河北丰宁隐爆角砾岩型银多金属矿床地质特征   总被引：1，自引：0，他引：1  

梁俊红  巩恩普  姚玉增  杨洪英  崔显德 《地质找矿论丛》2007,22(1):48-51

河北丰宁银多金属矿床赋存于隐爆角砾岩体中,发育一组典型低温热液矿物组合的围岩蚀变,矿化为典型低温热液成因的黄铁矿-闪锌矿-方铅矿-黄铜矿硫化物组合;控矿隐爆角砾岩划分为震裂花岗岩相、震碎花岗岩相、熔浆角砾岩相和气爆角砾岩相4类;宏观、微观研究认为其中的硅质角砾由4次喷发作用形成;气爆形成的萤石化可确定赋矿空间的分布规律.  相似文献   

丰宁银矿岩体控矿规律及其意义     

姚玉增  巩恩普  刘海波  梁俊红 《地质与勘探》2007,43(2):45-49

丰宁银矿为与隐爆作用有关的银矿床,是近年来冀北地区发现的重要矿床类型,工业矿体的产出严格受隐爆角砾岩体控制,具体表现为矿体多于熔浆角砾岩与震碎角砾岩的内接触带产出,矿体厚度和工业矿体银的品位也受角砾岩体控制.该规律对矿床的深部矿化远景评价及该区找矿均具有一定的指导意义.  相似文献   

内蒙古虎拉林金矿矿化富集规律和找矿远景评价     

丁清峰  孙丰月  梁海军 《世界地质》2007,26(4):397-402

通过对虎拉林金矿构造控矿规律研究，认为矿区占绝对优势的浸染状矿化主要受角砾岩筒构造控制，矿化不均匀，矿体形态不规则；通过分析该角砾岩筒内角砾岩的特点，结合一般浅成、半浅成角砾岩筒的垂向分带规律，推测该角砾岩筒已剥蚀到了中下部。采用因子分析的方法，确定了该金矿的原生晕轴向分带规律，矿区深部存在着强尾晕异常叠加前缘晕异常的现象，推测深部存在隐伏矿化。由此可见虎拉林金矿总体剥蚀程度较大，但深部还存在着一定的找矿远景。  相似文献   

流体动力角砾岩分类及其地质意义   总被引：1，自引：0，他引：1  

汪劲草  彭恩生  孙振家 《吉林大学学报(地球科学版)》2000,30(1):18-23

根据流体产生异常高压,并在一定条件下分别发生爆发作用、流化作用及水压作用原理,认为从爆发作用到水压作用可分别形成爆发角砾岩系列、流化角砾岩系列及水压角砾岩系列。研究了上述三类流体动力角砾岩的相互关系、鉴别标志及亚类划分。指出异常高压流体在一定条件下既可向增压方向发展,也可向降压方向演化,并以研究实例说明流体动力角砾岩系列岩石的地质作用过程包括爆发作用、流体作用及水压作用三个阶段之一或二或三。  相似文献   

山东平邑卓家庄金矿金品位的分形结构特征及意义   总被引：8，自引：0，他引：8  

曾庆栋  郑晓廷 《地质与勘探》2000,36(3):43-45,47

卓家庄金矿为隐爆角砾岩型金矿床,主要矿石类型可分为４种：矿浆胶结隐爆角砾岩矿石、热液胶结隐爆角砾岩矿石、熔浆胶结隐爆角砾岩矿石、凝灰质胶结隐爆角砾岩矿石。金品位分形结构研究表明,该矿床具有多次分形结构及规律性变化特点,反映了多次矿化叠加的特点,并预示了深部矿化的存在。  相似文献   

Fluids double-fracturing genetic mechanism and mineralization of gold-copper of the breccia pipe at Qibaoshan in Shandong Province   总被引：9，自引：0，他引：9  

XU Xingwang  CAI Xinping  QIN Dajun  WANG Jie  LIANG Guanghe  Zhang Xiaoyun  LIU Lijin 《中国科学D辑(英文版)》2000,43(2):113-121

After studying the characteristics and special texture of the fluidogenous tectonics, mineral assemblage in the cemented vein between breccia and their special distribution, and stress analyzing the joint structures in and around the breccia pipe, it is found that the observed phenomena are caused by a new tectonic dynamic mechanics of fluid—double-fracturing caused by temperature and pressure of fluids and pulsating expansion. Under the actions of thermal stress and the pressure of fluids, thermal cracks and joints that developed along parts of the thermal cracks formed systematically in the rocks. Under these conditions, up-arching fracture zones that pulsatively expanded upward and cylindrical pressing breccia body were formed. Rocks at the peak of the pyramidal fractures zone break down instantly. Where the difference between pressure of fluids and the overburden pressure exceeded greatly the competence of the rocks, fluid junctions occurred and the velocity of the fluid flow increased as a result. Explosive body expanded upward in the shape of an inverse cone, cone-like explosive breccia body and cover-like shattering breccia body located on the upper part of the breccia pipe were ultimately formed. Gold-rich fluids were enriched and mineralized near the boiling surface in the lower part of the inverse cone-like explosive breccia body where temperature and pressure decreased rapidly, while copper-rich fluids were enriched and mineralized in the junction area where temperature and pressure were relatively high.  相似文献   

Puziwan Gold Deposit in Shanxi, China: A Special Linear Cryptoexplosive Breccia Type Gold Deposit   总被引：1，自引：0，他引：1  

YAN Fengzeng Gold Headquarters  State Economic  Trade Commission  P.O. Box:  Beijing 《《地质学报》英文版》2000,74(3)

The Puziwan gold deposit is a special linear cryptoexplosive breccia type deposit found in northeastern Shanxi, China, in recent years. The deposit is located in a secondary metallogenic. belt of the most famous Au-Ag polymetallic metallogenic belt along the north margin of the North China platform. The secondary metallogenic belt is a synmagmatic tension-shear fault-fracture belt of ENE linear trend. The Indosinian cryptoexplosive breccia body, quartz monzonitic porphyry (beschtauite breccia), quartz monzonite (243.7 Ma, K-Ar), Yanshanian granite-porphyry (105±6 Ma, Rb-Sr) and orebodies mostly occur as dykes or veins and short lenses along the structural fracture belt. The orebodies are emplaced in the fractured cryptoexplosive breccia body in the tectonomagmatic belt and their attitude is consistent with that of the breccia body. The orebodies have two types: one is shallow-seated thick and big ones, which are short-lenticular in plan and wedge-shaped in cross section, shallow buried, large in size a  相似文献   

香炉碗子金矿区次火山岩及其地球化学特征     

冯守忠 《地质与资源》2000,9(3):155-159

香炉碗子金矿区分布的次火山岩是由花岗质岩浆沿东西向脆-韧性剪切带上升到地壳浅部隐爆而成,隐爆角砾岩体与霏细岩脉来自同一岩浆源,为同一岩浆活动不同演化阶段的产物,隐爆角砾岩体(脉)、霏细岩脉在时间上、空间上、成因上与金矿形成关系密切.稀土元素、微量元素、同位素等地球化学特征显示出成矿物质和成矿热液与隐爆角砾岩、霏细岩同源,成岩与成矿是同一岩浆作用不同阶段的产物.东西向脆-韧性剪切带内隐爆角砾岩体(脉)、霏细岩脉的存在是区内重要的找矿标志.  相似文献   

The metahyaloclastitic matrix of a unique metavolcanic block reveals subduction in the Somozas Mélange (Cabo Ortegal Complex,NW Iberia): tectonic implications for the assembly of Pangea          下载免费PDF全文

I. Novo‐Fernández  A. Garcia‐Casco  R. Arenas  R. Díez Fernández 《Journal of Metamorphic Geology》2016,34(9):963-985

The allochthonous Cabo Ortegal Complex (NW Iberian Massif) contains a ~500 m thick serpentinite‐matrix mélange located in the lowest structural position, the Somozas Mélange. The mélange occurs at the leading edge of a thick nappe pile constituted by a variety of terranes transported to the East (present‐day coordinates; NW Iberian allochthonous complexes), with continental and oceanic affinities, and represents a Variscan suture. Among other types of metaigneous (calcalkaline suite dated at 527–499 Ma) and metasedimentary blocks, it contains close‐packed pillow‐lavas and broken pillow‐breccias with a metahyaloclastitic matrix formed by muscovite–paragonite–margarite–garnet–chlorite–kyanite–hematite–epidote–quartz–rutile. Pseudosection modelling in the MnCNTKFMASHO system indicates metamorphic peak conditions of ~17.5–18 kbar and ~550 °C followed by near‐isothermal decompression. This P–T evolution indicates subduction/accretion of an arc‐derived section of peri‐Gondwanan transitional crust. Subduction below the Variscan orogenic wedge evolved to continental collision with important dextral component. Closure of the remaining oceanic peri‐Gondwanan domain and associated release of fluid led to hydration of the overlying mantle wedge and the formation of a low‐viscosity subduction channel, where return flow formed the mélange. The submarine metavolcanic rocks were deformed and detached from the subducting transitional crust and eventually incorporated into the subduction channel, where they experienced fast exhumation. Due to the cryptic nature of the high‐P metamorphism preserved in its tectonic blocks, the significance of the Somozas Mélange had remained elusive, but it is made clear here for the first time as an important tectonic boundary within the Variscan Orogen formed during the late stages of the continental convergence leading to the assembly of Pangea.  相似文献   

内蒙古自治区额济纳旗呼伦西白金矿成矿地质条件及找矿模式     

杨富林  娄晨  刘雁青  李万忠  徐海山 《西北地质》2011,44(1):61-68

额济纳旗呼伦西白金矿床位于呼伦西白-珠斯楞反＂S＂型弧形构造的西端,北西向断裂规模较大,既是主要的控岩、控矿构造,也是热液活动的主要通道;后期叠加的北东向次级构造（与次火山岩活动或岩体的深部隐爆作用有关）是本区重要的储矿构造。矿体赋存在侏罗纪斑状黑云母花岗岩、正长斑岩内或与地层接触的内外带的不同构造部位,成矿物质主要来源于该期次火山岩活动,属于岩浆期后热液碎裂蚀变型、次火山岩型（或岩浆隐爆角砾岩型）金矿床。矿区内已发现的13条金矿脉产出环境可分为两种类型：一种是岩体内部或与围岩的内接触带,另一种是外接触带中的破碎带（或薄弱带）。与金矿形成关系密切的蚀变主要为硅化、黄铁矿化、黄铜矿化,含金品位与这些金属硫化物（或其氧化物）的含量呈正相关关系。在分析矿床的成矿地质条件的基础上,初步建立了该矿床的成矿模式,总结了综合找矿标志。  相似文献