检索结果-南通市图书馆

Geochemical,mineralogical,and petrological analyses for the interpretation of the sedimentary environment of the middle-Late ordovician Majiagou Formation(northern China)as a tool for more effective gas exploration

引用

Petroleum Science 2022年第6期19卷 2519-2532页

作者： Jie Gao Da-Wei Lv A.J.(Tom) van Loon Dun Wu Shandong Provincial Key Laboratory of Depositional Mineralization and Sedimentary Minerals Shandong University of Science and TechnologyQingdaoShandong266590China Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and TechnologyShandong266071China College of Earth Science and Engineering Shandong University of Science and TechnologyShandong266590China Exploration Research Institute Anhui Provincial Bureau of Coal GeologyHefeiAnhui230088China

Core samples from the deeply buried ordovician Majiagou Formation below the Huainan Coalfield(E China) have been investigated for their carbonate types,major and trace elements(including rare earth elements) and C and O isotopes,The objective was to get a better insight into the possible occurrences of gas(and possibly oil) derived from Carboniferous coals.It was found that the carbonates are dolomites with strongly varying amounts of CaO and MgO.The low concentrations of SiO_(2),Al_(2)O_(3),and Fe_(2)O_(3)indicate deposition in a normal marine environment with little terrigenous input,The Na_(2)O/K_(2)O,Fe/Mn and Sr/Ba ratios,as well as the Ga values indicate mainly a marine salinity and a hot and humid climate.The slight depletion of Ce and Eu,the depletion of heavy rare earth elements(HREE) and the enrichment of light rare earth elements(LREE) indicate deposition in a reducing environment.It thus appears that the Majiagou Formation below the Huainan Coalfield closely resembles that in the eastern part of the Ordos Basin,where several gas reservoirs are present,so that the Majiagou Formation under the Huainan Coalfield represents a promising target for hydrocarbon exploration.

关键词： Majiagou Formation Middle ordovician Major-element analysis REE analysis Trace-element analysis Hydrocarbon exploration

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Paleoenvironment reconstruction of the Middle ordovician thick carbonate from western Ordos Basin, China

引用

Petroleum Science 2023年第1期20卷 48-59页

作者： Jia-Qi Yang Jun-Tao Zhang Zhi-Liang He Tao Zhang School of Energy Resources China University of GeosciencesBeijing100083China SINOPEC Exploration and Production Research Institute Beijing100083China China Petrochemical Corporation Ltd. Beijing100728China

Reconstructing paleoenvironments has long been considered a vital component for understanding the development and evolution of carbonate reservoirs.The Middle ordovician Period is considered the archetypical greenhouse interval,and also a critical period in biological evolution.The middle Darriwilian isotope carbon excursion has been observed in many areas of the world and may be related to the biological explosions caused by decreases in the temperature.The thick carbonate rocks in the fifth member of the Middle ordovician Majiagou Formation in the Dingbei area of the Ordos Basin were chosen as an example,based on the concentration of major,trace and rare earth elements as well as C,O and Sr isotopic analyses,the paleoenvironment was reconstructed.And its impact on natural gas exploration was analyzed.The results show that the seawater paleotemperature was 29℃,suboxicanoxic paleoredox conditions were observed,and the seawater paleosalinity was high.A large number of plankton in the biological explosion caused a rapid increase in the total organic carbon in carbonate rocks,which provided natural gas as supplemental source rocks.Affected by early meteoric water,the dissolution of gypsum laid the foundation for high-quality reservoirs,and the residual gypsum also further preserved natural gas.This study provides new data for the paleoenvironment and a theoretical basis for further natural gas exploration.

关键词： middle darriwilian isotope carbon excursion Paleoenvironment Natural gas exploration Middle ordovician Ordos basin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Petrogenesis and Tectonic Implications of Middle ordovician Ocean Island Basalts from the Chagantaolegai Ophiolitic Mélange in Junggar,NW China

引用

Acta Geologica Sinica(English Edition) 2021年第4期95卷 1099-1111页

作者： CHEN Jiafu LI Rongyan MA Haitao HAN Baofu LIU Junlai Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines Department of GeologyNortheastern UniversityShenyang 110819China Department of Earth Planetaryand Space SciencesUniversity of CaliforniaLos Angeles 90095USA Ministry of Education Key Laboratory of Orogenic Belts and Crustal Evolution School of Earth and Space SciencesPeking UniversityBeijing 100871China State Key Laboratory of Geological Process and Mineral Resources School of Earth Sciences and ResourcesChina University of Geosciences(Beijing)Beijing 100083China

Seamount accretion is one of the most significant accretionary orogenic processes in the Central Asian Orogenic Belt,but there are few paleo-seamounts reported from and debate on the tectonic evolution of the Junggar Ocean still exists.In this study,we present geochronological,mineralogical,geochemical and isotopic data for basalts from the Chagantaolegai ophiolitic mélanges in Junggar.Zircon U-Pb dating on one basalt yielded a weighted mean^(206)Pb/^(238)U age of 469±7 Ma,which suggests that it formed in the Middle ordovician.All rock samples belong to alkaline basalt and show similar geochemical characteristics,displaying high TiO_(2)(~3 wt%),(La/Yb)N(17.6–19.0),ΣREE(232–289 ppm)and enrichment in Nb and Ta,which implies an ocean island basalt(OIB)affinity.Based upon positiveεN d(t)(+4.16 to+4.23),ΔNb(0.20–0.22)and low initial^(87)Sr/^(86)Sr(0.70425 to 0.70452)and Zr/Nb(3.35–3.57),we suggest that the Chagantaolegai OIB samples were likely derived from a fertile mantle source related to plume.The OIB rock assemblage,chert and marble in the southern part of the Chagantaolegai ophiolitic mélange indicates that a Middle ordovician seamount was accreted to the Boshchekul-Chingiz arc due to the northward subduction of the Junggar-Balkhash Ocean.

关键词： ocean island basalt seamount Middle ordovician CAOB West Junggar

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Taxonomy,Zonation and Correlation of the Graptolite Fauna across the Lower/Middle ordovician Boundary Interval in the Yangtze Gorges Area,South China

引用

Acta Geologica Sinica(English Edition) 2013年第1期87卷 32-47,44-47+43页

作者： WANG Chuanshang WANG Xiaofeng CHEN Xiaohong LI Zhihong Wuhan Center of China Geological Survey

The graptolite fauna across the Lower and Middle ordovician boundary at the Huanghuachang GSSP section, Yichang and the Jianyangping section, Xingshan County is described. The taxonomy of the pendent didymograptids, the graptolite zonations across the base of Middle ordovician and their correlations are discussed in this paper. The two revised graptolite zones, the Didymograptellus bifidus Zone and the Azygograptus suecicus Zone, can be well correlated to their equivalents elsewhere in the world.

关键词： graptolite Huanghuachang section Middle ordovician

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Biostratigraphic and Chemostratigraphic Correlation for the Base of the Middle ordovician between Yichang and Western Zhejiang Areas,South China

引用

Acta Geologica Sinica(English Edition) 2011年第2期85卷 320-329页

作者： ZHANG Yuandong Axel MUNNECKE CHEN Xu CHENG Junfeng LIU Xiao State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Nanjing 210008 China GeoZentrum Nordbayern FG Palaoumwelt University Erlangen-Nuremberg D-91054 Erlangen Germany Research Institute of Petroleum Exploration and Development East China Company SINOPEC Nanjing 210011 China

The base of the Middle ordovician （i.e. Dapingian Stage） has been defined at the first appearance datum （FAD） of conodont Baltoniodus？ triangularis at Huanghuachang, Yichang, China,but the precise correlation of the boundary to regions of other facies remain to be resolved. Herein we review the biostratigraphy and chemostratigraphy of the Huanghuachang Global Standard Stratotype-Section and Point （GSSP） section, and present our latest stratigraphic work on the nearby Chenjiahe s ection in Yichang, and the Hengtang Quarry section, Jiangshan, Zhejiang, which is regarded as representative of slope facies. The conodont and graptolite biostratigraphy as well as chemostratigraphy of the Chenjiahe section indicate that the base of the Middle ordovician also falls within the graptolite Azygograptus suecicus Zone, and coincides with a high or maximum δ13C value within a minor positive carbon isotope excursion, suggesting that the base boundary can be readily recognized across the entire Yangtze Gorges area. The integrated graptolite and conodont biostratigraphy and chemostratigraphy of the Hengtang section, Jiangshan, indicates that the basal boundary probably falls within the graptolite lsograptus caduceus imitatus Zone that overlies the Azygograptus suecicus Zone, and coincides with a remarkable drop of δ13C. This difference indicates that a multi-disciplinary approach is critical to identify the base boundary in those regions where the Baltoniodus ？ triangularis is absent.

关键词： Graptolite biostratigraphy chemostratigraphy Middle ordovician slope facies South China

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A Middle ordovician reef complex on the carbonate ramp of the NW Tarim,NW China

A Middle Ordovician reef complex on the carbonate ramp of th...

引用

2015年全国沉积学大会

作者： Jianpo Wang Yue Li Yuanyuan Zhang Wuhan Center of Geological Survey Nanjing Institute of Geology and Palaeontology

ordovician carbonates are well outcropped along the Lianglitag Mountains with distance about 35 km in Bachu County, NW Tarim. It was an epicontinental sea closed to the northwest margin of the Central Tarim Uplift palaeogeographically. Darriwilian(upper Middle ordovician) Yijianfang Formation is about 70 meters in thickness completely composed of shallow marine limestones. Patch reefal and biostromal units constructed dominantly by Calathiμm from the middle member of the formation are respectively concentrated from northern and southern regions along the Lianglitag Mountains. Bigger patch reefs more than 10 m in thicknesses and 50 m in diameters are prevailed in the northern region. Some of them are stacked by smaller mounds inserted by bioclastic units. Reef-attached shelly fauna are diverse identified as elements such as trilobites, nautiluses, bivalves, brachiopods etc.. Dilapidated Calathiμm together with coarse organism fragments illustrate a high-energy belt. The sizes of patch reefs are gradually shrinkable to meters in thicknesses and weak relieves southward. Coeval autobiostrome formed by in situ Calathiμm frameworks baffling matrixes is only about 3 m in thickness at the southernmost section. Other shelly elements are quite low both in diversity and abundance herein. It was likely to be a calmer environment favorably of a back reef setting. Moreover, the sedimentary unit equivalent to the Yijianfang Formation is completely lacked toward the southern Mazatag Well Block, where was an oldland exposed above the sea-level during this time-interval. Therefore, such ecologicl, morphological and taphonomicdifferentiations of subfacies on the carbonate ramp enhances a reef complex with more turbulence leeward from the northern region and calmer back reef belt southward. The northern margin of the carbonate ramp further extends to the Yangjikan section of Kelpin County. The Darriwilian graptolitic black shales of the Sargan Formation were formed in typical stagnated basin. Disappearance of the reef complex was es

关键词： Calathiμm reef complex Yijianfang Formation Middle ordovician Tarim Block NW China

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Halysis Høeg,1932—An ancestral tabulate coral from the Ordos Basin,North China

引用

Journal of Palaeogeography 2020年第4期9卷 480-494页

作者： Li-Jing Zheng Hong-Xia Jiang Ya-Sheng Wu Hong-Ping Bao Yue-Yang Zhang Jun-Feng Ren Zheng-Liang Huang Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China China United Coalbed Methane Corporation LTDBeijing 100011China Institute of Paleontology Hebei Geo UniversityShijiazhuang 050031Hebei ProvinceChina University of Chinese Academy of Sciences Beijing 100049China Research Institute of Petroleum Exploration and Development Changqing OilfieldXi'an 710021Shaanxi ProvinceChina

The problematic calcareous microfossil Halysis is abundant in the Middle ordovician Darriwilian Stage of the western edge of the Ordos Basin,North China.The rich and well-preserved specimens of Halysis in this area facilitate detailed studies for its skeletal construction and tube microstructure.Halysis differs from calcified cyanobacteria and calcareous red and green algae in morphology,skeletal construction and microstructure,as well as reproduction mode.Halysis typically consists of multiple juxtaposed parallel tubes arranged in sheets(‘multiple-tube'type)or is just composed of one tube(‘single-tube'type).In‘multiple-tube'Halysis,tube fission by bifurcation results from the insertion of a microcrystalline wall at the center of a mother tube.This study demonstrates for the first time that the tube walls of Halysis have a laminofibrous(fibronormal)microstructure,composed of fibrous calcite perpendicular to wall surface,and recognizes the‘single-tube'type Halysis composed of one tube;in addition,for the first time,this study finds out that‘multiple-tube'Halysis develops buddings from the conjunction of two tubes and‘single-tube'Halysis shows wide-angle Y-shaped branchings.Based on these findings,this study further compares Halysis with tabulate corals.Halysis appears stratigraphically earlier than Catenipora and Aulopora,and has a smaller tube size.‘Multiple-tube'Halysis resembles Catenipora and‘single-tube'Halysis resembles Aulopora in skeletal construction and microstructure,and in their tube walls of laminofibrous microstructure composed of fibrous calcite perpendicular to the tube wall surface.Catenipora and Halysis are both characterized by the absence of septal spines.The similarities suggest that Halysis may be the ancestor of Catenipora-like and Aulopora-like tabulate corals.

关键词： Halysis Morphology Taxonomic affinity Middle ordovician Tabulate coral Wuhai Inner Mongolia

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：