新疆乌恰县乌拉根铅锌矿床地质特征和S-Pb同位素组成

乌拉根矿床是喀什中新生界凹陷内新近勘查的具超大型远景的铅锌矿床。铅锌矿体呈板状,顺层分布于乌拉根向斜南、北两翼,容矿地层为下白垩统克孜勒苏群第五岩性段(K1kz5)褪色灰白色砂砾岩及古新统阿尔塔什组(E1a)泥质白云岩。矿石具块状、微细浸染状、细脉状、团斑状等构造及胶结结构、交代反映边结构等。乌拉根矿床硫化物δ34S值为-27.9‰~14.6‰,指示相邻层位中石膏、天青石等硫酸盐提供硫,同时有机物的热分解也可能作为硫的来源,硫的还原可能包括生物还原与有机质热化学还原两种模式。硫化物的206Pb/204Pb、207Pb/204Pb、208Pb/204Pb分别为18.528~18.663、15.611~15.669、38.616~38.839,极为均一,指示上地壳和造山带剥蚀区是成矿金属的来源。综合分析乌拉根铅锌矿床地质、地球化学特征,并与已有成因认识进行对比,判定乌拉根矿床是与盆地流体活动相关的砂岩型铅锌矿床。     

济阳坳陷中-新生代叠合盆地及油气成藏

济阳坳陷中-新生代盆地是多次构造与沉积叠加形成的叠合盆地.通过分析不同走向断裂的活动特征,明确了中-新生代控盆断层经历了印支构造运动晚期北西(西)向逆冲断层、燕山构造运动中晚期北西(西)向断层构造反转、燕山-喜马拉雅构造运动过渡期北西(西)向断层的消亡及北东(东)向断层的产生3次重要的发育及转型阶段.将济阳坳陷中-新生代叠合盆地划分出"中凹新凹"、"中凹新凸"、"中凸新凹"、"中凸新凸"4种类型的叠合单元,探讨了叠合盆地中断层叠合、界面叠合以及构造叠合对油气成藏的作用,建立了中生界油气成藏模式,指出了"中凸新凹"型叠合单元与"中凹新凸"型叠合单元是中生界最为有利的成藏场所.     

南黄海中部隆起海相中-古生界科学钻探CSDP-2井选址

2014年,大陆架科学钻探项目（CSDP）确定采用自主研发的轻便型海洋钻井平台"探海1号"在南黄海盆地中部隆起上实施首口科学钻探井（CSDP-2井）,其科学目标是探查中部隆起的中-古生界地质结构和油气地质条件,解决南黄海中部隆起海相残留盆地长期悬而未决的地层属性问题,同时为区域地质、海陆演化与海相油气资源前景研究和评价提供基础资料。据此确定钻孔的选址原则为：钻探海域水深不超过30 m,在预定2 800 m的钻探深度范围内钻遇多套完整的中-古生界海相地层。根据钻探目标和选址原则,针对中部隆起没有钻探资料的状况,以区域地质特征和周边钻井对比为参考,以地震资料多属性解释为手段,标定了地震反射层位,解释并编制了反射层构造图,拟定了钻探井位,预测了钻探层位;采用地震储层预测技术预测了有利储层。上述工作形成了无井勘探区的钻探井位部署技术流程和方法,经钻探厘定了三叠纪-奥陶纪海相沉积层,并发现了多个油气显示层,达到了预定钻探目标。     

非洲乍得盆地玄武岩K-Ar和39Ar-40Ar年代学及其动力学背景

乍得的Doba、Bongor和Lake Chad盆地是早白垩世中非右行走滑应力场控制下形成的一系列中新生代陆内拉分盆地,形成与中、赤道及南大西洋打开有关。钻井揭示了盆地内分布有大量的中新生代玄武岩。系统的K-Ar、Ar-Ar法年代学研究发现,至少可识别出2个周期的火山活动旋回,即（1）95-75Ma,只分布于Doba盆地;（2）66-52Ma,分布于Bongor和Lake Chad盆地。研究表明,乍得盆地内中新生代火山活动是板内伸展应力机制下的产物,与白垩纪整个西中非地区的区域构造背景相一致,岩浆作用与裂谷作用密切相关。     

柴达木盆地北缘晚中生代—新生代构造应力场——来自构造节理分析的证据

柴达木盆地的构造演化,尤其是中、新生代的构造演化历史及其影响程度一直存在争议。在冷湖0号、冷湖4号、鄂博梁、结绿素等剖面开展了野外构造节理测量,应用地层恢复技术,分析了柴北缘晚中生代—新生代构造应力场的演化过程。结果表明：晚侏罗世之后,柴北缘主要受东西方向的挤压,这与区域上的研究结果一致;早白垩世北西—南东向的挤压应力可能再次影响了侏罗系;晚白垩世受南北挤压应力的影响,地层隆升遭受剥蚀;始新世下干柴沟期至上新世狮子沟期,柴北缘处于弱活动时期,接受稳定沉积;上新统狮子沟组沉积之后,由于阿尔金山的隆升,盆地北缘主体受北西—南东向应力的影响,涉及地层包括上干柴沟组、下油砂山组和上油砂山组;早、中更新世七个泉期之后,受南北向构造应力场的强烈影响,在狮子沟组、上油砂山组和下油砂山组中都有其分量,较老地层的地表露头中也有记录,这期构造运动对柴北缘油气运聚具有破坏和二次成藏的作用。因此,围绕柴北缘其他地质剖面开展更进一步的构造节理测量和分析工作,对油气资源勘探具有指导意义。     

Reflection on international geo-relations in the Post-Cold War Era北大核心CSSCI

International geo-relations are the basis of national policy making, which play a vital role in the course of a country's development. In this paper, we systematically reviewed the thinking venation of modern geopolitics. According to the characteristics of different periods, it can be divided into three periods: the Empire Stage, the Cold War and the Post-Cold War Era. From the perspective of space, the traditional comprehensive geo-space was deconstructed into multiple dimensions including geographic space, political space, military space, institutional space, information space, technological space, economic space and cultural space. Its connotation and interactive mechanism were interpreted to help understand and analyze the current international geo-relations. Combined with the basic national conditions, China should strengthen the study of international geo-relations, enhance the development of geo-space, follow the Tai Ji international geostrategy and develop effective sphere of influence in the new era. © 2020 The Author(s).     

Mesozoic-Cenozoic Basin Features and Evolution of Southeast China

The Late Triassic to Paleogene(T_3-E) basin occupies an area of 143100 km~2,being the sixth area of the whole of SE China;the total area of synchronous granitoid is about 127300 km~2;it provides a key for understanding the tectonic evolution of South China.From a new 1:1500000 geological map of the Mesozoic-Cenozoic basins of SE China,combined with analysis of geometrical and petrological features,some new insights of basin tectonics are obtained.Advances include petrotectonic assemblages, basin classification of geodynamics,geometric features,relations of basin and range.According to basin-forming geodynamicai mechanisms,the Mesozoic-Cenozoic basin of SE China can be divided into three types,namely:1) para-foreland basin formed from Late Triassic to Early Jurassic(T_3-J_1) under compressional conditions;2) rift basins formed during the Middle Jurassic(J_2) under a strongly extensional setting;and 3) a faulted depression formed during Early Cretaceous to Paleogene (K_1-E) under back-arc extension action.From the rock assemblages of the basin,the faulted depression can be subdivided into a volcanic-sedimentary type formed mainly during the Early Cretaceous(K_1) and a red -bed type formed from Late Cretaceous to Paleogene(K_2-E).Statistical data suggest that the area of all para-foreland basins(T_3-J_1) is 15120 km~2,one of rift basins(J_2) occupies 4640 km~2,and all faulted depressions equal to 124330 km~2 including the K_2-E red-bed basins of 37850 km~2.The Early Mesozoic (T_3-J_1) basin and granite were mostly co-generated under a post-collision compression background, while the basins from Middle Jurassic to Paleogene(J_2-E) were mainly constrained by regional extensional tectonics.Three geological and geographical zones were surveyed,namely:1)the Wuyishan separating zone of paleogeography and climate from Middle Jurassic to Tertiary;2)the Middle Jurassic rift zone;and 3)the Ganjiang separating zone of Late Mesozoic volcanism.Three types of basin-granite relationships have been identified,including compressional(a few),strike-slip(a few), and extensional(common).A three-stage geodynamical evolution of the SE-China basin is mooted:an Early Mesozoic basin-granite framework;a transitional Middle Jurassic tectonic regime; intracontinental extension and red-bed faulted depressions since the Late Cretaceous.     

豫西南中新生代古地理环境变迁

豫西南地区曾经是恐龙生活的“家园”。本文根据区内地层发育和出露特点，结合地壳（构造）活动规律，对豫西南中、新生代自然古地理环境（古地理、古环境、古气候、古生态）进行初步研究。这一研究结果对展示中生代恐龙的自然生态、生活环境，揭示恐龙演化规律和灭绝原因，具有一定的理论和实际意义。     

三国创基立业的地理阐释

地理环境是历史发展的空间,军事活动的“舞台”,是人类生存与发展不可脱离的物质基础。自古以来,人类在地理环境这个舞台上演出了一幕幕惊天动地、可歌可泣的史剧。战争总是在一定地域上进行的,地理环境对于政治、军事力量的抗衡以及作战规模与方式等有着深刻的影响与制约作用。纵观历史,历代区域政治、军事力量间的抗衡多有一定的地理背景与自然基础。而魏、蜀、吴三国鼎立也概莫能外。剖析魏蜀吴创基立国的地理背景,自然基础以及政治、军事活动与地理环境的关系无疑是有意义的     

Mesozoic and Cenozoic collisional structures of the southern Great Altai

We suggest a model of the continental collisional framework of the southern Great Altai (Central Asia) produced by the convergence of the Tuva-Mongolia and Jonggaria terranes (microplates) during the latest Permian-Mesozoic and Cenozoic tectonic activity. The collisional structures in the region classified on the basis of their geometry and deformation style, dynamic metamorphism, and compositions of tectonites are of three main types: (i) mosaic terranes made up of large weakly deformed Paleozoic blocks separated by younger shear zones, (ii) collisional deformation systems involving post-Paleozoic structures, parallel faults oriented along collisional deformation systems, and relict lenses of Paleozoic orogenic complexes, and (iii) isolated zones of dynamic metamorphism composed mostly of collisional tectonites.