桑托斯盆地L构造Aptian期火山喷发旋回特征与Itapema组介壳灰岩沉积     

赵健  赵俊峰  任康绪  王红平  王朝锋  阳孝法  杨柳 《地质学报》2023,97(2):539-552

桑托斯盆地裂陷初期岩浆活动与储层发育关系密切。本文以盆地L区块火成岩-介壳灰岩复合体为研究对象,通过对火成岩岩石学、年代学测试及钻井、测井资料分析等,首次明确了桑托斯盆地裂陷初期岩浆活动特征及其对介壳灰岩沉积过程的控制,并指出介壳灰岩储层的分布特征。L区块内火成岩分属晚白垩世Santonian期—Campanian期和早白垩世Aptian两期岩浆活动产物,并以Aptian期为主,至少经历了7次不连续喷发和3次侵入过程,形成了块状玄武岩、杏仁状玄武岩和玻基斑状玄武岩(含再沉积玻基斑状玄武岩)等喷发相火成岩和以辉绿岩(局部属粗玄岩)、煌斑岩形式产出的侵入相火成岩。Aptian期岩浆多期活动重塑了古地貌,形成了局部构造凸起,促成并控制了下白垩统Itapema组至少6期介壳灰岩沉积,最终形成了～620 m厚火成岩-介壳灰岩复合体。介壳灰岩储层呈透镜体形状,以“散点式”不连续分布在Aptian期盆内古隆、古断阶(坡)等区域,横向连续性差,垂向连通性受限,其发育规模和质量受古地貌及水深条件等影响。  相似文献   

临南油田街2断块沙三上亚段Ⅴ砂岩组沉积微相研究     

郭涛  张卫海  袁巍 《西安地质学院学报》2010,(4):363-367

基于区域地质背景资料,综合运用岩芯观察、岩相和测井相分析等手段,对临南油田街2断块沙三上亚段Ⅴ砂岩组沉积微相的沉积相标志、类型以及展布特征进行了系统研究。结果表明：临南油田街2断块沙三上亚段Ⅴ砂岩组为一套湖泊三角洲沉积体系,亚相类型为三角洲前缘亚相;沙三上亚段Ⅴ砂岩组主要沉积微相可细分为水下分流河道、水下分流河道间湾、河口坝、远砂坝和前缘席状砂等5种微相,并建立了沉积微相识别模式;沉积特征和沉积微相的平面展布呈现在近东西向剖面上砂体连续性较好,可见河口坝与前缘席状砂的交替出现,而在近西南—北东向剖面上,砂体横向上一般由水下分流河道过渡到河口坝或前缘席状砂。总之,临南油田街2断块沙三上亚段Ⅴ砂岩组是研究区三角洲形成的高峰期,水下分流河道、河口坝、前缘席状砂为主要的储集砂体。  相似文献   

保山西邑铅锌矿采选工程RQD与RBI对比研究   总被引：2，自引：0，他引：2  

王建国  刘德安  徐世光  张世涛  李洪伟 《云南地质》2010,29(2):220-223,214

用岩石质量指标和岩体块度指数的理论,对钻孔岩心实测资料进行分析和对比研究,对钻孔周围岩体进行分级。结果表明:岩体块度指数在岩石质量评价中能更准确地反映其优越性,具有更为显著的工程意义。  相似文献   

川滇西部上新世以来构造地貌:断裂控制的盆地发育及对于远程陆内构造过程的约束   总被引：4，自引：0，他引：4  

唐渊  刘俊来 《岩石学报》2010,26(6):1925-1937

青藏高原隆升、周边地貌形成是新生代时期印度-欧亚板块碰撞后的重要响应。在滇西北地区发育了一系列由晚新生代(上新世以来)活动断裂所控制的盆地,例如宾川盆地、洱海盆地、鹤庆盆地、弥渡盆地等。宾川盆地是近南北向程海左行走滑断裂在走滑剪切作用下产生的北西向正断层和北东向走滑断层共同作用而形成的一个较大的拉分盆地。洱海盆地是由两组陡立的共轭张剪性(Transtensional)断层组限定的,为一伸展断陷盆地,总体上反映了近E-W向的区域伸展。滇西北地区发育的其它晚新生代盆地,如弥渡盆地、鹤庆盆地、剑川盆地等,也为区域走滑断裂及其分支断裂所控制,并且这些分支断裂在区域上为一组NE-SW和NW-SE向的共轭正断裂,反映了该区域近E-W向的伸展。将藏东南三江地区发育的活动断裂按照其走向分为三组:(1)NW-SE走向的断裂,如红河断裂、无量山-营盘山断裂等;(2)近N-S向断裂系,以程海断裂、小江断裂等为代表;(3)NE-SW走向的断裂,如丽江-剑川断裂、鹤庆-洱源断裂和南定河断裂等。这些断裂的震源机制解表明地震断裂活动性或者是走滑性质或者是伸展属性,它们的组合型式也揭示出藏东南三江地区在上新世以来表现为近E-W向的伸展。区域上,在藏东北部地区发育的断层构造组合普遍反映了以近E-W向挤压为主导的应力场。推测这一现象为上新世以来藏东地区上地壳围绕喜马拉雅东构造结做顺时针旋转所致,区域上受印度-欧亚会聚过程中印度板块顺时针旋转诱发的差异性应力场制约。  相似文献   

黑龙江萝北地区黑龙江杂岩年代学研究   总被引：21，自引：8，他引：13  

李旭平  孔凡梅  郑庆道  董晓  杨振毅 《岩石学报》2010,26(7):2015-2024

黑龙江杂岩主要出露在牡丹江断裂以东,并沿其呈南北向带状展布于佳木斯地块西缘。对出露于黑龙江省东部萝北地区金满屯太平沟含云母绿帘角闪岩和头道沟的混合花岗岩的锆石进行LA-ICP-MSU-Pb定年研究,获得两组较好206Pb/238U年龄数据:其加权平均年龄分别为256.0±1.0Ma(n=15,MSWD=0.89)和227.1±1.4Ma(n=11,MSWD=1.3)。含云母绿帘角闪岩和混合花岗岩显示了佳木斯地块与其西缘的洋壳俯冲过程中不同阶段或时期的产物。含云母绿帘角闪岩256.0±1Ma的年龄是其变质时代,代表了俯冲、拼贴、碰撞过程中早期的热事件;而混合花岗岩227.1±1.4Ma的年龄则代表了俯冲、拼贴、碰撞过程即将结束的热事件。结合佳木斯地块上出露的同碰撞火山弧花岗岩的形成年代,推断出佳木斯地块与其西缘的松嫩地块之间洋壳的俯冲消减作用和随之而来的陆陆碰撞作用发生在约317～220Ma之间,黑龙江杂岩主体的形成时代为海西晚期到印支期,而其蓝片岩相变质作用可能发生在256Ma之前。  相似文献   

黑龙江老柞山金矿床地质、地球化学特征及其成矿构造背景     

李明飞  叶松青  杨言辰  张国宾  侯晓光  明添学  唐忠 《世界地质(英文版)》2014,(3)

在对老柞山矿床地质特征系统研究的基础上,对与成矿有关的岩石开展了进一步的主、微量元素地球化学测试分析。结果显示与成矿有关的花岗岩具富Sr、低Ti的高钾钙碱性火山弧花岗岩的特征,闪长玢岩具偏铝质钙碱性岩系列特征。岩石样品均呈现出富集轻稀土元素和大离子亲石元素（LILEs）、相对亏损重稀土元素和Nb、 Ta、 Ti等高场强元素（ HFES）的特征,显示了与岛弧或活动大陆边缘岩浆岩相似的属性。流体包裹体特征显示,成矿流体主要来自岩浆水,矿床具中低温（125.6℃～324.5℃）、中浅成（1.0～7.1 km）成矿的特点。与成矿有关岩浆岩显示幔源岩浆特征,可能是地幔交代作用部分熔融所形成的。结合区域上同时期的火成岩时空展布认为,老柞山金矿床成矿可能分别与晚古生代古亚洲洋板块北向俯冲作用和中生代太平洋板块俯冲作用密切相关。  相似文献   

Lopingian mixed floras from Linxi Formation in Soron area,Inner Mongolia     

ZHANG Dejun  ;SUN Yuewu  ;DING naisheng  ;YANG Zhenyuan  ;TANG Lijing 《东北亚地学研究》2014,(2):67-77

A lot of well-preserved plants from the Linxi Formation are collected in the Soron area,Inner Mongolia,consisting of 34 species of 16 genera. They are Late Permian in age. The flora is characterized by a lot of Angaran plants,such as Paracalamites,Comia,Rhachiphyllum,Iniopteris,Rufloria,etc. Some Cathaysian elements,such as Lobatannularia lingulata,L. multifolia,Fascipteris Cathaysiantus,F. densata,Taeniopteris szei,Cladophlebis liulinensis and C. permica,are also mixed within the present flora. This indicates that the Soron of Inner Mongolia was located in the sector between the Angaran and Cathysian floristic provinces in Lopingian. It is beneficial for depicting the location and the evolution of the Solenker--Xar Moron suture zone in the phytogeographic view. The transmigration of tropical and subtropical Cathaysian plants to the north indicates that the Paleoasian Ocean was closed during the late Permian along the suture zone.  相似文献   

Structural evolution of Malay Basin,its link to Sunda Block tectonics     

《Marine and Petroleum Geology》2014

The Malay Basin is located offshore West Malaysia in the South China Sea, within north central region of 1st order Sunda Block. The basin developed partly as a result of tectonic collisions and strike-slip shear of the Southeast Asia continental slabs, as the Indian Plate collided into Eurasia, and subsequent extrusion of lithospheric blocks towards Indochina. The Sunda Block epicontinental earliest rift margins were manifested by the Palaeogene W–E rift valleys, which formed during NW–SE sinistral shear of the region. Later Eocene NW–SE dextral shear of (2nd order) Indochina Block against East Malaya Block rifted open a 3rd order Malay Basin. Developed within it is a series of 4th order N–S en-echelon ridges and grabens. The grabens and some ridges, sequentially, host W–E trending 5th order folds of later compressional episodes. The Malay Basin Ridge and Graben Model explains the multi-phased structural deformation which started with, the a) Pre-Rift Palaeo/Mesozoic crystalline/metamorphic Basement, b) Synrift phase during Paleogene, c) Fast Subsidence from Late Oligocene to Middle Miocene, d) Compressional inversion of first Sunda fold during Late Miocene, and e) Basin Sag during Plio-Pleistocene with mild compressional episodes. The subsequent Mio-Pliocene folding history of Malay Basin is connected to the collision of Sunda Block against subducting Indian–Australian Plate. This Neogene Sunda tectonics, to some degree after the cessation of South China Sea spreading, is due to the diachronous collision along the 1st order plate margins between SE Asia and Australia.  相似文献   

瑞雷波检测技术在强夯块石地基中的应用     

高文信 《云南地质》2014,(2):268-272

基于瑞雷波测试原理及测试方法,主要研究了瑞雷波检测结果在含块石人工填土强夯地基处理中的应用.瑞雷波检测数据不仅可以对场地均匀性及有效加固深度进行评价,采这数据,结合其它检测手段,还可以确定强夯地基的变形模量、地基承载力、地基沉降量等地基参数,具有现实的工程指导意义.  相似文献   

Early Paleozoic tectonic evolution of the Xing-Meng Orogenic Belt: Constraints from detrital zircon geochronology of western Erguna–Xing’an Block,North China     

《Journal of Asian Earth Sciences》2014

To better constrain the Early Paleozoic tectonic evolution of the western part of the Erguna–Xing’an Block, detrital zircon U–Pb dating was applied on the Ordovician to Devonian sedimentary strata along the southeast part of the China–Mongolia border. Most of the zircons from five sedimentary samples display fine-scale oscillatory growth zoning and Th/U ratios higher than 0.1, indicating a magmatic origin. All five Ordovician–Devonian samples display the similar age distribution patterns with age groups at ∼440 Ma, ∼510 Ma, ∼800 Ma, ∼950 Ma, and few Meso- to Paleo-Proterozoic and Neoarchean grains. This age distribution pattern is similar to those from adjacent blocks in the southeastern Central Asian Orogenic Belt. Considering previous tectonic studies, we propose bidirectional provenances from the Erguna–Xing’an Block and Baolidao Arc.Consequently, a new model was proposed to highlight the Early Paleozoic tectonic evolution of the western Erguna–Xing’an Block, which constrains two main Early Paleozoic tectonic events of the Xing-Meng Orogenic Belt: (a) pre-Late Cambrian collision between Erguna–Kerulen Block and Arigin Sum-Xilinhot-Xing’an Block; (b) the Early Paleozoic subduction of Paleo-Asian Ocean and pre-Late Devonian collision between Erguna–Xing’an Block and Songliao-Hunshandake Block.  相似文献