共查询到20条相似文献，搜索用时 15 毫秒
1.
2.
Deposits of Ni–Cu–Co–(PGE) sulfide often occur in association with small differentiated intrusions that reside within local transtensional spaces in strike-slip fault zones. These faults often develop in response to incipient rifting of the crust and the development of large igneous provinces due to far-field stresses generated by plume-induced continental drift. We review the geology of a number of large and small nickel sulfide deposits and the associated intrusions, and show that the geometry of the host intrusion and localization of the mineral zones can be classified into three main groups. Further, we show that the morphology of each is controlled by space created in response to deformation on structures.One group of intrusions has the plan shape of an asymmetric rhomboid with the long axis sub-parallel to a fault zone, and contacts which have often been structurally modified during and/or after emplacement of the magma. The typical cross section is a downward-closing cone shape with curved walls and often a dyke-like keel at the base. This morphology is found in the Ovoid and Discovery Hill Zones of the Voisey's Bay Deposit (Canada), the Jinchuan, Huangshan, Huangshandong, Hongqiling, Limahe, Qingquanshan, and Jingbulake (Qingbulake) Intrusions in China, and the Eagle and Eagle's Nest deposits in the USA and Canada, respectively.A second group of deposits is associated with conduits within dyke and sheet-like intrusions; these deposits are often associated with discontinuities in the dyke which were created in response to structural controls during emplacement. Examples include the Discovery Hill Deposit and the Reid Brook Zone of the Voisey's Bay Intrusion, where there are plunging domains of thicker dyke which control the mineralization inside the dyke, and thin discontinuous segments of the dyke which are associated with structurally controlled mineralization in the surrounding country rock gneisses. The Oktyabrysk, Taimyrsk, Komsomolsk, and Gluboky Deposits in the Noril'sk Region of Russia are localized at the base of thicker parts of the Kharaelakh Intrusion which appear to be a conduit that follows synformal features in the country rocks located west of the Noril'sk–Kharaelakh Fault. Other examples of dyke-like bodies with both variation in width and the development of discontinuities are the Copper Cliff and Worthington Offset Dykes which radiate away from the Sudbury Igneous Complex (Canada). The distribution of ore bodies in these Sudbury Offset Dykes is principally controlled by variations in the thickness of the dyke, interpreted to reflect the presence of conduits within the dyke.A third group of mineralized intrusions located within structural corridors have the geometry of oblate tubes; examples include Kalatongke in China, Northeastern Talnakh and Noril'sk 1 in Russia, Babel–Nebo in Australia, and Nkomati in South Africa. Sometimes these oblate tube-like intrusions form in bridging structures between larger intrusions hosted in the more significant structures. Examples include the Tamarack Intrusion in Minnesota, USA, and the Current Lake Complex in Ontario, Canada, both of which contain magmatic Ni–Cu sulfide mineralization.In all of these deposits, the intrusions appear to be open system magma pathways, and so the term “chonolith” can be applied to describe them as a group. All of these intrusions are characterized by a high ratio of sulfide/silicate; there are 1–3 orders of magnitude more sulfide in the intrusion than the magma contained in the intrusion is capable of dissolving. The formation of these deposits is considered to have taken place in open system magma conduits. It is possible that the metal tenor of the sulfides were upgraded by equilibration of successive batches of silicate magma passing through the conduit, and equilibrating with a stationary pool of magmatic sulfide. At Voisey's Bay there appears little doubt that the sulfides were injected through a conduit dyke into higher level magma chambers. A similar model has been proposed for the formation of the deposits at Jinchuan and Noril'sk–Kharaelakh. Economically significant nickel sulfide deposits that tend to be high in Ni tenor, are often related to the late injection of magma that form distinct parts of the intrusion, and the localization of mineralization tends to be related to changes in the geometry of the magma chamber. Strongly deformed and metamorphosed komatiite-associated deposits (e.g. Pechenga, Thompson, and the Yilgarn komatiite associations) appear to be the remains of open system magma conduits which are now represented by segmented and boudinaged ultramafic bodies as a result of more than 4 phases of post-emplacement deformation.LIP activity at craton margins has long been recognized as a key control on the genesis of magmatic sulfide deposits; we show that the principal regional controls of strike-slip tectonics underpin the local geometry of the intrusions, and we provide an explanation for why so many of the global nickel sulfide ore deposits are associated with intrusions that share common morphologies and characteristics. This model provides a framework for more detailed structural investigations of nickel sulfide deposits, and it is a predictive framework for mineral exploration. 相似文献
3.
宁夏贺兰山北段牛头沟金矿地质地球化学特征和矿床成因探讨 总被引：1，自引：0，他引：1
牛头沟金矿位于华北陆块鄂尔多斯地块西缘贺兰山裂陷北段之基底杂岩带,赋矿地层为一套下元古界宗别立群第二亚群(Pt1z2)中的中-深程度变质岩系。矿体受深大断裂(正义关断裂)的次级主断裂(F1)控制;该控矿断裂构造(F1)形成于海西-印支期,经历早期逆冲挤压,晚期局部引张破裂的多期活动阶段,矿化作用主要形成于主断裂(F1)张性破裂阶段,矿化早期主要表现为强烈硅化,矿化晚期硅化岩破裂被主成矿流体充填-交代形成蚀变岩型金矿,为矿区主要成矿类型。石英脉型金矿形成于与主断裂有联系的次级张裂隙中。二者反映矿床类型不同,但成矿作用是一致的。即在动力作用下产生的变质热液在构造的有利部位或裂隙中交代-充填成矿。硫化物硫同位素组成和矿物流体包裹体研究表明,该蚀变岩型金矿成矿物质和成矿流体来源具多源性。 相似文献
4.
通过对湖南郴县枞树板脉状铅锌（银）矿床控矿（含矿）断裂构造的详细研究,认为控矿断裂构造内部具有弧形断层面及其所夹持的构造透镜体组成结构形式;控矿断裂的形态、产状、规模和分布控制矿化带及矿体的形态、产状、规模和分布;控矿断裂的结构形式和力学性质影响并控制矿化形式和矿化富集程度;富矿体产在控矿断裂内部弧形断面较为发育且又较破碎的部位;富矿体单体产出特征是呈不等轴透镜体状,长轴向南西侧状,侧伏角５５°～６０°,长（斜高）与宽之比近于２∶１,富矿体组合规律是斜列状,自北东向南西逐个降低出露标高,轴线向南西侧伏,侧伏角１５°～２０° 相似文献
5.
6.
7.
8.
I. R. Prokopyev A. A. Kravchenko A. I. Ivanov A. S. Borisenko A. V. Ponomarchuk A. I. Zaitsev E. A. Kardash A. A. Rozhkov 《Russian Journal of Pacific Geology》2018,12(1):34-45
The Dzheltula alkaline massif is located in the Tyrkanda ore region of the Chara–Aldan metallogenic zone of the Aldan–Stanovy Shield (South Yakutia). The region contains separate placer gold objects, which are being explored at the present time, and ore-bearing Mesozoic alkaline intrusions, which are weakly studied due to their poor accessibility. The Dzheltula massif (DM) is the largest exposed multiple-ring intrusion within the Tyrkanda ore region; therefore, it is considered as a typical object for geological, petrological, geochronological, and metallogenic studies. The DM consists of five magmatic phases of syenite composition. 40Ar–39Ar dating has established that the crystallization age of the oldest phase, the leucocratic syenite porphyry (pulaskite), is 121.1 ± 1.3 Ma. The crystallization age of the cross-cutting phases represented by syenite–porphyry dikes (laurvikites and pulaskites) ranges from 120.1 ± 2 to 118.3 ± 2.1 Ma. The youngest phase of the massif, trachyte, crystallized at 115.5 ± 1.6 Ma. According to the mineralogical and geochemical studies, two types of ore mineralization, namely gold and uranium–thorium–rare-earth (U–Th–REE), are established within the DM. The gold mineralization was found in the quartz–chlorite–pyritized metasomatites. It is confined to the NNE- and NNW-trending fault zones and coincides with the strike of the syenite porphyry dike belt. Uranium–thorium–rare-earth mineralization has been established in the quartz–feldspathic metasomatites localized in the outer contact of the massif. The juxtaposition of mineralization of different types in some zones of the Dzheltula syenite massif significantly increases the ore potential of the studied object within the Tyrkanda ore region. 相似文献
9.
罗布莎铬铁矿区成矿构造条件的研究 总被引：2，自引：0，他引：2
矿区位于藏南超基性岩带罗布莎超基性岩体,主要矿床成因类型有:岩浆晚期熔离矿床和正岩浆期矿床。后者未构成具工业价值铬铁矿体,前者为矿区主要矿床成因类型。本文仅探讨岩浆晚期熔离矿床的成矿构造条件。 相似文献
10.
《International Geology Review》2012,54(5):874-883
The great Dzhungar fault zone extends across the border between Sinkiang and the U.S.S.R., separating the intermontane depression of the Balkhash region and Dzhungaria from the mountain uplift of Dzhungar Alatau. The length of the fault is about 5OO km and the width is several kilometers. On airphotos the fault appears straight, but on a regional scale it is slightly arcuate. The fault is characterized by prolonged development of both vertical and horizontal (right lateral) displacement starting in middle Paleozoic and continuing intermittently to the present. Also during intervals of time, dislocation penetrated the entire thickness of the earth's crust as far as the peridotite layer permitting ultrabasic intrusion. Acidic intrusions, volcanics, and hydrothermally altered rocks also occur along parts of the fault zone. The fault strongly cuts obliquely across Hercynian folding and also alpine dome-block structures. The fault controlled and localized distinctive formations throughout most of post-Precambrian time. A summary of the geologic history of the fault is presented.—L. T. Grose 相似文献
11.
安徽铜陵矿集区斑岩型铜钼金矿床地质特征及成矿背景 总被引：4，自引：3，他引：1
铜陵矿集区以发育大型和为数众多的矽卡岩型矿床而闻名于世,而近年来作为该区找矿的重要成果和突破则是斑岩型矿床和矿化的陆续发现。本文以铜陵矿集区3个代表性斑岩型矿床为研究对象,在详细的野外地质调查和室内显微观察研究的基础上,开展了较为系统的矿床地质和地球化学研究,阐述了斑岩型矿床的地质特征,确定了含矿侵入岩体的地质和地球化学特征,分析了矿床蚀变特征和流体包裹体特征,探讨了成岩成矿的大地构造背景,并与世界典型斑岩型矿床进行了对比。研究表明,铜陵矿集区斑岩型铜钼金矿床通常发育于含矿岩体的围岩或盖层为砂岩、砂页岩或硅质岩的条件下,含矿岩体为富碱低镁高钾准铝质钙碱性系列中浅成侵入岩体,具有与埃达克岩一致的地球化学特征;与世界典型斑岩型矿床含矿岩体对比,岩体侵位较深,有些矿区多期多相特征不明显;含矿岩体发育钾硅酸盐化、黄铁绢英岩化、青磐岩化等热液蚀变且有一定的分带性,但各矿床蚀变特征略有不同;矿床矿石矿物中富气相、富液相和含子晶多相包裹体共生,流体包裹体均一温度和盐度演化特征显示具有岩浆作用控制的高温热液型矿床特征。结合区域构造演化,作者确定铜陵矿集区斑岩型矿床属大陆环境斑岩型矿床,成矿作用发生于陆内造山作用由挤压向拉张转化的动力学背景之下,斑岩型矿床与矽卡岩型矿床及热液脉状矿床共同构成受统一的岩浆热液系统控制的矿床系列。 相似文献
12.
云南巍山笔架山锑矿床成因 总被引：1，自引：0，他引：1
矿区褶皱和断裂相互重叠交错,为含矿热气液的运移提供了导矿及储矿构造。微量元素测定,确定上三叠系地层为锑的矿源层,矿体严格受层位控制,三合洞组灰岩破碎带为含矿层位,是找矿主要标志。依据矿床产出特点及物理化学条件,确认该矿床属中低温热液富集层控矿床。 相似文献
13.
西湾铅锌矿床位于长江中下游成矿带中段庐枞矿集区北部、NE与近EW向基底断裂交会处，成矿条件优越。通过对矿区地质、矿化蚀变、矿体特征及矿石特征等进行分析，认为西湾铅锌矿的主要赋矿围岩为中三叠统周冲村组灰岩角砾岩，控矿构造为基底褶皱隆起带、基底断裂及其次级断裂，构造破碎带和“硅钙面”对铅锌矿体的控制明显。NE向断裂为导矿构造，其次级断裂及其形成的破碎带和“硅钙面”为容矿构造。根据赋矿围岩、控矿构造及铅锌矿赋存特征，认为西湾铅锌矿床的控矿因素为地层和构造，该矿床为受地层岩性和构造控制的热液充填型铅锌矿床。 相似文献
14.
15.
福建省上杭县罗卜岭斑岩铜钼矿床构造控矿规律研究 总被引：6，自引：0，他引：6
罗卜岭铜(钼)矿区位于紫金山矿田的东北部,是与晚中生代花岗闪长斑岩体有关的隐伏斑岩型铜钼矿床;主要斑岩矿体产于绿泥石化-绢英岩化和(弱)钾化-绢英岩化带中,矿石矿物组合为黄铜矿+辉钼矿;少量过渡类型矿体产于高级泥化带中,矿石矿物组合为蓝辉铜矿+铜蓝+辉钼矿。罗卜岭矿区地表露头含矿裂隙的统计结果显示,罗卜岭成矿晚期的含矿裂隙具有明显的方向性。远离斑岩体的含矿裂隙与其附近的区域构造方位或侵入体走向相近,表明受到北东向区域构造活动控制;而斑岩体西侧露头附近的含矿裂隙呈放射状,主要受到斑岩体侵入作用的影响。深部隐伏矿体则受到区域断裂和花岗闪长(斑)岩侵入体的共同控制,具体表现为:垂向上,以隐伏似斑状花岗闪长岩为中心,由深至浅,矿体铜钼品位比值依次变大,显示了Mo\Cu-Mo\Cu(Mo)的元素垂向分带;平面上,铜、钼元素沿着北东向、北西向断裂和岩体接触带附近有明显富集;斑岩型铜钼矿体主要产于似斑状花岗闪长岩外接触带的花岗闪长斑岩中,形态和产状受到区域北东向断裂或岩体接触带构造影响;蓝辉铜矿体主要产于罗卜岭花岗闪长斑岩外接触带的花岗闪长岩体内,形态和产状受接触带控制。区域构造和斑岩侵入体对斑岩型铜钼矿化有不同的影响,浅部铜、钼矿化受区域断裂构造控制作用明显,而深部矿体主要受花岗闪长(斑)岩体和断裂构造共同控制。区域上北东向背斜构造和北东、北西向断裂构造控制了花岗闪长质侵入岩体的侵位,矿区尺度的断裂构造对斑岩体的就位和成矿作用有一定的影响,罗卜岭花岗闪长斑岩体及其接触带则直接控制了斑岩型矿体的产出,这一规律对紫金山矿田深部和外围隐伏斑岩型矿体的勘查工作具有重要的参考意义。 相似文献
16.
17.
西准噶尔布兰萨拉地区位于谢米斯台-沙尔布提铜多金属成矿带的西段,区内已发现金矿床、金矿点、矿化点数十处,但目前尚无人对区内的金成矿条件进行系统总结和分析,下一步找矿方向不明确。本文在前人工作基础上,通过收集、整理已有的钻探、槽探、化探等资料,结合实地勘察及样品采集等工作,初步梳理出石英脉型和蚀变岩型两种金矿化成因类型。赋矿地层主要为古生界下志留统谢米斯台组,赋矿岩系为火山碎屑岩,岩性以石英脉、硅化凝灰岩等为主。晚志留世中酸性侵入岩与金矿的关系密切。北东向孟布拉克断裂为研究区内主干断裂,为导矿构造,控制着带内金矿的分布及规模,北东向、近东西向、北北东向的第二级次级断裂是主要的成矿、容矿构造。不同方向构造交汇地段、中酸性侵入体发育地段及金地球化学晕圈分布地段是研究区内下一步金矿找矿方向。 相似文献
18.
19.
长江铀矿田位于广东仁化县,是中国华南地区最重要的硬岩型铀矿田。铀矿田内发育北北西（近南北）向含矿构造和北东东向棉花坑断裂及北西西向油洞断裂。棉花坑断裂、油洞断裂与铀成矿的关系涉及到矿田控矿构造格局构建和进一步找矿预测等关键问题。通过精细野外地质调查,重点研究棉花坑断裂、油洞断裂与北北西（近南北）向含矿断裂的相互关系,特别是断裂构造发育的特点和相互配套关系,取得如下认识:棉花坑断裂为脆性断裂破碎带,以未胶结的含有磨圆的花岗岩角砾的构造角砾岩和断层泥为特征,线性构造和负地貌特征明显,属于成矿后压扭性断裂,断错铀矿体和铀矿化带,但位移不大;油洞断裂为脆性破碎带,具有线性构造和负地貌特征,为北北西（近南北）向控矿构造的伴生张扭性断裂,并局部被其后的基性岩脉充填,它不是高级序控矿断裂,仅仅起局部含矿构造作用;油洞断裂带附近的韧性变形不是油洞断裂的连续韧性变形带,而是油洞岩体内小规模、零星不规则、多方向韧性变形的一部分;基于含矿构造呈北北西（近南北）向的展布特征,矿田内进一步的找矿方向不是沿着棉花坑断裂或油洞断裂的方向,而是沿着北北西（近南北）向含矿构造及现有矿化带的走向和倾向深部,在现有矿带间空白区的深部也很可能存在隐伏矿带。 相似文献
20.
热液脉状矿床主要受断裂控制，控制矿脉就位的含矿(赋矿)构造绝大多数是规模比较小的次级断裂或裂隙，而主干断裂普遍被认为是导矿构造或配(运)矿构造，但往往不含矿，甚至没有一点与矿化有关的蚀变痕迹、或成矿流体经过的痕迹。从岩石力学破裂准则看，是最先形成有微孔隙或缺陷存在的微破裂，微破裂逐渐扩展形成小断裂，最后贯通形成主断裂；相关模拟实验也证实存在基底断裂的情况下，盖层破裂的发育过程是最先出现R裂隙、其次是P裂隙、再是D裂隙，最后贯通成具辫状结构的主断裂带。邹家山铀矿床含矿构造是在"X"剪节理基础上发展起来并经持续(递进)变形而形成的"弧形断层面夹透镜状岩块"组合，控制矿带或矿体群的构造是北东东走向、倾向北北西中偏缓倾角、具有左行正断的隐性断裂带。含矿裂隙经历初成、成型和成矿三个阶段演化，成矿后经历邹家山-石洞主断裂贯通和隆升剥露两个阶段演化，最终形成目前的保存状态。 相似文献