction-splitting triple-bond inert atmospheric nitrogen （N2） into organic ammonia molecule （NH3）. All known nitrogenases are found to be prokaryotic, multi-complex and normally oxygen liable. Not surprisingly, the engineering of autonomous nitrogen-fixing plants would be a long-term effort because it requires the assembly of a complex enzyme and provision of anaerobic conditions. However, in the light of evolving protein catalysts, the anaerobic enzyme has almost certainly been replaced in many reactions by the more efficient and irreversible aerobic version that uses O2. On the other hand, nature has shown numerous examples of evolutionary convergence where an enzyme catalyzing a highly specific, O2-requiring reaction has an oxygen-independent counterpart, able to carry out the same reaction under anoxic conditions. In this review, I attempt to take the reader on a simplified journey from conventional nitrogenase complex to a possible simplified version of a yet to be discovered light-utilizing nitrogenase.

关键词： aerobic anaerobic anoxic convergent enzyme light-independent light-utilizing nitrogen fixation nitrogenase oxic protochlorophyllide reductase.

Biotic recovery from the Late Devonian F-F mass extinction event in China

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Science China Earth Sciences 2002年第4期45卷 380-384页

作者：廖卫华 1. Nanjing Institute of Geology and Paleontology Chinese Academy of Sciences 210008 Nanjing China

The Frasnian-Famennian (F-F) mass extinction is one of the five great extinctions of marine life during the Phanerozoic. The F-F event killed most of the Devonian reefs, the characteristic Devonian corals, stromatoporoids, bryozoans, nearly all tentaculites, a few superfamilies of brachiopods, such as Atrypacea and Pentameracea and some important elements of goniatites, such as Manticoceras.``The end-Frasnian was a phase of mass extinction. A large number of shelly benthos were killed by the F-F event. Early and middle Famennian was the survival interval. The marine faunas were very rare at that time. The late Famennian was the recovery interval. There appeared to have many new taxa in the Strunian stage. It lacked a radiation interval in Late Devonian Famennian because another event (the D-C mass extinction) happened at the Devonian-Carboniferous boundary.``Several causes for the F-F mass extinction have been proposed by some geologists, which have been grouped into two broad types, terrestrial and extraterrestrial. The former is related to sea level changes, climate changes and anoxic water event. The latter is linked with some forms of meteorite impact.``A large-scale eustatic change of sea level and black shales representing an anoxic environment has been invoked to explain one of the causes for the F-F mass extinction.

关键词： Late Devonian, mass extinction, biotic recovery, eustatic change of sea level, anoxic environment.

Trace and rare earth element geochemistry of the black and grey shales of the Calabar Flank, Southeastern Nigeria: constraints on the depositional environment and the degree of metal enrichment

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Acta Geochimica 2021年第3期40卷 312-324页

作者： Christopher Iorfa Adamu Benjamin Odey Omang Oluwaseye Peter Oyetade Otu Johnson Therese Ntonzi Nganje Department of Geology Faculty of Physical ScienceUniversity of CalabarCross River StateNigeria Department of Geology Faculty of ScienceUniversity of BeninEdo StateNigeria

This study focuses on the trace and rare earth elements(REE)geochemistry of the Nkporo and Ekenkpon Shales of the Calabar *** main aim is to infer their depositional environment and the degree of their metal *** shale samples were analyzed using inductively coupled plasma mass *** results indicated that the mean concentrations of K,Na,and Fe in Nkporo and Ekenkpon Shales are 1.45,0.4,and 4.17 wt%,and 1.11,0.44,and 5.42 wt%;*** Nkporo Shale is enriched with the following trace elements;P>Mn>Sr>Ba>Zn>Ce>Rb>Zr>V>Cr>Ni and depleted in the following trace elements;Ta>Ge>Sb>Bi>Cd>Ag>Te>In>*** the Ekenkpon Shale is enriched with the following trace elements;P>Mn>Ba>Sr>V>Ce>Zr>Rb>Cr>Zn>Ni and depleted in;Sb>Ge>Bi>Ag>Ce>Te>In>*** concentration of redox-sensitive elements such as V,Ni,Mo,U,Cu,Cr,Re,Cd,Sb,Ti,Mn,and their ratio V/Mo and U/Mo in the black and grey shale samples show different *** REE obtained from the Nkporo and Ekenkpon Shales were PAAS *** Nkporo Shale showed a slightly flat light rare-earth element(LREE),middle rare-earth element(MREE),and heavy rare earth element(HREE)pattern ***/Ce*ranges from 0.95 to 1.09 in Nkporo Shale and 0.67 to 1.40 in Ekenkpon *** Ekenkpon Shale showed a slight LREE,MREE enrichment,and depleted HREE *** Mn contents and U/Mo ratio in Nkporo and Ekenkpon Shales suggests a poor oxygen transitional *** V/Mo and V/(V+Ni)ratios indicated that the Nkporo shales were deposited in an anoxic to suboxic conditions and Ekenkpon shales were also deposited under an anoxic to suboxic *** V/Ni ratio indicated that the organic matter in the Nkporo shale is terrigenous while that of the Ekenkpon shales are both terrigenous and marine in origin.

关键词： Rare-earth elements(REE) Trace elements Calabar Flank Suboxic anoxic

Referential significance of sulfur isotopes and separation of S species in black shales of Southwest China

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Chinese Science Bulletin 1999年第17期44卷 1612-1616页

作者： Chaodong Wu Fangang Zeng Jiajin Lei Rui Zhao Peking Univ Dept Geol Beijing 100871 Peoples R China Chinese Acad Sci Inst Geol Beijing 100029 Peoples R China

The states of S species in black shales are very complex, such as organic sulfur, pyrite sulfur and sulphate sulfur. The mineral microtexture, sulfur content and sulfur isotope can indicate the formation conditions and diagenetic processes of the black shales. The S species are separated perfectly and the relation between the content, mineral microtexture and

关键词： S species sulfur isotope black shales anoxic environment.

SEA FLUX OF TRACE METALS IN SAANICH INLET

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Chinese Journal of Oceanology and Limnology 1989年第4期7卷 345-354页

作者：詹滨秋 Wong C.S Johnson K.W Institute of Oceanology Academia Sirica Qingdao Insititute of Ocean Sciences Canada

The sea fluxes of trace metals, POC, and settled material were studied in anoxic sea water, Saanich Inlet, B.C., Canada with sediment traps. This paper discusses the change of mass fluxes of sediment, trace metals and POC for various seasons and depths. The annual mean of settled material is 1.56 g.m-2 .a-1, 84.6 mg. m-2. a-1 for POC, 60.0 mg.m-2. a-1 for Cu, 16.5 mg.m-2.a-1 for Pb, 189 mg.m-2. a-1 for Zn, 2.20mg.m-2.a-1 for Cd,699 mg.m-2.a-1 for Fe,38.8 mg.m-2.-1 for Co, and 84.6 mg.m-2.a-1 for *** relations between the average fluxes of trace metals and POC, the fluxes of trace metals and settled matter, and the sea fluxes of trace metals and Fe are in linear progression. The resident times of elements as calculated from sea flux, are 1.1 a. for Cu, 0.014 a. for Pb, 0.50 a. for Zn, 3.8 a. for Cd, 0.16 a. for Fe, 0.39 a. for Co,and 1.14 a. for *** order of resident times is as follows: Pb-Fe-Co-Zn-Cu-Ni-Cd. The metal resident times in Saanich Inlet are shorter than the values estimated for the

关键词： settled anoxic resident dissolved shorter residence depths recycling manganese deviation