特提斯域演化对四川超级盆地油气系统形成的影响

基于“单向裂解—聚合”地球动力学模型,研究特提斯域演化对四川超级盆地油气系统形成的影响,探讨天然气富集规律。结果表明:①四川盆地及周缘新元古代—三叠纪历经了原特提斯洋和古特提斯洋叠加影响的两次单向裂解—聚合旋回,侏罗纪—新生代并入新特提斯构造域及环青藏高原盆山体系,板块内部各幕次构造运动控制沉积充填形式。②特提斯域演化、古气候环境和重大地质事件控制了盆地内部优质烃源岩形成与分布;裂谷、克拉通内裂陷、被动大陆边缘斜坡和克拉通内凹陷是烃源岩发育的有利地质构造单元。③特提斯域演化、超级大陆旋回、全球海平面变化以及构造-气候事件控制了碳酸盐台地及储盖组合的分布;克拉通台地边缘、台地内部水下地貌高带是寻找碳酸盐岩高能相带的重点区,同沉积古隆起及围斜区、区域性不整合面和后期改造断裂带是规模碳酸盐岩储层分布区;区域性蒸发岩或者泥页岩盖层有利于盆地油气大规模保存。④早期构造-沉积演化格局和后期构造改造程度共同影响的成藏要素时空匹配关系是油气富集的关键,未来油气勘探要重点关注南华纪裂谷期潜在含气系统,四川盆地东部—南部地区寒武系盐下含气系统以及二叠系、三叠系全油气系统等领域。

内蒙古敖汉地区中生代花岗质岩浆活动与金钼多金属成矿作用

内蒙古敖汉地区处于华北克拉通与兴蒙造山带的过渡区,是华北地台北缘一个重要的金钼多金属矿化集中区,近年来找矿成果丰硕。在对撰山子和金厂沟梁大型金矿、白土营子大型钨钼多金属矿以及近年新发现的八家大型锌银铅矿和腾克力钼矿的地质地球化学特征系统分析的基础上,文章探讨了矿床成因与区域构造岩浆演化,提出了本区金钼多金属成矿潜力与找矿方向。结果显示,敖汉地区金钼多金属成矿与印支期、燕山期花岗质岩浆侵位密切相关,成矿主要发生于三叠纪和晚侏罗世—早白垩世,具有多期多阶段性特征。印支期和燕山期成矿岩体总体均属于准铝质-弱过铝质高钾钙碱性系列花岗岩,表现为轻稀土富集的右倾配分特征,大离子亲石元素富集,高场强元素亏损,分别形成于古亚洲洋和古太平洋构造域影响下的伸展背景。金矿床成因类型主要为岩浆热液脉型,钼矿床成因类型主要为斑岩型,受构造-岩浆岩联合控制,印支期和燕山期中酸性岩浆岩及北西向-近南北向断裂是重要的找矿标志。撰山子金矿具有良好的斑岩-矽卡岩型金铜矿床找矿前景,金厂沟梁和撰山子金矿区及外围具有寻找浅成低温热液型金多金属矿床的潜力。借鉴白土营子钨钼多金属矿田和八家锌银铅矿床的找矿经验,应注重综合利用地质、地化、物探等手段在覆盖区寻找钨铅锌银多金属矿床。

黔西南卡林型金矿隐伏矿找矿中弱信息提取方法研究

黔西南地区是中国卡林型金矿的集中分布区,金矿成矿地质条件优越,找矿潜力巨大。但区内浅表金矿资源已基本找寻殆尽,找矿工作全面进入“攻深找盲”阶段。隐伏金矿由于矿体埋深较大,地表的矿化信息必然非常微弱甚至没有信息显示,深部成矿信息获取困难。如何识别并获取与深部成矿作用有关的地球化学信息,成为制约找矿突破的关键因素。黔西南卡林型金矿的形成及就位主要受背斜及断裂构造的控制,元素地球化学的分布、分异和成矿同样受到构造应力的影响,深部成矿信息通过断裂、裂隙与浅部及地表相联系,浅部构造岩石中的地球化学异常能在一定程度上反映深部的矿致异常。因此,以构造地球化学理论为基础,分析黔西南地区成矿地质条件和相应元素组合的迁移和富集规律,对卡林型金矿隐伏矿找矿地球化学弱信息提取的关键环节进行深入剖析,总结构造地球化学弱信息提取方法指标参数,有效提取深部成矿元素沿构造裂隙向上渗滤扩散形成的弱异常,对深部隐伏矿进行初步定位预测。弱信息识别及提取的相关研究成果对丰富黔西南地区卡林型金矿的成矿理论具有一定的学术价值,同时使用该方法在黔西南金矿隐伏矿找矿上能有效圈定并优选找矿靶区,对落实新一轮找矿突破战略行动任务具有积极的现实意义。

准噶尔盆地西部坳陷带二叠系构造-地层层序与盆地演化

玛湖凹陷、沙湾凹陷和盆1井西凹陷是准噶尔盆地西部三大富烃凹陷,通过对深钻井、测井和深反射地震剖面资料的分析,揭示出这三大凹陷在早二叠世隶属于同一个坳陷,据此厘定了准噶尔盆地西部坳陷带的范围。在西部坳陷带内的二叠系—上三叠统共识别出3套区域性不整合面,依据不整合面划分了3套构造层,分别是下二叠统构造层、中二叠统构造层和上二叠统—三叠系构造层。在此基础上,运用断层相关褶皱理论和平衡剖面技术进行精细构造解析和构造演化分析,并结合前人对于准噶尔盆地热史和火山岩地球化学特征的分析,重点解析西部坳陷带二叠纪—三叠纪的构造演化过程,认为二叠纪—三叠纪西部坳陷带共经历了3期构造演化,分别是早二叠世伸展裂陷阶段(早二叠世末期挤压)、中二叠世弱伸展拗陷阶段和晚二叠世—三叠纪挤压隆升阶段,且西部坳陷带的构造演化与西准噶尔和准噶尔地块的逆时针旋转在时空上相耦合。该研究成果对于揭示准噶尔盆地二叠纪盆地性质及二叠纪以来的陆内演化过程具有重要的意义。

胶东大尹格庄金矿田构造物理化学参量急变带成矿特征

在金属内生矿矿田地质研究中,构造变形岩相既能反映矿田形成的构造应力场特征,又能揭示其地球化学特征和物理化学条件。胶东金矿集中区在全球金矿中独具特色,其金矿储量规模位居世界第三,大尹格庄金矿田是区内特大型金矿田之一。在矿田构造蚀变岩相研究基础上,厘清矿田成矿构造物理化学参量之间的关系,探讨构造作用通过影响矿田成矿物理化学条件驱动金成矿作用问题显得尤为必要。本文选取代表成矿流体成分、温压、性质和成矿构造等条件的构造物理化学参量,采用因子分析法,探讨矿田构造成岩成矿问题。结果显示:流体包裹体成分CO_(2)/H_(2) O、酸碱度(pH)、氧逸度(lgfO_(2))、构造附加静水压力(Ps)、流体包裹体均一温度以及流体包裹体最小压力(Pmin)等参量代表的构造物理化学条件对成矿的影响较大,CO_(2)/H_(2)O、lgfO_(2)、Ps、均一温度、Pmin所代表的成矿流体成分、性质、温压条件及构造作用的影响是正相关的,而pH影响是负相关的;矿田黄铁绢英岩带、黄铁绢英岩化花岗质碎裂岩带和强钾长石化花岗岩带中,构造附加静水压力(Ps)、流体包裹体成分CO_(2)/H_(2) O、氧逸度(lgfO_(2))、流体包裹体最小压力(Pmin)和均一温度均依次呈现先升高再降低的趋势。流体包裹体成分Na^(+)/K^(+)、F^(-)/Cl^(-)参量代表的成矿物理化学条件对于成矿的影响是负相关的,在黄铁绢英岩带、黄铁绢英岩化花岗质碎裂岩带和强钾长石化花岗岩带中,F^(-)/Cl^(-)依次呈现逐渐降低的趋势,Na^(+)/K^(+)则依次呈现逐渐增大的趋势。构造附加静水压力(Ps)能够促使成矿流体从Ps较高的部位向较低的部位运移并沉淀成矿。构造物理化学参量的高低值之间存在构造物理化学界面,金矿体主要位于界面的构造应力松弛部位。

平原M5.5地震土壤气地球化学特征及成因

2023年8月6日2时33分,山东省德州市平原县发生M5.5地震。文中跨震中布设4条长30km的勘测线,现场测量了土壤气Rn、CO_(2)和Hg浓度。结果表明:1)土壤气浓度表现出明显的空间差异,震中区与4条测线的东、西两端气体浓度相对较高。2)土壤气浓度的空间分布特征在震中及其东部地区相似,但在震中西部差异较大,在西部旧城断裂(F_(3))附近,Rn和CO_(2)的浓度高于震中区,推测应与地震活动和F_(3)控制的鼻状构造有关。3)Rn、CO_(2)和Hg的浓度在陵县-冠县断裂(F_(1))和F_(3)附近出现高值异常,余震自F_(1)向F_(3)发展,结合地质与地球物理研究资料推断,平原M5.5地震应与F_(1)和F_(3)共同作用有关。以上结果表明,气体地球化学方法能较好地指示隐伏断层的位置与展布方向。

鄂尔多斯盆地奥陶系马家沟组一段—三段构造沉积演化及其油气地质意义

基于测井、岩心、薄片、地球化学分析,重建鄂尔多斯盆地奥陶系马家沟组一段—三段(简称马一段—马三段)构造-岩相古地理格局,探讨构造沉积演变特征及其油气地质意义。研究表明:①马家沟组底部稳定发育一套穿时的、高自然伽马值段、边缘相泥质白云岩,分布于怀远运动期构造不整合面之上,具有与早奥陶世弗洛期全球海侵可对比的δ13C正漂移特征;②奥陶系马一段—马二段沉积期全球海平面上升、古陆淹没为水下隆起,形成一隆两坳构造格局,中央隆起首次接受沉积;随后马三段沉积期盆外俯冲挤压、盆内隆坳分异,乌审旗—靖边凸起活化;③构造格局演变对沉积古环境产生显著影响,马一段沉积期向西超覆,东部坳陷内海侵封隔形成大规模盐质蒸发潟湖;马二段沉积期持续海侵并沟通广海,环东部坳陷发育大规模颗粒滩,晚期干化收缩形成小规模蒸发潟湖;马三段沉积期受高地封隔影响,向东侧水体渐次分异分别形成云膏质和盐质蒸发潟湖,同时颗粒滩环凹沿高地展布;④马家沟组底部发育烃源岩,马二段和马三段滩相储层环坡展布,源储配置良好,有利于天然气成藏,具有一定勘探潜力。

洋中脊弯折带的构造-岩浆耦合作用:西北印度洋中脊火山锥及断层分布的约束

洋中脊作为全球火山活动最活跃的区域之一,岩浆以裂隙式喷发为主,同时也存在中心式喷发火山锥。本文基于西北印度洋中脊大洋24航次的船载多波束地形数据,选择具有特殊空间位置和构造属性的北部弯折带作为研究靶区,应用定量地貌学方法分析火山锥形态特征与空间分布,探索区域火山作用与构造活动的耦合关系。结果表明,火山锥沿洋脊纵向上的分布主要受控于岩浆供应量,但段内其横向上的分布不仅与岩浆供应量有关,还决定于火山锥岩浆通道的形成。火山锥的分布与断层分布密切相关,断层分布密集,易于火山锥通道的形成。弯折带的洋脊段除了受扩张力外,还受到北东方向的应力作用,使弯折带南翼发育有更密集的断层,更高的火山锥密度。该应力效应的产生与非洲板块的北东向推移、印度板块的逆时针旋转以及弯折带效应本身有关。火山锥形态特征与空间分布,对于理解洋中脊区域构造演化以及火山活动过程具有重要价值。

鄂尔多斯盆地古峰庄地区疑似侵入岩体的发现及其地质意义

鄂尔多斯盆地内部岩浆岩体的发现对于构造-热事件重建、古地温场恢复及油气地质作用解析有重要意义。基于高精度三维地震资料的处理与解释,首次在盆地内部古峰庄地区发现疑似浅层侵入岩体,刻画了其空间展布并探讨了油气地质意义。研究显示,古峰庄地区存在6个疑似侵入岩体,在平面上多呈环状或云朵状,剖面上愈临近岩体核部,地层杂乱反射和丘状构造特征愈明显。据岩体分布形式和地震反射特征,可将其分为“岩浆深分散浅集中上涌型”疑似侵入岩体和“岩浆浅集中上涌型”疑似侵入岩体。前者由深及浅均有杂乱反射现象,与围岩反射特征明显有别,产状近直立,伴生断裂发育。后者仅在1 000 ms等时切片以上的浅部层系呈杂乱丘状反射,其下地层呈正常的层状反射、几乎不见地层扰动现象。分析认为先存断裂的存在及其数量、规模、垂向叠置程度、核部与端部断距以及地层压力,是造成岩浆差异式上涌的主因。结合盆内其他岩浆岩体发育特征和形成时代,认为古峰庄疑似侵入岩体形成于早白垩世晚期,与古生界-中生界油气规模成烃期和成藏期一致,此阶段的热液活动对该区油气生成、保存和成藏具有重大意义。

鄂尔多斯盆地深层中元古界地震波组及构造—地层层序特征

本文利用最新的测井及地震资料,制作并分析对比了20口井的合成记录,对鄂尔多斯盆地中元古界的地震波组特征展开研究,识别出7个反射界面。其中,T0、T1和T3界面反射波振幅强、连续性好,有着稳定的波形特征,为中元古界主要的区域性不整合面,可作为标志层进行对比。在此基础上,总结了本区中元古界7套地震地层的波组特征,并结合野外露头资料,将研究区中元古界划分为7套构造层,即底部古元古界或太古界片麻岩之上的陆源碎屑沉积岩层Pt2-1(大古石组)、中基性火山岩层Pt2-2(许山组)、酸性火山岩层Pt2-3(鸡蛋坪组)、安山岩夹火山碎屑岩层Pt2-4(马家河组)、碎屑岩层Pt2-5(汝阳群)、泥岩—粉砂岩层Pt2-6(洛峪群)、碳酸盐岩层Pt2-7(蓟县系)。研究发现,鄂尔多斯盆地古元古代末期到新元古代发生了多期裂谷活动,影响了中元古代地层及不整合面的发育。熊耳群为华北克拉通裂谷发育初期,在结晶基底之上沉积的第一套盖层,底部大古石组接受陆源碎屑沉积,此后至熊耳群晚期之间发生的火山活动形成安山岩。裂谷作用晚期,汝阳群粗碎屑岩角度不整合于其上,而后海侵最大,洛峪群泥岩平行不整合于其上。至中元古代末期,海水循环良好,蓟县系碳酸盐岩形成,平行不整合于下伏长城系地层之上。

泛扬子克拉通西部地区灯影期构造—沉积格局

勘探实践表明,四川盆地新元古界上震旦统灯影组具有丰富的油气资源,为了科学认识古构造对沉积、储层及油气成藏的控制作用,进一步夯实灯影组下一步勘探理论依据,需要针对灯影期构造—沉积格局进行研究。基于重磁、构造、沉积等资料分析,开展克拉通西部边界的探讨,研究古裂陷的分布与成因;基于构造控制沉积建造的思路,探究晚震旦世灯影期上扬子克拉通沉积格局。研究结果表明:(1)扬子克拉通西界由龙门山—安宁河断裂带向西推延至金沙江—红河断裂带,称为泛扬子克拉通;(2)泛扬子克拉通内发育3支克拉通内裂陷,将泛扬子克拉通西部地区分割成东部和西部两个次级克拉通盆地;(3)东部次级克拉通盆地以白云岩类为主,沉积环境相对局限,西部次级克拉通盆地石灰岩类厚度较大,沉积环境相对开放;(4)克拉通内裂陷及其两侧台缘带的沉积建造构建了优越的侧向对接源—储成藏组合,是目前灯影组重点勘探对象,万源—达州裂陷带是值得关注的勘探区。

Tectono-Sedimentary History of Southeastern Coast Region,China:a Synthesis

According to the ideas and concepts of systems dynamic of continent structure, using previous information related to the study area, combining analyses on orogenic belt, basin and magmatic rock, the present paper synthesizes the tectono - sedimentary development of southeastern coast region, China, with special emphasis on the mountain making, basining and magmatic activity. The tectonic evolution after Late Caledonian orogeny was dominated by alternating rifting and converging, subsiding and uplifting, mountain making and basining in central and southern parts of southeastern China and the adjacent regions to the east and west. Seventeen geologic events , nine events of plate or terrain convergence , and continental crust accretion , as well as eight events of intracontinental rifting and basin faulting , are closely related to the tectonic and sedimentary evolution of the study area . The accompanied intense and frequent sedimentation , folding , faulting , magmatism and ore- forming process allowed huge coal , multimetal and potential petroleum source rocks to form in local depressions throughout the Caledonian to Himalavan time .

Tectono–sedimentary Evolution of the Late Triassic Xujiahe Formation in the Sichuan Basin

The early stage of Sichuan Basin formation was controlled by the convergence of three major Chinese continental blocks during the Indosinian orogeny that include South China,North China,and Qiangtang blocks.Although the Late Triassic Xujiahe Formation is assumed to represent the commencement of continental deposition in the Sichuan Basin,little research is available on the details of this particular stratum.Sequence stratigraphic analysis reveals that the Xujiahe Formation comprises four third-order depositional sequences.Moreover,two tectono-sedimentary evolution stages,deposition and denudation,have been identified.Typical wedge-shaped geometry revealed in a cross section of the southern Sichuan Basin normal to the Longmen Shan fold-thrust belt is displayed for the entire Xujiahe Formation.The depositional extent did not cover the Luzhou paleohigh during the LST1 to LST2 （LST,TST and HST mean Iowstand,transgressive and highstand systems tracts,1,2,3 and 4 represent depositional sequence 1,2,3 and 4）,deltaic and fluvial systems fed sediments from the Longmen Shan belt,Luzhou paleohigh,Hannan dome,and Daba Shan paleohigh into a foreland basin with a centrally located lake.The forebulge of the western Sichuan foreland basin was located southeast of the Luzhou paleohigh after LST2.According to the principle of nonmarine sequence stratigraphy and the lithology of the Xujiahe Formation,four thrusting events in the Longmen Shan fold-thrust belt were distinguished,corresponding to the basal boundaries of sequences 1,2,3,and 4.The northern Sichuan Basin was tilted after the deposition of sequence 3,inducing intensive erosion of sequences 3 and 4,and formation of wedge-shaped deposition geometry in sequence 4 from south to north.The tilting probably resulted from small-scale subduction and exhumation of the western South China block during the South and North China block collision.

Cenozoic evolution of tectono-fluid and metallogenic process in Lanping Basin, western Yunnan Province, Southwest China: Constraints from apatite fission track data

Since the Mesozoic, abundant metal and salt deposits have been formed in the Lanping Basin, western Yunnan Province, Southwest China, constituting a well-known hydrothermal ore belt in China. Most of the deposits are meso-epithermal hydrothermal deposits. This paper preliminarily deals with the mineralization ages of hydrothermal deposits in the Lanping Basin by using the apatite fission track method, and integrates the spatial distribution of the deposits and their regional geological backgrounds, to give the preliminary viewpoints as follows: (1) the apatite fission track ages acquired range from 19.9 Ma to 52.8 Ma, much younger than those of their host strata, so they may be considered to be mineralization ages, which represent the late mineralization period; (2) the apatite fission track ages tend to become younger from the west to the middle of the basin, indicating that the latest evolution of tectono-fluid and/or metallogenic processes of the middle basin ended later than that in the west; (3) in the Paleogene, most of the Cu deposits were formed in the western part of the basin; (4) the major metallogenic processes occur between the Paleogene and the Neogene, because the eastern and western edges of the basin were subducted into and collided with its bilateral continental blocks, respectively, and the central fault was strongly activated, which led to the processes of large-scale ore-forming fluids, and their differentiation and transport because of the variation of their physical and chemical properties. Having been squeezed and uplifted, the Lanping Basin became an intermontane basin that contains many kinds of fluid traps resulting in the formation of different types of ore deposits (for example, Pb-Zn, Cu, Ag) of different scales in the middle of the basin. Simultaneously, the fluids with volatile elements such as Hg, Sb and As were transported upwards along the central fault system and diffused into its subordinate fractures, thus leading to the metallogenic processes of Hg, Sb and As in the eastern composite anticline of the Lanping Basin; (5) and later, these ore deposits experienced reformation and oxidization. To summarize,deep giant faults were active in the basin, and metallogenic processes were constrained by the evolution of tectono-fluids in the Lanping Basin. Simultaneously, the occurrence of the metallogenic processes made the nature of fluid and the structural environment change, which led to returning and recycling of the fluids. Multi-stage and zonational metallogenic processes are the characteristics of the ore deposits in the Lanping Basin.

Cenozoic tectono-sedimentary characteristics and extension model of the Northwest Sub-basin,South China Sea

Based on the interpretations of three seismic profiles and one wide-angle seismic profile across the Northwest Sub-basin,South China Sea.stratigraphic sequences,deformation characteristics and an extension model for this sub-basin have been worked out.Three tectonic-stratigraphic units are determined.Detailed analyses of extension show that the event occurred mainly during the Paleogene and resulted in the formation of half-grabens or grabens distributed symmetrically around the spreading center.Sediments are characterized by chaotic and discontinuous reflectors,indicating clastic sediments. Farther to the southwest,the sub-basin features mainly continental rifting instead of sea-floor spreading. The rifting would have been controlled by the shape of the massif and developed just along the northern edge of the Zhongsha-Xisha Block,rather than joined the Xisha Trough.After 25 Ma.a southward ridge jump triggered the opening of the Southwest Sub-basin.The NW-directed stress caused by the sea-floor spreading of the Northwest Sub-basin may have prevented the continuous opening of the sub-basin.After that the Northwest Sub-basin experienced thermal cooling and exhibited broad subsidence.The deep crustal structure shown by the velocity model from a wide-angle seismic profile is also symmetrical around the spreading center,which indicates that the Northwest Sub-basin might have opened in a pure shear model.

Geological characteristics of the Sizhuang gold deposit in the region of Jiaodong, Shandong Province——A study on tectono-geochemical ore prospecting of ore deposits

Tectono-geochemical samples were systematically collected from 5 drillcores along the No. 304 explora-tion line and at the -310 m level under the pit in the mining area, totalling 705 samples from the metamorphic rocks, granites, altered rocks and orebodies, and were determined for their contents of 20 kinds of elements including Au, Ag, As, Sb, Hg, Cu,,Pb, Zn, Sn, Bi, Mo, Co, Ni, Mn, Cr, V, Ti, Ba, Rb, Sr, etc. By using the Surfer software the geochemical exploration line profile maps for the 20 kinds of elements and the curves for the element geochemical contents of individual ore vein groups were established. In conbination with the geochemical map analytical method and Gregorian's zoning index calculation method, the vertical, longitudinal and lateral zonation sequences of the elements were ascertained and the geochemical three-dimentional zonation model of the primary halos was estab-lished on the basis of the analysis of metallogenic structures and alteration zonation. Coupled with the results of analysis of the geology and geochemistry data, it may be concluded that the process of alteration of granites in the mining area is also accompanied with the process of gold enrichment and mineralization. With the intensification of alteration of granites from granite →potash feldspathization granite →sericite-quartz alteration granite, seric-ite-quartz rocks →beresitized granite, pyrite sericite-quartz rock, silicified granite →gold ore, the contents of thio-phile ore-forming elements such as Au, Ag, As, Cu, Bi, Mo, Pb, Sb, Hg, and Sn tended to increase. Factor analysis of trace elements indicated: factor F2 (Au, Ag, Cu, Sn, As) represents the element association brought in at the main stage of hydrothermal metallogenesis; factor F4 (Bi, Sb) and factor F5 (Pb, Zn) represent the ore-forming element association supperposed during the late stage of Au-bearing sulfides. By using the Gregorian's zoning index and map analysis method we have ascertained the primary halo axial zonation sequence (form frontal halo →tail halo): Pb, Zn, Mn, Ba, Sr, Rb, As, Sb, Ag, Cu, Sn, Mo, Au, Bi, Hg, Ti, Cr, V, Ni, and Co. The geochemical anomalies in the mining area display a tendency of lateral plunging to WS, which is consistent with the lateral plunging of orebodies and mineralization alteration zone. Comprehensive analysis of the results of investigations on ore-controlling structures, mineralization-alteration zonation and geochemical zonation of the primary halos indicates that the gold orebodies in this area are still of greater extension.

Ore-finding method of fault tectono-geochemistry in the Tongchang Cu-Au polymetallic orefield, Shaanxi, China:Ⅰ. Dynamics of tectonic ore-forming processes and prognosis of concealed ores

Based on the research content and conception of dynamics of tectonic ore-forming processes, with the focus on the dynamics and processes of mineral source, ore formation, transport, accumulation, dissipation and mineralization in response to magmatic invasion and metallogenic fluid under tectonic stress, this paper deals with the ore-finding method of fault tectono-geochemistry and its application on the basis of ore deposit genesis, "giant pressure shadow" structure and ore-finding method of tectonic stress field in the Tongchang orefield, expounds the rules of magmatic emplacement and ore fluid migration and concentration under the control of the structural stress field, hence providing the theoretical basis for the localization and prognosis of concealed ores. The fault tectono-geochemical features show that the Cu-Au polymetallic ore deposits (mineralization) in the orefield are closely related with volcano-(exhalation) sedimentation, magmatism and tectono-reworking. Fault tectono-geochemical anomalies can be applied to prognosis of metallogenetic target areas for ore exploration and can provide strong evidence of "giant pressure shadow" structure. In addition, quite a number of important target areas have been defined in combination with the characteristics of the tectonic stress field, and part of the target areas have been proved by practical activities.

Application of Tectono Geochemical Study in Deep Concealed Ore Body Exploration--As the Huize Super-Large Lead-Zinc Deposit an exemple

1 Geological Background of Minerlization or Geologic Setting The northeast of Yunnan1 Pb-Zn-Ag-Ge polymetallic ore district is an important part of the southwestern margin of the Yangtze block Sichuan-Yunnan-Guizhou

MAGMATISM AND TECTONO-MAGMATIC EVOLUTION OF JINNING CYCLE OF EASTERN KUNLUN OROGENIC BELT

The exposed area of igneous rocks in East Kunlun Mountains is very large and they made a magmatic arc belt broad in scale. The intrusive rocks are mainly of Hercynian—Indo\|Sinian cycle and less of Caledonian and Yanshanian cycle [1～2] . During the geological mapping of 1∶250000 of Donggeicuonahu area, we firstly found the evidence of intrusive rock of Jinning cycle. Intrusive rocks of Jinning cycle, whose exposed area is about 30km, are located in Waliaoga\|Shaxiong area among East Kunlun magmatic arc belt and are composed of two intrusive bodies. The rock types of Jinning cycle are mainly trondjemite and tonalite. Their wall rocks are Baishahe Group of Paleo\|Proterozoic and was intruded by Hercynian-Indo\|Sinian cycle granodiorite . The wall rock types are mainly banded amphibolite,biotite\|plagioclase schist,leptynite,leptite,banded marble and mica\|schist , their metamorphic condition is overall middle amphibole facies , partly granulite facies , tectonic deformation was mainly of flowage fold and flowage shear in middle and deep levers. Although intrusive rocks of Jinning cycle had undergone intensive metamorphism and deformation, they also preserve the intrusive appearance and are uniform in field. We can see intrusive contacted with wall rock or infolded the basic inclusions. Gneissosity is very common in intrusive rocks of Jinning cycle. Even though intensive metamorphism and deformation lead to interlude between intrusive body and wall rock, most wall rock exists in intrusive rocks as giant roof or inclusions in general, we can see intrusive contacted between intrusive body and wall rock locally. Intrusive rocks are hoar color, meso\|coarse grain lepido\|granoblastic texture , minerals are mainly plagioclase evidence to study the forming and evolution of orogeny of Jinning and Caledonian cycle.

Tectono-Thermal Evolution, Hydrocarbon Filling and Accumulation Phases of the Hari Sag, in the Yingen-Ejinaqi Basin, Inner Mongolia,Northern China

This work restored the erosion thickness of the top surface of each Cretaceous formations penetrated by the typical well in the Hari sag, and simulated the subsidence burial history of this well with software BasinMod. It is firstly pointed out that the tectonic subsidence evolution of the Hari sag since the Cretaceous can be divided into four phases: initial subsidence phase, rapid subsidence phase,uplift and erosion phase, and stable slow subsidence phase. A detailed reconstruction of the tectonothermal evolution and hydrocarbon generation histories of typical well was undertaken using the EASY R% model, which is constrained by vitrinite reflectance(R) and homogenization temperatures of fluid inclusions. In the rapid subsidence phase, the peak period of hydrocarbon generation was reached at c.a.105.59 Ma with the increasing thermal evolution degree. A concomitant rapid increase in paleotemperatures occurred and reached a maximum geothermal gradient of about 43-45℃/km. The main hydrocarbon generation period ensued around 105.59-80.00 Ma and the greatest buried depth of the Hari sag was reached at c.a. 80.00 Ma, when the maximum paleo-temperature was over 180℃.Subsequently, the sag entered an uplift and erosion phase followed by a stable slow subsidence phase during which the temperature gradient, thermal evolution, and hydrocarbon generation decreased gradually. The hydrocarbon accumulation period was discussed based on homogenization temperatures of inclusions and it is believed that two periods of rapid hydrocarbon accumulation events occurred during the Cretaceous rapid subsidence phase. The first accumulation period observed in the Bayingebi Formation(Kb) occurred primarily around 105.59-103.50 Ma with temperatures of 125-150℃. The second accumulation period observed in the Suhongtu Formation(Ks) occurred primarily around84.00-80.00 Ma with temperatures of 120-130℃. The second is the major accumulation period, and the accumulation mainly occurred in the Late Cretaceous. The hydrocarbon accumulation process was comprehensively controlled by tectono-thermal evolution and hydrocarbon generation history. During the rapid subsidence phase, the paleo temperature and geothermal gradient increased rapidly and resulted in increasing thermal evolution extending into the peak period of hydrocarbon generation,which is the key reason for hydrocarbon filling and accumulation.