检索结果-南通市图书馆

Typical basin-fill sequences and basin migration in Yanshan,North china——Response to Mesozoic tectonic transition

在线全文

学校读者我要写书评

暂无评论

Typical basin-fill sequences and basin migration in Yanshan,...

中国科学院地质与地球物理研究所2.04学术年会

作者： li zhong~1,liu {2.~2.ZHANG {2.~2.& wang qingchen~1 1.institute of geology and geophysics,Chinese Academy of Sciences,beijing 10002.,china 2.china University of Geosciences,beijing 100083,china

Basin-fill sequences of Mesozoic typical basins in the Yanshan area,North china may be divided into four phases,reflecting lithosphere tectonic evolution from flexure(T),flexure with weak rifting(J),tectonic transition(J),and rifting(K).Except the first phase,the other three phases all start with lava and volcaniclastic rocks,and end with thick coarse clastic rocks and/or conglomerates,showing cyclic basin development rather than simple cyclic rift mechanism and disciplinary basin-stress change from extension to compression in each *** basin analysis,based on basin-fill sequences,paleocurrent distribution and depositional systems,shows that single basin-strike and structural-line direction controlling basin development had evidently changed from east-west to northeast in Late Jurassic in the Yanshan area, although basin group still occurred in east-west zonal *** Early Cretaceous,main structural-line strike controlling basins just turned to northeast by north in the studied area.

关键词： Yanshan Mesozoic basin-fill paleocurrent tectonic transition

Jurassic depositional records and sandstone provenances in Hefei Basin,central china:Implication for Dabie orogenesis

在线全文

cnki会议

学校读者我要写书评

暂无评论

Jurassic depositional records and sandstone provenances in H...

中国科学院地质与地球物理研究所2.04学术年会

作者： zhong li,~* Renwei li,Shu Sun and qingchen {2. institute of geology and geophysics,Chinese Academy of Sciences,beijing 10002.,china

Detrital composition and major element geochemistry of Jurassic sandstones in the south Hefei Basin,central china,show their provenance to be the Dabie Mountains, whose tectonic attributes are closely related to continent-island arc *** was found that a provenance change,from recycled orogen signatures and mixed orogenic sandstones to arc orogen,occurs from the lower Middle Jurassic to the Upper Jurassic (the Zhougongshan Formation).Dissected magmatic arc sources were gradually exposed in the Dabie Mountains due to intensive exhumation during the Late Jurassic,particularly after the Fenghuangtai depositional ***,it can be infered that the magmatic arc was initially present in both the Early Paleozoic and the Triassic,according to isotopic dating studies in previously published reports.δC-δO tracing between existing marbles of different strata in the Dabie block and marble gravels of the Fenghuangtai Formation in the Hefei Basin indicate that partial lithostratigraphic units for the Jurassic provenances have entirely disappeared from the Dabie block;therefore,it is impossible to reconstruct integral orogenic processes from studies on the remaining Dabie block alone. These findings,together with basin-fill sequences,also suggest that the Hefei Basin was mainly subjected to compressive mechanical regimes rather than extensional regimes in the Jurassic,which resulted in reverse-grading clastic depositional sequences,and is probably related to the northward intracontinental deep subduction of the Yangtze Plate. Regional exhumation properties and a tectonic model of the Late Mesozoic Dabie orogenesis are discussed in this paper.

关键词： basin-fill sequence Dabie Mountains Hefei Basin Mesozoic sandstone provenance

Magnetostratigraphic study of Cretaceous depositional succession in the northern Kuqa Depression,Northwest china

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2006年第1期51卷 97-107页

作者： PENG Shoutao li zhong HUANG Baochun liu Tao {2. {2. State Key Laboratory of lithospheric Evolution Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Division of the Earth's Deep Structure and Process Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China beijing institute of {2. for Mineral Resources Beijing 100012 China

There are some quite different disputes about chronostratigraphic division of the Cretaceous in the Kuqa Depression, northern margin of the Tarim Basin. We then carried on a magnetostratigraphic study on Cretaceous succession in the Kuqa River and Kezilenuer Channel profiles. Detailed paleomag- netic analyses on 446 specimens from 2.5 sites permit a construction of a preliminary magnetic polar- ity sequence for the Cretaceous strata. Together with paleobiologic constraints from calcareous nannofos- sils, magnetostratigraphic results show that the Bash- enjiqike Formation was probably deposited during the late Campanian to Maastrichtian stages of the Late Cretaceous, ranging from about 79.1 to 65.6 Ma. On the other hand, magnetozones identified from the Yageliemu, Shushanhe, and Baxigai formations may principally correlate with chrons M18r to M3 of the Geomagnetic Polarity Time Scale (GPTS). This cor- relation suggests that these three formations were very likely to be formed during the early-middle stage of the Early Cretaceous between the Berriasian to the early Berremian stages (141.9―12..1Ma). Therefore it is possible that the Bashenjiqike Formation con- tacts the underlying strata with an unconformity and there is a giant sedimentary hiatus during the period of the late Barremian to early Maastrichtian stages in the Kuqa Depression.

关键词：白垩纪低气压磁地层学沉积演化西北地区

Magnetostratigraphic study of Cretaceous depositional succession in the northern Kuqa Depression,Northwest china

在线全文

学校读者我要写书评

暂无评论

Magnetostratigraphic study of Cretaceous depositional succes...

中国科学院地质与地球物理研究所2.06学术年会

作者： PENG Shoutao~1,li zhong~1,HUANG Baochun~2.liu Tao~3 & {2. {2.~1 1.State Key Laboratory of lithospheric Evolution,institute of geology and geophysics,Chinese Academy of Sciences,beijing 10002.,china 2.Division of the Earth’s Deep Structure and Process,institute of geology and geophysics,Chinese Academy of Sciences,beijing 10002.,china 3.beijing institute of geology for Mineral Resources,beijing 100012.china

There are some quite different disputes about chronostratigraphic division of the Cretaceous in the Kuqa Depression,northern margin of the Tarim *** then carried on a magnetostratigraphic study on Cretaceous succession in the Kuqa River and Kezilenuer Channel *** paleomagnetic analyses on 446 specimens from 2.5 sites permit a construction of a preliminary magnetic polarity sequence for the Cretaceous *** with paleobiologic constraints from calcareous nannofossils,magnetostratigraphic results show that the Bashenjiqike Formation was probably deposited during the late Campanian to Maastrichtian stages of the Late Cretaceous,ranging from about 79.1 to 65 6 *** the other hand,magnetozones identified from the Yageliemu,Shushanhe,and Baxigai formations may principally correlate with chrons M18r to M3 of the Geomagnetic Polarity Time Scale(GPTS).This correlation suggests that these three formations were very likely to be formed during the early-middle stage of the Early Cretaceous between the Berriasian to the early Berremian stages(141.9-12..1 Ma).Therefore it is possible that the Bashenjiqike Formation contacts the underlying strata with an unconformity and there is a giant sedimentary hiatus during the period of the late Barremian to early Maastrichtian stages in the Kuqa Depression.

关键词： Kuqa Depression Cretaceous magnetostratigraphy

Eclogites preserved as pebbles in Jurassic conglomerate,Dabie Mountains,china

在线全文

cnki会议

学校读者我要写书评

暂无评论

Eclogites preserved as pebbles in Jurassic conglomerate,Dabi...

中国科学院地质与地球物理研究所2.03学术年会

作者： qingchen wang~(a,*),Renwei {2.~a,Daoxuan wang~b,Shuangying {2.~b a Laboratory of {2.thosphere Tectonic Evolution.institute of geology and geophysics.Chinese Academy of Sciences,beijing 10002.,china b Hefei University of Technology,Hefei 2.0009,china

Two types of eclogite pebbles were discovered in Midcle to Upper Jurassic conglomerates from the Hefei Basin north of the Dabie ultrahigh-pressure(UHP) terrain,*** A eclogite pebbles are characterized by idioblastic garnet with well preserved chemical *** content in phengite is lower than 3.5 per formula unit(pfu).The maximum metamorphic pressure is lower than 2.5 GPa,and the temperature is below 600℃.Type B eclogite pebbles contain coesite pseudomorphs in xenoblastic *** content in phengite is higher than 3.5 *** maximum metamorphic pressure is 2.8-4.0 GPa at 700℃indicating UHP metamorphism. Types A and B eclogite pebbles are comparable with eclogites occurring in the southern portion of the Dabie UHP terrain. Based on the petrologic similarities and northeastwards directed *** infer that the eclogite pebbles were eroded from the Dabie UHP *** containing detrital phengite with Si content higher than 3.5 pfu are also derived from UHP *** petrologic and stratigraphic data place lime constraints on exhumation and erosion history of the Dabie UHP terrain.

关键词： Eclogite pebble Jurassic conglomerate Hefei Basin:Dabie UHP terrain Exhumation

Rutile U-Pb age for the ultra-high pressure eclogite from the Dabie Mountains, central china: Evidence for rapid cooling

在线全文

cnki会议

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2002年第1期47卷 62-65页

作者： li Qiuli li Shuguang ZHOU Hongying li Huimin HONG Ji’an wang qingchen H.J.Massonne Department of Earth and Space Science University of Science and Technology of ChinaHefei 230026China Tianjin institute of geology and Mineral Resources Institule of geology and geophysics Chinese Academy of SciencesBeijing 100029China Institut fur Mineraloie&Kristallechemie Universitat StuttgartAzenbergster.1870174 StuttgartGermany

The U-Pb isotope compositions of rutile, om-phacite and garnet in the eclogite from the Jinheqiao area in the Southern Dabie ultrahigh-pressure metamorphic zonewere analyzed. The consistent high precision U-Pb age (2.8± 1.2. Ma of rutile in eclogite from the Dabie Mountains was obtained by two ways of isochron and common Pb correction based on the composition of omphacite. This proves that the omphacite in eclogite has a U/Pb ratio (μ = 2.8) low enough to be used for common Pb correction in the analyses of rutile. Under the rapid cooling condition (40℃/Ma) the closure temperature for U-Pb diffusion in rutile is about 470℃. Thus, this U-Pb age of rutile proves that 2.8 Ma should be the cooling age of eclogite at 470℃ instead of the peak meta-morphic age.

关键词： U-Pb dating of rutile eclogite Dabie Mountains.

我国空间环境天/地基监测平台的发展态势和展望

在线全文

学校读者我要写书评

暂无评论

航天器环境工程 2021年第3期38卷 225-239页

作者：王赤陈志青胡连欢胡泽骏薛向辉徐轻尘张贤国李发泉王威宗位国杜丽芳袁伟王一楠刘正宽丁宗华郝永强张清和罗冰显王喜珍龚晚林中国科学院国家空间科学中心北京100190 中国科学院地质与地球物理研究所北京100029 中国极地研究中心上海200136 中国科学技术大学地球与空间科学学院合肥230026 中国科学院精密测量科学与技术创新研究院武汉430071 中国科学院国家天文台北京100101 中国气象局国家卫星气象中心北京100081 中国科学院大气物理研究所北京100029 中国电波传播研究所青岛266107 北京大学地球与空间科学学院北京100871 山东大学空间科学与物理学院济南250100 中国地震局地球物理研究所北京100081 武汉大学电子信息学院武汉430072 中国科学院大学地球与行星科学学院北京100049

文章简要回顾我国空间环境天/地基监测设施的发展历程,重点阐述发展现状,并分析未来发展方向。目前,我国的空间环境天基监测已具备一定规模,覆盖主要的轨道类型,探测要素基本齐全,正在工程实施阶段的太阳风‒磁层相互作用全景成像卫星(SM... 详细信息

文章简要回顾我国空间环境天/地基监测设施的发展历程,重点阐述发展现状,并分析未来发展方向。目前,我国的空间环境天基监测已具备一定规模,覆盖主要的轨道类型,探测要素基本齐全,正在工程实施阶段的太阳风‒磁层相互作用全景成像卫星(SMILE)计划、空间先进太阳观测台(ASO-S)计划,以及规划中的日地拉格朗日L1点监测,将促进天基监测能力的大幅提升。地基监测方面,网络化综合监测能力快速发展,“子午工程”二期正在建设的覆盖全国和高/中/低纬的、日地空间全圈层的立体式监测网络将使我国地基监测能力步入世界先进行列。同时,国际子午圈大科学计划的有序推进标志着我国空间环境地基监测正迈出辐射全球的步伐。我国空间环境监测平台已经进入天/地基融合发展的新阶段。

关键词：空间环境监测天基监测地基监测空间天气