内蒙古阿拉善北部杭乌拉地区圆包山组时代、沉积特征及大地构造意义

通过阿拉善北部杭乌拉地区圆包山组碎屑锆石峰值年龄(420±3 Ma和419.6±3.6 Ma)以及圆包山组底部层位发育的笔石、头足类化石,认为圆包山组形成时代并非早志留世,而是泥盆纪.圆包山组中发育的大量沉积构造及其岩性特征,表明了圆包山组为典型的半深海-深海浊积岩沉积,但鲍马序列发育不完整,主要有AE、ABE、ADE和ABDE等序列组合,并划分了内扇、中扇和外扇三个沉积亚相.研究区位于阿拉善地区北部,属于西伯利亚板块南缘部分,是研究古亚洲洋闭合时间的关键部位.早古生代硅质岩岩石特征表明,研究区在早古生代处于一个被动大陆边缘的稳定大地构造背景.自晚古生代开始,研究区的大地构造活动性开始增强,逐渐由被动大陆边缘转变为活动大陆边缘,并形成了巨厚的浊积岩.根据浊积岩中槽模、沟模等沉积构造确定了物源区为研究区北部的西伯利亚板块,并根据浊积岩岩性、沉积特征以及砂岩地球化学特征的研究,认为研究区晚古生代早期的浊积岩形成于西伯利亚板块南缘的活动大陆边缘,并同时受岛弧作用的影响,导致浊积岩具有岛弧物源区属性.结合圆包山组中碎屑锆石特征及其年龄可以进一步确定圆包山组物源区位于研究区北部Gobi-Altai构造带.     

浊积岩地层中金矿床地质地球化学特征成因机制及找矿勘探标志

通过对浊积岩中金矿床地质特征、地球化学特征及成因的全面论述,综合国外一些主要的比较典型的浊积岩型金矿床,指出该矿床的找矿标志。     

川西藏东地区金矿床类型与特提斯地质演化的关系

川西藏东地区在大地构造位置上处于欧亚板块和印度板块结合部位的特提斯构造域东段。自早古生代以来，区内曾经历过多期次的构造岩浆活动，为金的成矿作用提供了十分有利的成矿条件。区内金矿床的主要类型有：火山成因块状硫化物型金矿床、层控型金矿床、浊积岩型金矿床、岩浆期后热液型金矿床、矽卡岩型金矿床、斑岩型金矿床、剪切带型金矿床。     

我国几个地区浊积岩系的特征

近年来,由于找寻沉积矿床、研究沉积环境和大地构造的需要,浊积岩(在构造意义上称为复理石)的研究有相当快的发展。作者对东北某地早第三纪浊积岩、秦岭中段三迭纪浊积岩和浙西奥陶纪浊积岩进行了野外观察和室内工作。本文就它们的识别特征、沉积环境和构造环境进行概要的讨论,可能对区测填图和普查找矿等方面工作有所俾益。     

鄂尔多斯盆地黄陵地区上三叠统延长组长7、长6油层组浊积岩沉积特征及地质意义*

利用岩心观察、薄片鉴定和粒度分析等方法,对鄂尔多斯盆地黄陵地区上三叠统延长组长7、长6油层组浊积岩沉积特征与油气地质意义进行了研究。研究结果表明,浊积岩主要为长石砂岩,以棱角状—次棱角状为主,粒度具有典型的浊流沉积特征。沉积构造可见泥底构造、同生变形构造、粒序递变层、鲍玛序列等。最常见的鲍玛序列有ABC型、AB型、ADE型、AE型、CDE型和A段叠置型,具备浊积岩的典型特点。识别出薄层浊积岩和中厚层浊积岩,其属于三角洲前缘滑塌成因,可分为中心微相和边缘微相。浊流砂体是半深湖—深湖区发育的良好储集体,其分布区可作为重要的油气勘探区。     

西藏冈底斯构造带侏罗纪浊积岩特征及构造环境判别

侏罗系浊积岩在冈底斯构造带多个沉积分地中均有分布，以发育较为典型的浊积岩鲍马序列为特征 ，可划分为近源砂质浊积岩、远源细屑浊积岩、碳酸盐浊积岩和滑塌角砾岩等4种主要浊积岩类型。论文对泥质浊积岩的主元素和微量元素地球化学特征进行了研究，在构造环境判别图上投均落入活动大陆边缘区，稀土分布曲线呈近水平状，负Ce异常不明显，显示出冈底斯构造带侏罗纪浊积岩形成于活动大陆边缘的弧后盆地环境，其物源为沉积盆地两侧有古老变质岩出露和弧火山活动的岛弧带。     

鄂尔多斯盆地西南部上三叠统长6油层组湖底扇特征

通过岩心观测、薄片观察和各种资料的综合分析，对鄂尔多斯盆地西南部上三叠统延长组长6油层组湖底扇的岩石类型、粒度特征、沉积构造等特征进行了详细研究。研究结果表明长6油层组浊积岩的岩石类型为长石岩屑砂岩、岩屑长石砂岩和长石砂岩；浊积砂岩的矿物成分成熟度低，结构成熟度较低，杂基含量高。粒度分析表明其具有典型的浊流特征。沉积构造可见递变粒序、底层面构造、滑塌角砾，且发育鲍马序列；反映了浊积岩具有明显的韵律性和旋回性。识别出薄层浊积岩、中层浊积岩、厚层浊积岩3种类型并分别描述其特征。在此基础上进行了亚相划分，详细描述了各亚相特征，确定了浊积岩分布在庆阳、合水、固城、安置农场地区。浊积岩的形成主要受外界的触发机制、充足的物源供给、古斜坡地形等因素控制。     

北山北带古生代岩浆活动与金矿床的形成

北山地区处于塔里木板块、哈萨克斯坦和西伯利亚板块聚合部位。区内深大断裂纵横交错，岩浆岩发育金矿床(点)星罗棋布，是我国最重要的金矿成矿区之一。     

西秦岭地区晚二叠世—早三叠世沉积相分析和沉积古环境再造

青海省同仁地区处于祁连和秦岭造山带的接合部，构造演化历史悠久。本次工作在该地区隆务河一带发现较好的二叠—三叠系剖面。将该剖面从下而上划分为上二叠统石关组、下三叠统果木沟组和江里沟组，其中江里沟组又进一步划分为下部的浊积岩段和上部的风暴岩段，初步确定了二叠—三叠纪的界线。沉积序列、沉积相和沉积物表明上二叠统石关组和下三叠统果木沟组为一套陆源碎屑浊积岩，下三叠统江里沟组下部为一套不纯的内碎屑浊积岩，而下三叠统江里沟组上部为风暴岩沉积。根据沉积相和火山岩夹层的地球化学特征认为该地区上二叠统石关组和下三叠统果木沟组处于半深海的活动大陆边缘，下三叠统江里沟组早期的浊积岩段处于较稳定的半深海大陆边缘。根据沉积相和遗迹化石，恢复了晚二叠世—早三叠世的海平面变化特征。     

桂西北地区微细浸染型金矿床与构造和岩性关系及成矿作用探讨

桂西北地区主要微细浸染型金矿床具有明显的特征,一是金矿体产于断裂边缘;二是金矿体全部产于浊积岩中。因此构造条件和特定岩性是金矿成矿作用的宏观地质表现,而金矿床的形成则应具备成矿物质来源、矿液通道及成矿场所三个条件。     

广西金牙金矿金的来源探讨

通过桂西北中三叠世沉积盆地中有关碎屑物质来源的沉积环境分析和碎屑源区及沉积区金的地球化学场对比,研究了盆地沉积成岩过程中金的富集的贫化特征,认为金牙金矿区的金来源于中三叠统浊积岩沉积盆地。     

Metallogeny and tectonic development of the tasman fold belt system in tasmania

In western Tasmania, Precambrian sedimentary sequences form the basement for narrow trough accumulations of Eocambrian and younger sequences. The main trough, the meridional Dundas Trough, is flanked to the west by the Rocky Cape region of Precambrian rocks within which major, apparently stratiform, exhalative magnetite-pyrite deposits are intercalated with metabasaltic volcanics and ultramafic bodies.The Eocambrian-Cambrian troughs apparently developed during extension of Precambrian continental crust. Early shallow-water deposition includes thick dolomite units in some troughs. Deepening of the troughs was accompanied by turbidite sedimentation, with minor limestone, and submarine basaltic volcanism with associated minor disseminated native copper. Ultramafic and related igneous rocks were tectonically emplaced in some troughs during a mild compressional phase. They contain only minor platinoids, copper-nickel sulphides and asbestos, but are source rocks for Tertiary secondary deposits of platinoids, chromite and lateritic nickel.In the Dundas Trough, Eocambrian-Early Cambrian rocks are separated by an inferred erosional surface from structurally conformable overlying Middle to Late Cambrian fossiliferous turbidite sequences. The structural conformity continues through overlying Ordovician to Early Devonian terrestrial and shallow-marine stable shelf deposits.A considerable pile of probable Middle Cambrian felsic volcanics accumulated between the sedimentary deposits of the Dundas Trough and the Tyennan region of Precambrian rocks to the east. A lava-dominated belt within the volcanics hosts major volcanogenic massive sulphide deposits, including those of the exhalative type, which in the south are enriched in copper, gold and silver, whereas in the north they are rich in zine, lead, copper, gold and silver. Cambrian movements along faults near the margin of the Tyennan region resulted in erosion of the mineralized volcanics, locally exposing sub-volcanic granitoids. Above the local unconformities occur unmineralized volcaniclastic sequences that pass conformably into Ordovician to Early Devonian shelf deposits. Ordovician limestone locally hosts stratabound disseminated and veined base metal sulphide deposits.Pre-Middle Devonian rocks of western Tasmania differ, for most part, from those in the northeast where deeper marine turbidite quartz-wacke sequences were deposited during the Ordovician and Early Devonian.The Eocambrian to Early Devonian rocks of Tasmania were extensively deformed in the mid-Devonian. The Precambrian regions of western Tasmania behaved as relatively competent blocks controlling early fold patterns. In northeastern Tasmania, folding is of similar age but resulted from movements inconsistent with those affecting rocks of equivalent age in western Tasmania.The final metallogenic event is associated with high-level granitoid masses emplaced throughout Tasmania during the Middle to Late Devonian. In northeastern Tasmania, extensive I-type granodiorite and S-type granite, with alkali-feldspar granites, are associated with mainly endogranitic stanniferous grelsens and wolframite ± cassiterite vein deposits. In contrast, scheelite-bearing skarns and cassiterite stannite pyrrhotite carbonate replacement deposits are dominant in western Tasmania, associated mainly with S-type granites. Several argentiferous lead-zinc vein deposits occur in haloes around tin-tungsten deposits. A number of gold deposits are apparently associated with I-type granodiorite, but some have uncertain genesis.The contrasting regions of western and northeastern Tasmania have probably been brought together by lateral movement along an inferred fracture. Flat-lying, Late Carboniferous and younger deposits rest on the older rocks, and the only known post-Devonian primary mineralization is gold associated with Creta ceous syenite.     

北山洗肠井地区寒武系-中奥陶统浊积岩及其火山-沉积组合特征

北山洗肠井地区,寒武纪表现为由陆缘海向大陆坡、陆基,最后进入半深海沉积环境。晚寒武世地壳曾一度抬升。早奥陶世重复出现大陆坡环境。本文所论及的浊积岩物源区来自南侧古陆,形成于北侧大陆坡和陆基上的浊流作用,构成了相互叠覆的浊积扇--浊积岩系。中奥陶世初地壳不断扩张,位于大陆边缘有大量中基性火山活动。随着海底扩张作用进行,最终形成初始洋壳盆地。     

黑龙江多宝山成矿区金矿成矿规律及找矿方向

通过对黑龙江多宝山成矿区内典型金矿床的地质及地球化学特征的研究和对区域上金矿床（点）的分布特点和成因特征的总结,分析了研究区金矿成矿规律,并明确了找矿方向.研究表明：研究区内金矿床（点）主要受控于NW向和NE向菱（环）形构造,其中以NE向断裂为主,而且由西向东金矿化具有不断加强的趋势.矿体主要赋存于中奥陶世和燕山早期火山岩中,成矿物质主要来源于燕山期岩浆岩及其围岩,成矿流体主要来源于大气降水,流体包裹体均一温度均值在133~267℃之间,属于浅成中-低温热液矿床.     

湖南地区晚奥陶世桑比期—凯迪期早期沉积特征及沉积模式*

湖南地区地处扬子陆块和华夏陆块之间,根据沉积地层的岩石学特征、古生物特征及其他沉积特征变化,将湖南地区晚奥陶世桑比期—凯迪期早期的沉积相,划分为开阔台地相、浅海陆棚相、深水盆地相和陆架边缘—斜坡相。开阔台地相以沉积“龟裂纹”灰岩和瘤状灰岩为特征,浅海陆棚相转为沉积砂质板岩,板岩并夹有粉砂岩及泥灰岩透镜体。深水滞流盆地发育黑色碳质页岩及含放射虫硅质页岩,沉积厚度很小,代表了一个相对缺氧还原的欠补偿深水环境;陆架边缘—斜坡相则为岩屑石英粉—细砂岩,长石石英粉—细砂岩及砂质板岩、板岩的韵律互层,沉积厚度超过1000m,具浊流沉积特征。晚奥陶世桑比期—凯迪期早期,湖南地区总体表现为由西北和东南方向往中部逐渐变深,湘中南一带为水体最深地区。     

广西田林地区中三叠统深水沉积研究

广西田林地区中三叠统发育一套巨厚的浊流沉积。本文以实测剖面为基础,结合前人研究成果,对研究区岩相及相组合类型进行详细的研究。结果表明,研究区共识别出6种岩相类型,各种岩相构成3种主要的岩相组合类型:相组合1以砂质碎屑流沉积占主导地位,代表了近端水道沉积;相组合2以典型的浊流沉积为主,代表了远端水道沉积;相组合3以远源浊流沉积为主,代表了水道近端朵体沉积。在此基础上,结合构造背景、物源及区域浊流相分布等因素,建立了研究区中三叠统深水沉积模式。     

扬子地块西北缘及西南缘卡林型金矿的有机质地质地球化学

扬子地块西北缘，西南缘卡林型金矿床的有机碳含量为０．０５％－８．７３％。含金建造形成的环境不同，其改造成的金矿床的有机碳含量不同；矿化主岩的岩性不同，基有机碳的含量不同。由浊积岩型含金建筑改造成的卡林型金矿床，其干酪根属Ⅱ型酪根，原始有机母质属还原环境沉积的海相菌藻类生物演化成的腐泥型有机质。     

The Wyoming gold deposits: volcanic-hosted lode-type gold mineralisation in the eastern Lachlan Orogen,Australia

The eastern Lachlan Orogen in southeastern Australia is noted for its major porphyry–epithermal–skarn copper–gold deposits of late Ordovician age. Whilst many small quartz vein-hosted or orogenic lode-type gold deposits are known in the region, the discovery of the Wyoming gold deposits has demonstrated the potential for significant lode-type mineralisation hosted within the same Ordovician volcanic stratigraphy. Outcrop in the Wyoming area is limited, with the Ordovician sequence largely obscured by clay-rich cover of probable Quaternary to Cretaceous age with depths up to 50 m. Regional aeromagnetic data define a north–south trending linear belt interpreted to represent the Ordovician andesitic volcanic rock sequence within probable Ordo-Silurian pelitic metasedimentary rocks. Drilling through the cover sequence in 2001 to follow up the trend of historically reported mineralisation discovered extensive alteration and gold mineralisation within an andesitic feldspar porphyry intrusion and adjacent volcaniclastic sandstones and siltstones. Subsequent detailed resource definition drilling has identified a substantial mineralised body associated with sericite–carbonate–albite–quartz–(±chlorite ± pyrite ± arsenopyrite) alteration. The Wyoming deposits appear to have formed as the result of a rheological contrast between the porphyry host and the surrounding volcaniclastic rocks, with the porphyry showing brittle fracture and the metasedimentary rocks ductile deformation. The mineralisation at Wyoming bears many petrological and structural similarities to orogenic lode-style gold deposits. Although the timing of alteration and mineralisation in the Wyoming deposits remain problematic, a relationship with possible early to middle Devonian deformation is considered likely.     

黑龙江省多宝山-宽河成矿带Cu-Au成矿规律与成矿预测

黑龙江省多宝山-宽河成矿带铜金矿产十分丰富.区内于早奥陶世初形成的"四隆四拗"构造格局控制了以后各地质时期地层、岩浆演化及矿产的分布.通过对矿带成矿地质背景、物化探异常、典型矿床特征的分析与归纳,总结了铜金成矿规律、成矿条件与找矿标志,预测出9个找矿重点靶区.     

Ordovician Intrusive-related Gold-Copper Mineralization in West-Central New South Wales, Australia

Three major types of Ordovician intrusive-related gold-copper deposits are recognized in central-west New South Wales, Australia: porphyry, skarn and high sulphidation epithermal deposits. These deposits are mainly distributed within two Ordovician volcano-intrusive belts of the Lachlan Fold Belt: the Orange-Wellington Belt and the Parkes-Narromine Belt. Available isotopic age data suggest that mineralization of the three types of deposits is essentially coeval with the Ordovician intrusive rocks (480-430 Ma).Porphyry gold-copper deposits can be further divided into two groups. The first group is associated with monzonite showing shoshonitic features, represented by Cadia and Goonumbla. The second group is associated with diorite and dacite, including the Copper Hill and Cargo gold-copper deposits. Gold skarn is associated with Late Ordovician (430-439 Ma) monzonitic intrusive complexes in the Junction Reefs area (Sheahan-Grants, Frenchmans, and Cor-nishmens), Endeavour 6, 7 and 44, Big and Little Cadia