Forced regression and its sedimentary response to continental lacustrine rift basin: A case of the Member 3 of Shahejie Formation in Laizhouwan sag,Bohai Bay Basin          下载免费PDF全文

Qin Yi  Zhu Xiao-Min  Wang Tong  Guo Cheng  Xie Shuang-Hui 《古地理学报》1999,22(3):457-468

Falling stage systems tract(FSST)is an offlap strata with strong relationship with hydrocarbon exploration,which is driven by relative lake-level fall and developed above the highstand systems tract and below the lowstand systems tract of a new sequence. It has no relationship with sediment supply. Based on the theory of sequence stratigraphy and sedimentology,3D seismic data,drilling core data,and well-logging data were comprehensively analyzed. The study showed that the FSST strata was formed in the Member 3 of Shahejie Formation in the Laizhouwan sag. The FSST can be divided into three units,namely as units P1,P2,and P3 from bottom to top. The P1 is the first unit of progradation downlap the bottom of the FSST. The top of the unit P3 is a sequence boundary exhibits subaerial unconformity. The seismic profile along the source direction is characterized by the low-angle oblique progradation reflection that downstream the center of lake basin from west to east. Incised valleys developed on the top of the FSST perpendicular to the source direction. Gamma-ray logging response is manifested by a series of funnel-shaped complex,indicating that the sedimentary response of the FSST was a cycle of coarsening-upward parasequence sets. Comprehensive studies on core interpretation and well-logging analysis showed that the FSST was a fluvial-delta sedimentary system with slumped fan deposits associated with the delta front. Consequently,the FSST is a common result of relative dry climate and falling of lake level,considering regional tectonic evolution,sediment supply,and paleo-climate change. The discovery of the FSST in the Laizhouwan sag has an important geological significance for the sedimentological interpretation,and it offers a guidance for further oil exploration in the study area. In addition,it also serves as a significant reference for future research on the FSST development and exploration in the continental lacustrine rift basin.  相似文献   

Coupling between metallogenesis of the Cryogenian Datangpo-type manganese deposit in South China and major geological events          下载免费PDF全文

Yu Wen-Chao  Du Yuan-Sheng  Zhou Qi  Wang Ping  Qi Liang  Xu Yuan  Jin Song  Pan Wen  Yuan Liang-Jun  Xie Xiao-Feng  Yang Bing-Nan 《古地理学报》1999,22(5):855-871

The exploration of the Cryogenian manganese deposits in the Datangpo Formation of South China has achieved great progress in recent years. It is concern in the long term there are many studies on this manganese deposits due to its particularity in the temporal and spatial distribution and the mineralization background. In this paper,we systematically summarize the previous achievements on the Datangpo-type manganese deposits. Besides,we also review current findings of Neoproterozoic global geotectonics,palaeoclimate evolution,ancient marine chemistry,and microbial evolution etc. The possible linkage between the massive metallogenesis of the Cryogenian Datangpo manganese deposits in the South China and Neoproterozoic major geological events is established. The break-up of Rodinia supercontinent led to the widespread rift basin systems in the world since the Middle Neoproterozoic. The Nanhua Basin in South China,which is a manganese-forming sedimentary basin,developed from the rift basin. The rift basin provided space for manganese deposits and controlled the distribution of manganese deposit. The hydrothermal activities at the bottom of the basin provided favorable manganese source. During the Neoproterozoic ice period(“Snowball Earth”event),global ice-sheets cut off or hindered exchanges of mass and energy between different spheres of Earth,which may lead to the widespread anoxic condition in the ice age ocean. The palaeoclimate changes during the glacial-interglacial period led to the disappearance of ice-sheets and the triggering of mass and energy exchanges between different sub-systems of Earth,followed by the variation of redox condition of the ancient sea. For the Nanhua Basin,the oxidation of surface water and the oxygen-bearing base flow provided the oxidation environment for the precipitation of manganese. Besides,new evidence indicated that manganese microbiological mineralization was the potential mechanism for manganese deposit under the microbial resuscitation condition during the interglacial period. All these major geological events have complicated connections and they provided essential metallogenic conditions for the sedimentary mineralization of “Datangpo”manganese deposit. It is believed that there is a coupling between the sedimentary metallogenesis of the Cryogenian Datangpo-type manganese deposit in South China and Neoproterozoic major geological events.  相似文献   

APPLICATION OF STATISTICAL INTERPRETATION TECHNIQUES WITH NWP PRODUCTS FOR OBJECTIVE FORECASTING OF TROPICAL CYCLONE MOTION     

钟元 《热带气象学报(英文版)》1999,5(1):67-75

Statistical study is first performed of the efficiency of the technique of statistical interpretation using the products of NWP. The result shows that the application of the technique has improved the predictabilily of predictors in objective forecasting of tropical cyclone motion, increased the forecasting skill of models and extended the valid period of forecast. Then a discussion is made of some technical problems in the application in the motion forecasting, suggesting: a large sample of data and perfect forecast method be employed in constructing objective forecast models for tropical cyclone motion, predictors be included that are so finely built that they reflect all synoptic features and physical quantity fields and NWP products be used and corrected that are available at multiple times. It is one of the effective ways to improve the skill and stability of the forecast by composite use of outcomes from various forecasting models.  相似文献   

基本气流在局域流型演化过程中的作用   总被引：3，自引：0，他引：3  

罗哲贤  谢金南  马镜娴 《大气科学》1999,23(3):308-315

用一个β平面准地转正压模式,实施了5组时间积分为72个模式日的试验,分析了不同基本气流对局域流型演化特征的作用。结果指出:强的基本气流相应于持续性干旱流型;弱的基本气流相应于间歇性的干旱流型。  相似文献   

一种新的统计回归模型及其建模方案   总被引：3，自引：0，他引：3  

陶云  曹杰  严华生  谢应齐 《大气科学》1999,23(3):333-339

根据经典门限自回归模型的基本思想,引入半截多项式变换,导出了一种新的统计回归模型,并提出了相应的一整套建模方案。这种模型和建模方案的特点是:（1）解决了统计回归分析中逐段线性化模型的检验问题;（2）在确定统计回归模型中各待估参数和变量——包括门限变量、门限值、阶数、时滞和回归系数时显得十分方便、快捷。试验结果表明,根据此方案建立的统计回归模型具有较高的拟合和预报精度,同时具有良好的稳定性。  相似文献   

华北和北京的酷暑天气 Ⅱ. 模拟实验和机理分析   总被引：1，自引：0，他引：1  

孙建华  陈红  赵思雄  曾庆存  谢庄  崔继良  刘海涛 《气候与环境研究》1999,4(4):334-345

利用Ｐｅｎｎ／ＮＣＡＲ 的ＭＭ５ 中尺度模式对１９９９ 年６ 、７ 月华北的两段高温过程进行了模拟研究, 并利用模拟输出量对高温形成的机理进行了一些探讨。结果表明, 在利用了Ｎｕｄｇｉｎｇ 同化以后, 中尺度模式能对整个过程作较长时间的模拟, 对高压的移动过程、强度和维持能较好的复制出来。分析结果表明, 大陆副热带高压中的下沉增温和辐射增温是造成此高温酷暑天气的主要原因。  相似文献   

江西"98.6"连续大暴雨过程云场特征分析   总被引：2，自引：0，他引：2  

李玉芳  谢基平 《气象与减灾研究》1999,22(2):17-19

分析暴雨过程中各个阶段的云场变化情况．并结合中、小尺度系统分析部分云型与流场的对应关系。  相似文献   

Retrogressive Microstructures:A Key to Post Collisional Uplift and Extension Tectonics of Ultrahigh-Pressure Metamorphic Rocks from Dabie Orogenic Belt,China     

You Zhendong  Suo Shutian  Zhong Zengqiu  Zhang Zeming  Wei Bize 《中国地质大学学报(英文版)》1999,10(3):200-206

ThereisanunanimousunderstandingthattheUHPmetamorphisminDabie-SuluareaswasformedduringtheTri-assiccollisioneventbetweentheYangtzeandNorthChinacratons(Congetal.,l994$Zhouetal-,l996;Liouetal.,l994)-Eclogiteisthemostimportantrocktypeamongtheul-trahigh-pressure(UHP)metamorphicrocks.Accordingtotheiroccurrencethereare3typesofeclogites:typeIisen-clavesinultramaficintrusionsandasmembersinthelayeredmafic-ultramaficcomplex(Jahnl998);typeIispodsorlay-ersinthehighlymetamorphicsupracrustals(mainlying…  相似文献   

Multi-Layered Low-Angle Ductile Detachment System in Dabie-Sulu UHPM and HPM Belts,China     

Suo Shutian 《中国地质大学学报(英文版)》1999,10(3):187-193

INTRODUCTIoNTheDabie-Suluregion,Chinahasbeenrecognizedasthelargestultrahigh-pressuremetamorphic(UHPM)(peakp>2.7GPa)andHPMbeltsintheworld,andattractedexten-siveinterestfrominternationalgeoscientists.AwealthofpublicationsexistsabouttheoccurrenceofUHPMindexmin-erals,thegeochronology,metamorphicPTpaths,andthelarge-scaleconceptualtectonicevolutionofUHPMandhigh-pressuremetamorphic(HPM)rocksintheDabie-Suluregion.Morerecentoverviewsaregiven'byErnstetal.(1995),Liouetal.(l996),andHackere…  相似文献   

Late Permian Sequence Stratigraphic Framework and Controlling Factors in Southern Yangtze Platform and Its Margin     

Li Sitian  Lu Yongchao  Yan Jiaxin  Chen Beiyue  Xie Xinong 《中国地质大学学报(英文版)》1999,10(2):153-160

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