层序和体系域的有机相构成及其研究意义

层序地层学为沉积盆地的充填史分析和储层预测提供了有效的格架，但其在源岩评价和预测中的意义未能引起充分的重视。本文对莺海、琼东甫盆地的各沉积层序进行了有机相分析，发现（１）浅水型沉积层序中各体系域的机相构成基本相同，且有机相的侧向变化不明显；（２）在深水型层序中，海进体系域上部和高位体系域下部有机质丰度较高、类型较好，有机相层序呈Ｓ性，但有机的侧向变化明显；（３）多层序有机相的总体演化趋势反映了盆地     

鄂尔多斯盆地中南部上古生界层序与岩相古地理演化*

为明确鄂尔多斯盆地中南部上古生界层序特点与岩相古地理演化规律,利用周缘野外露头和盆地钻井测井相特征,分析层序界面、体系域界面的岩性、古构造及海侵方向变化特征,总结层序发育特点与岩相古地理演化规律。结果表明: 不同风化序列的区域性不整合面及海侵方向转换面为二级层序界面,区域性海退面、下切冲刷面及陆上暴露面为三级层序界面; 潮间带砂坪及近岸相海侵含砾砂岩顶为海侵面,最大海侵面发育灰岩、泥页岩及煤层,是海侵体系域与高位体系域分界面; 上古生界包括二级层序2个: MSQ1、MSQ2,三级层序6个: SQ1、SQ2、SQ3、SQ4、SQ5、SQ6,其中SQ1—SQ2发育水进体系域与高位体系域,不发育低位体系域,SQ1为潟湖—障壁海岸沉积体系,SQ2为泥炭坪—泥坪相潮坪沉积;SQ3—SQ6发育完整的低位—海侵—高位体系域,SQ3发育区域性海退进积海陆过渡相三角洲沉积,SQ4早期为低位体系域下切冲蚀砂体,晚期沉积古环境由温暖湿润还原环境演变为炎热干燥的氧化环境,SQ5—SQ6早中期为氧化环境三角洲沉积,SQ6晚期为高位体系域具海侵夹层的潮坪相沉积。研究为鄂尔多斯盆地及其他盆地层序与岩相古地理演化提供理论依据。     

Holocene transgression of the Rhine river mouth area,The Netherlands/Southern North Sea: palaeogeography and sequence stratigraphy

This study presents a detailed reconstruction of the palaeogeography of the Rhine valley (western Netherlands) during the Holocene transgression with systems tracts placed in a precise sea‐level context. This approach permits comparison of actual versus conceptual boundaries of the lowstand, transgressive and highstand systems tracts. The inland position of the highstand Rhine river mouth on a wide, low‐gradient continental shelf meant that base‐level changes were the dominant control on sedimentation for a relatively short period of the last glacial cycle. Systems in such inland positions predominantly record changes in the balance between river discharge and sediment load, and preserve excellent records of climatic changes or other catchment‐induced forcing. It is shown here that the transgressive systems tract‐part of the coastal prism formed in three stages: (i) the millennium before 8·45 ka bp , when the area was dominated by fluvial environments with extensive wetlands; (ii) the millennium after 8·45 ka, characterized by strong erosion, increasing tidal amplitudes and bay‐head delta development; and (iii) the period between 7·5 and 6·3 ka bp when the Rhine avulsed multiple times and the maximum flooding surface formed. The diachroneity of the transgressive surface is strongly suppressed because of a pulse of accelerated sea‐level rise at 8·45 ka bp . That event not only had a strong effect on preservation, but has circum‐oceanic stratigraphical relevance as it divides the early and middle Holocene parts of coastal successions worldwide. The palaeogeographical reconstruction offers a unique full spatial–temporal view on the coastal and fluvial dynamics of a major river mouth under brief rapid forced transgression. This reconstruction is of relevance for Holocene and ancient transgressive systems worldwide, and for next‐century natural coasts that are predicted to experience a 1 m sea‐level rise.     

塔里木盆地台盆区三叠系三级层序界面和体系域界面的识别与应用

尽管前人对塔里木盆地塔北地区三叠系进行过沉积与层序地层研究,但是有关全盆范围内层序地层格架研究比较少见。应用现代沉积学和层序地层学的原理和方法,着眼于塔里木盆地台盆区的整体研究,综合利用地震、钻井、测井及分析化验等资料,对研究区三叠系三级层序界面和体系域界面进行识别,共识别出5个具有等时意义的层序界面,对应划分为4个三...     

论海平面变化与层控矿床成因

桂北及桂中大瑶山西侧泥盆纪层控型站矿床成因研究表明，矿床形成赋矿盆地的海平面变化密切相关，它们是“层、系、相、位”四位一体主因素地质场作用的结果，这一新的矿床成因新模式可以概括为：区域赋矿层位与层序边界面关系密切，研究区内共划分出７个 序边界面，其中ＳＢ１（Ｉ），ＳＢ３（Ⅲ）及ＳＢ７（Ｉ）是主要的区域性赋 层位；矿体一般产于Ｉ型层序边界面之上，或产于Ⅱ，Ⅲ层序边界面之下；容矿主岩与一定的沉积体系域     

米仓山西段晚元古代-古生代层序地层及地层模型

米仓山西段位于扬子地台北缘，该区除缺乏泥盆系和石炭系外，各时代地层均有发育。从震旦系灯影组至二叠系大隆（或长兴）组可划分出１３个相当于Ⅱ～Ⅲ级沉积旋回的层序或复合层序，并建立了地层模型。地台边缘的层序地层和沉积体系域具有它自身的某些特点。由局部构造活动引起的相对海平面变化，对沉积体系域和界面类型有着明显的影响。但是，在这种情况下形成的沉积序列和其它特征，与相应的典型体系域相比有一定的差异。为此，我们引用或引入了上超体系域（ＯＳＴ）、滨浅海边缘楔（ＳＭＷ）、最大海泛沉积层（ＭＦＳ）和Ⅲ类层序界面等概念。     

陆相坳陷型和断陷型湖盆层序地层样式探讨

依据层序地层学基本理论,考虑中国中新生代陆相坳陷型和断陷型湖盆的盆地结构和沉积物充填序列特征,综合利用地质和地球物理资料,以松辽盆地白垩系和准噶尔盆地侏罗系、柴达木盆地第四系和渤海湾盆地第三系为研究实例,将坳陷型湖盆沉积层序细分成可以确定首次湖泛面和不能确定首次湖泛面的两种类型,建立了这两种类型湖盆的层序地层样式。前者由低位、湖侵和高位体系域组成,后者由湖侵和湖退体系域构成。在断陷型湖盆中,可将盆地缓坡由同生断裂活动造成的地势变化带作为地形坡折带(构造坡折带)并用于确定首次湖泛面,进而讨论了首次湖泛面和最大湖泛面的多种识别标志,建立了由低位、湖侵和高位体系域构成的断陷型湖盆层序地层样式。     

Violence Change and Cohort Trajectories: Baltimore Neighborhoods, 1990-20001

Whereas the relationship between poverty and violence is incontrovertible in the American city, demographic relationships at the neighborhood level are relatively poorly understood. Patterns of violence and population change are examined at the census tract level in Baltimore, Maryland across the decade from 1990 to 2000. Aggravated assault and homicide are combined and used as a composite indicator of serious violence. Population data are examined for selected tracts representative of anomalous outliers experiencing population decline but increased violence. The data are broken down into five-year cohorts represented graphically at their beginning (1990) and end (2000) points. The analysis indicates that some neighborhoods have experienced collapse of youthful cohorts. Normally, a decline in youthful population would predict a reduction in crime, but this analysis suggests that at the neighborhood scale criminogenic processes may affect neighborhoods somewhat independently of their demographic attributes. Most notably, population decline at the neighborhood level may be accompanied by crime increase, contrary to macrolevel theoretical expectation.     

辽河滩海西部海南—仙鹤地区古地貌特征及其控砂作用

基于三维地震和测井资料分析,以层序地层分析和古地貌恢复技术相结合,根据地层剥蚀状况,将层序界面分为洼陷带内的平行不整合面、凹陷边缘超覆带的角度不整合面、旋转断块顶部的角度不整合面和潜山顶部强烈剥蚀不整合面4种类型,针对不同的界面类型采用不同的剥蚀地层恢复方法,重建了辽河滩海海南—仙鹤地区关键构造期古地貌形态。研究发现海南—仙鹤地区发育下切谷、陡坡断裂坡折带、古凸起等多种古地貌单元,古地貌整体呈现沟、梁斜列,下切沟谷和陡坡断裂坡折带发育,物源面积大、物源方向与海南断层斜交等特点。古地貌对物源体系、层序构成和砂体分布具有明显控制作用,具有"大沟对大扇,小沟对小扇"、砂体平面上分布受断层坡折控制、纵向分布受体系域控制等特点。     

塔里木盆地下志留统塔塔埃尔塔格组痕迹化石与海进期沉积及海进体系域

在层序地层学研究中,海进（transgrssion）常被认为是快速形成的,序列简单,并以少量沉积为特征。对塔里木盆地下志留统塔塔埃尔塔格组痕迹化石及沉积特征研究表明,海进期沉积及海进体系域比人们想象的要复杂,由三类沉积组成:（1）与海进侵蚀有关,包括海进滞留沉积,发育固底控制Glossifungites痕迹相;（2）与海进初期的海面缓慢上升或总体海进过程中的静止期有关,包括前滨和临滨砂泥岩,发育Skolithos痕迹相和近端Gruziana痕迹相;（3）与海面快速上升有关,包括滨外泥岩,发育远端Gruziana痕迹相。