A Study on Sequence Stratigraphy of Mesoproterozoic and Neoproterozoic in Southern North China Platform

INTRODUCTIONThestrataofMesoprotCrozoicandNeoproterozoicaredevelopedcompletelyinthesouthpartoftheNorthetnaplatformandconsistofthreesystems,inasCendingorder,Jixiaulan,QingbaikouanandSlman.BasedonadetailedinvestigationontheolltcropandthecomprehenSiveanalysis,wediscussthecharaCterofsequencestratigraphyandthecorrelationoftheMemo--Neoproterozoicinthearea.FnThRrsor~unCrsANDPARA~unCrsMeSO--NooprotffezoicRadonalfortigraphyThesouthernpartofNorthChinaplatformherereferstotheareasincluding…     

Early Ordovician Sea Level Changes in South China and Their Worldwide Correlation

INTRODUCTIONTheoaf~ansed~arewidelydistributedinSouthetna,fromtheYanalCratondPborminnorthtocontinentalmarginofsoutheastern~insouth.ThePreSentpaperdiscussesmainlytheEarlyOrdovidan(thehoeofHirmtodontussimplex~tothebaseofNemopagngraciliszone,Wangatal.,1992)sealeVelchangeSandtheirworldwidecorrelationbasedonasyntheticalstudyofseqUenCe,bioshatiglaphyandaretratigl'aphy.Thisapproachwillfillinthe~instudyoftheOrdovidanofChina,andimprovethesu~ionandCO~ionofbio--,litho--andcbronostheigraphy.Mea…     

赣北修水观音阁砾岩特征及其构造意义

有关赣北地区双桥山群内角度不整合和地壳运动存在与否问题,一直争论不休。论文以较丰富的详细野外调查资料为基础,并结合前人研究成果和室内各类样品测试结果,围绕这个赣北地区重要的基础地质问题进行了讨论。作者认为“修水运动”不能成立,并提出了砾岩的沉积模式。     

岩浆活动与油气成藏地质条件的关系

结合国内外众多含油气盆地中岩浆活动对油气生储盖及圈闭等条件的影响，探讨了岩浆活动与油气成藏地质条件的关系。岩浆活动伴随的高热流可以提高盆地古地温，加速烃源岩演化，亦将使与岩浆岩毗邻的烃源岩达到高成熟或过成熟；岩浆岩及其围岩蚀变带可成为良好的特殊储层；岩浆活动还可形成一些特殊类型的圈闭。另一方面，若岩浆活动时间与油气生成、运移与聚集时间不匹配，将对油气藏的形成与保存起较大的破坏作用。     

鄂西娄山关组顶部古岩溶不整合面的发现及层序地层学意义

鄂西娄山关组顶部存在古岩溶不整合面，有众多陆上暴露和溶蚀标志，表明其产生受寒武纪末海平面下降事件的控制。它不仅形成了碳酸盐台地上典型的Ⅱ型层序界面，而且恰与寒武—奥陶纪年代地层界线相重合，体现了层序界面、年代界线和事件界线三位一体的有机结合     

鄂尔多斯地区南部与东秦岭早古生代的关系和演化——以中层序(mesosequence)观点述之

鄂尔多斯地区南部和东秦岭北部是华北稳定陆块与秦岭海槽之间的过渡带．早古生代可划分为５个中层序（ｍｅｓｏｓｅｑｕｅｎｃｅ）．ＭＳ－１．包括下寒武统及中寒武统徐庄组，为混水台地沉积体系，时间跨度在３５Ｍａ；ＭＳ－２．包括下寒武统张夏组、上寒武统和下奥陶统冶里—亮甲山组，为清水台地沉积体系，时间跨度近３７．９Ｍａ；ＭＳ－３．包括下奥陶统马家沟组和峰峰组，为蒸发型台地沉积体系，时间跨度近３１Ｍａ．三者组成显生宙第一大层序（ｍｅｇａｓｅｑｕｅｎｃｅ），形成一巨大沉积旋回，为地壳动力伸张所成；ＭＳ－４．包括赵老峪组，为弧后盆地形成的斜坡沉积体系和盆地沉积体系，时间跨度１７Ｍａ；ＭＳ－５．系上奥陶统，包括背锅山组、上店组、两岔口组等，为残留海台地型沉积体系．这两个中层序形成显生宙第二大层序的主体，形成一巨大沉积旋回，为地壳动力挤压所成．     

Magnetostratigraphy and palaeoclimate of Red Clay sequences from Chinese Loess Plateau

Two Red Clay profiles near Xi’an and Xifeng were investigated in an attempt to determine magnetostratigraphic and palaeoclimatic records. The results show that aeolian dust accumulation and the related East Asia palaeomonsoon system had begun by 6.5 Ma, and it is deduced that the Tibetan Plateau had reached a significant elevation at that time. The late Tertiary palaeoclimatic history of the Red Clay as reflected by magnetic susceptibility is reconstructed during the period of 6.5–2.5 Ma. Stepwise increase in susceptibility of aeolian dust accumulation appears to have a close correlation to the uplift processes of the Tibetan Plateau. The remarkable increase of aeolian dust accumulation at 3.2 Ma appears to be due to the influence of global ice volume on the East Asia monsoon. Palaeomonsoon variation during the late Tertiary as recorded in the Red Clay sequences from the Chinese Loess Plateau can be regarded as the product of a number of interacting factors, such as uplift of the Tibetan Plateau, solar radiation, global ice volume, etc. Project supported by the National Natural Science Foundation of China and the Foundation of Xi’an Laboratory of Loess and Quaternary Geology, Chinese Academy of Sciences.     

辽河盆地下第三系层序分析

根据岩性、岩相、地震反射、测井响应、古生物、构造旋回、接触关系及同位素年龄测定等，将辽河盆地下第三系划分为４个层序和１２个亚层序。根据地层层序综合分析，辽河盆地早第三纪具有如下沉积演化特征：①构造运动的控制性；②沉积格架的不均衡性；③沉积演化的阶段性；④沉积中心的迁移性。     

从综合地层学观点论华南浅海相泥盆系—石炭系的分界

生物地层学、事件地层学和层地层学综合研究表明，华南浅海相区与Ｓｉｐｈｏｎｏｄｅｌｌａｐｒａｅｓｕｌｃａｔａ带和Ｓ．ｓｕｌｃａｔａ带之间的界线相当的泥盆系－石炭系的界线不仅高于Ｃｙｓｔｏｐｈｒｅｎｔｉｓ带楔界，而且还应高于引起Ｃｙｓｔｏｐｈｒｅｎｔｉｓ绝灭的海退事件层的顶界。     

陕西关中晚更新世黄土—古土壤序列特征及其记录的古环境变迁

陕西关中盆地的泾阳南塬和西安东郊席王晚更新世黄土剖面底部的Ｓ１古生境是由４层古土壤及与其相间的两层古土壤构成。这是目前发现的黄土高原晚更新世黄土，古土壤序列保存较好的剖面。两剖面的地层结构，磁化率曲线和地球化学组分反映出了１２个温湿，冷干气候变化阶段可以归纳为６个气候变化旋回。