首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 814 毫秒
1.
鲁苏西矿床位于刚果(金)加丹加外侧褶皱推覆带,属层控型铜钴矿床。矿床产出于新元古代加丹加超群矿山组还原性地层中,按层序关系分为三层矿体,即坎莫托段底部、白云岩化页岩段底部和刚波夫段底部,矿床受卢非利安造山活动的推覆挤压作用而呈向斜形态。矿石类型分为硫化矿和氧化矿,其中硫化矿主要矿石矿物有黄铜矿、硫铜钴矿、辉铜矿、硫钴矿等,矿化类型主要为浸染状、平行层理细脉状和脉状矿化,前两种矿化为成岩期(821~762 Ma)盆地卤水中的铜钴离子经生物还原作用沉淀形成,后者是由于卢非利安造山期(600~530 Ma)的推覆挤压作用促使早期硫化物再活化、运移并经热化学还原作用形成;氧化矿主要矿石矿物为孔雀石、硅孔雀石、菱钴矿和水钴矿,是在表生期低温(<50°C)流体作用下,经过硫化物氧化、流体酸中和、次生铜钴氧化物沉淀三个过程形成,由于铜钴元素的迁移性差异,形成氧化带上钴下铜的分层矿化特征。  相似文献   

2.
赋存在石墨片岩和大理岩内的山西中条山沉积岩容矿型铜钴矿床,其矿化类型为细脉浸染状和热液脉状,与中非铜矿带的钴矿床非常相似。本文以关键金属钴作为主要研究对象,综述了中条山矿集区钴矿成因研究近年来取得的重要进展。获得以下主要认识:(1)钴富集形成热液脉状矿化发生在造山抬升阶段,时间为~1.82Ga,而不是在沉积成岩阶段直接富集成矿;(2)黄铁矿原位Fe-S同位素揭示硫化有机质页岩是钴成矿的重要矿源层;(3)蒸发岩在造山作用过程中形成的高温、高盐、强氧化性流体是钴释放-迁移的关键介质;(4)热液白云石化导致流体pH升高和石墨片岩“褪色”反应导致流体氧逸度降低促进含钴硫化物的沉淀。基于上述认识,建立沉积-变质两阶段钴富集过程模型解释赋存在变沉积岩内的钴矿成因,它不同于经典的沉积岩容矿型层状铜钴矿床成矿模型。  相似文献   

3.
大同地区相继发现了一系列与侵入岩有关的铜钼矿点和矿化点,布斯拉津铜钼矿化点是在大同地区新发现的岩浆热液脉状铜钼矿化点。首次采用LA-ICP-MS锆石U-Pb测年技术对大同地区布斯拉津含矿黑云母石英二长岩和花岗细晶岩进行锆石U-Pb同位素测年,获得成岩年龄分别为446Ma和449Ma;对辉钼矿中Re-Os同位素进行测试,获得等时线年龄为435±25Ma,表明大同地区成矿作用略晚于成岩作用,岩浆热液铜钼矿化是加里东中期的构造、岩浆活动的产物,成矿物质来源以壳幔混源为主,成矿作用与古亚洲构造域和特提斯构造域的复合演化有关。发生于加里东中期的这一成矿事件,是在俯冲挤压背景下的间歇拉张作用影响下的强烈岩浆活动和成矿作用的产物。  相似文献   

4.
新疆希勒库都克铜钼矿床地质特征和成因探讨   总被引:4,自引:0,他引:4  
希勒库都克为近年来发现的一个以钼为主的铜钼矿床.在对矿床地质背景、矿区地质特征、矿体和矿石特征、矿化阶段和分带、围岩蚀变及矿床地球化学研究基础上,认为希勒库都克矿床以铜-钼组合、细脉浸染状矿化为特征,成矿与中酸性(次火山)斑岩脉有关,围岩蚀变具斑岩矿床的分带特征.成矿物质来自含矿斑岩,成矿流体来自岩浆水和天水混合.成矿温度和盐度较高,属斑岩铜钼矿床成因.辉钼矿Re-Os等时线年龄为(327.1±2.9)Ma.进一步研究表明,该矿床含矿斑岩锆石U-Pb年龄为(329.2±8.2)Ma,SiO2在70.37%~73.46%,K2O在3.65%~3.96%,铝饱和指数(A/CNK)为0.99~1.03,σ为1.48~1.87,属弱过铝质高钾钙碱性系列岩石.矿床产于后碰撞构造环境,在新疆北部这类斑岩铜钼矿床具良好的找矿潜力.  相似文献   

5.
玉勒肯哈腊苏斑岩铜(钼)矿主要赋存于闪长玢岩中,少量在北塔山组火山岩及似斑状石英二长岩中。矿化呈细脉状、细脉-浸染状和浸染状。成矿过程经历了斑岩期、剪切变形期和表生期。矿区发育韧性剪切变形带,中泥盆统北塔山组、下石炭统姜巴斯套组、岩体及矿体均发生了剪切变形作用。沿剪切面发育黑云母和白云母新生矿物。白云母的坪年龄和等时线年龄分别为283.8±1.5Ma和285.4±3.1Ma,黑云母的坪年龄和等时线年龄分别为277.0±2.0Ma和277.0±4.0Ma,在误差范围内基本一致,限定矿区韧性剪切变形时间在早二叠世(284~277Ma),与区域额尔齐斯-玛因鄂博断裂活动时间一致。主要成矿作用形成于斑岩期,成矿时代为中泥盆世(374Ma),早二叠世的韧性剪切变形作用只对铜(钼)矿化进行改造。  相似文献   

6.
西藏色布塔铜钼矿床中辉钼矿Re-Os定年及其成矿意义   总被引:4,自引:0,他引:4  
色布塔铜钼矿床位于冈底斯成矿带北部,具有细脉浸染状矿化,围岩蚀变发育等斑岩型铜钼矿床特征.本文使用电感耦合等离子体质谱仪TJA X-series ICP-MS对色布塔铜钼矿床的花岗斑岩中的辉钼矿进行ReOs同位素定年研究,获得了6件样品的模式年龄为87.52±1.35~88.8±1.26Ma,等时线年龄为88.8±1.5Ma.本文研究成果表明,色布塔铜钼矿成矿时代为晚白垩世早期,属燕山期构造-岩浆活动的产物.  相似文献   

7.
内蒙古白乃庙铜金矿床的成矿时代和成矿构造背景   总被引:20,自引:10,他引:10  
内蒙古白乃庙铜金钼矿床位于华北板块北缘的中亚造山带的温都尔庙加里东期增生带内,其成矿时间、成因类型和构造环境一直存在分歧。为确定成矿时间,作者运用高精度单颗粒激光熔融氩氩法对含矿石英脉中的黑云母和白云母矿物进行了年龄测定。获得黑云母样品22点~(40)Ar/~(39)Ar等时线年龄为396±2 Ma(MSWD=20),白云母样品23点~(40)Ar/~(39)Ar等时线年龄为358±2 Ma(MSWD=11),确证矿床形成于泥盆纪。矿区斑岩等岩浆岩类侵位年龄为428~466 Ma,早于成矿年龄至少40 Ma;赋矿地层白乃庙群形成于1130Ma左右,早于成矿时间约700Ma。如此大的年龄差表明白乃庙矿床不是斑岩型或海底喷流沉积型矿床,而是通过矿床地质和流体包裹体研究所确定的造山型铜金矿床。白乃庙矿床的成矿年龄与赋矿地层白乃庙群的峰期变质作用年龄(384.5±6Ma)基本一致,也与晚志留世-泥盆纪时温都尔庙增生岩浆弧与华北克拉通北缘的碰撞拼贴时间吻合,因此认为白乃庙铜金矿床形成于碰撞造山体制,是世界首例造山型铜矿床。  相似文献   

8.
刘洪微 《地质与勘探》2018,54(4):856-866
KOLWEZI铜钴矿位于刚果(金)-赞比亚铜钴矿带,卢菲利弧外部褶皱推覆构造带西北缘,KOLWEZI复式推覆体上。该矿床主要受Mines亚群及卢菲利造山运动D1阶段褶皱、逆冲推覆、断层及层间断裂控制。矿体呈层状,矿石主要为它形粒状结构,层状、浸染状构造,矿石矿物和脉石矿物按生成序次可以分为四个组合。结合毗邻KOLWEZI的类似矿床的地球化学研究及中非铜矿带的研究成果,认为KOLWEZI铜钴矿床的成矿过程经历了三个成矿期次,其中同成岩期成矿是形成KOLWEZI铜钴层状矿体的主要期次,同造山期矿化使先成层状矿体中的硫化物矿物发生活化、再沉淀,同造山构造活动一定程度上塑造了KOLWEZI铜钴矿床如今的产出状态。分析认为,KOLWEZI铜钴矿应属同成岩层状沉积矿床。  相似文献   

9.
郭文秀  刘建民 《华北地质》2002,25(3):206-213
大横路地区出露地层主要为元古界老岭群大栗子组和珍珠门组的低绿片岩相-高绿片岩相到低角闪岩相的变质岩系,北部有少量英云闪长岩-奥长花岗岩和表壳岩残块.侵入岩主要以燕山期基性-中基性为主.铜钴矿床产于含碳绢云千枚岩中,矿体长360~1400 m,宽95~800 m,厚3~108.7 m,呈层状、似层状、分枝状,矿石以浸染状为主,次为脉状、网脉状.矿床属多期多成因类型,主要受大栗子组地层、北东向断裂构造和变质作用控制,并有岩浆热液的叠加.  相似文献   

10.
大横路地区出露地层主要为元古界老岭群大栗子组和珍珠门组的低绿片岩相-高绿片岩相到低角闪岩相的变质岩系,北部有少量英云闪长岩-奥长花岗岩和表壳岩残块.侵入岩主要以燕山期基性-中基性为主.铜钴矿床产于含碳绢云千枚岩中,矿体长360~1400 m,宽95~800 m,厚3~108.7 m,呈层状、似层状、分枝状,矿石以浸染状为主,次为脉状、网脉状.矿床属多期多成因类型,主要受大栗子组地层、北东向断裂构造和变质作用控制,并有岩浆热液的叠加.  相似文献   

11.
王翠芝  李超 《岩矿测试》2012,31(4):745-752
福建武夷山坪地钼矿为中高温热液型钼矿,产于晚侏罗世钾长花岗岩岩体"层节理"及岩体与下元古界大金山组接触带的南北向断裂中。矿石自然类型主要为硅化岩型(石英脉型)、黄铁绢英岩型、花岗岩型、蚀变构造岩型。矿石构造主要有条带状、浸染状、角砾状、细脉状等构造类型。矿石结构以中粗-中细粒鳞片结构为主,局部呈现厚板状、带状(常常弯曲)。辉钼矿是唯一的矿石矿物。本研究采集坪地钼矿不同矿体、不同产状、不同标高的辉钼矿进行Re-Os同位素测年,得到等时线年龄为(102.9±1.8)Ma,MSWD=2.1,Re-Os模式年龄为(103.70±1.7)Ma~(111.6±1.6)Ma,加权平均值为(107.4±3.3)Ma,MSWD=16。MSWD均较大,说明坪地辉钼矿的成矿具有多阶段性,钾长花岗岩中细脉状、岩体"层节理"中粗脉状和断裂角砾岩带中团块状三种类型的辉钼矿分别是在(111.20±1.7)Ma~(111.60±1.6)Ma、(105.60±1.6)Ma~(107.40±1.6)Ma和(103.70±1.7)Ma三个不同的成矿阶段形成的,成矿时代属早白垩世晚期。这一同位素年龄资料为福建东南沿海浦城—宁德北西向中生代构造-岩浆带中同类矿床的形成演化与指导区域找矿提供了新的地球化学依据。  相似文献   

12.
粤北梅子窝钨锡矿床地质特征及其成矿年龄研究   总被引:10,自引:4,他引:6  
对梅子窝钨锡矿床含矿石英脉进行了Rb-Sr同位素年代学研究,获得石英Rb-Sr等时线年龄为150±5Ma,与前人在同一地区获得的师姑山钨铋矿和石人嶂钨矿含矿石英脉中共生辉钼矿物Re-Os等时线年龄(154~159Ma)在实验误差范围内一致。研究表明,南岭中段始兴地区的钨矿、钨锡矿和钨铋矿的形成时代分布在150~160Ma之间,同属南岭地区中生代大规模成岩成矿作用高峰期的产物。  相似文献   

13.
Eclogite facies mineral assemblages are variably preserved in mafic and ultramafic rocks within the Western Gneiss Region (WGR) of Norway. Mineralogical and microstructural data indicate that some Mg–Cr-rich, Alpine-type peridotites have had a complex metamorphic history. The metamorphic evolution of these rocks has been described in terms of a seven-stage evolutionary model; each stage is characterized by a specific mineral assemblage. Stages II and III both comprise garnet-bearing mineral assemblages. Garnet-bearing assemblages are also present in Fe–Ti-rich peridotites which commonly occur as layers in mafic complexes. Sm–Nd isotopic results are reported for mineral and whole rock samples from both of these types of peridotites and related rocks. The partitioning of Sm and Nd between coexisting garnet and clinopyroxene is used to assess chemical equilibrium. One sample of Mg–Cr-type peridotite shows non-disturbed partitioning of Sm and Nd between Stage II garnet and clinopyroxene pairs and yields a garnet–clinopyroxene–whole-rock date of 1703 ± 29 Ma (I= 0.51069, MSWD = 0.04). This is the best estimate for the age of the Stage II high-P assemblage. Other Stage II garnet–clinopyroxene pairs reflect later disturbance of the Sm–Nd system and yield dates in the range 1303 to 1040 Ma. These dates may not have any geological significance. Stage III garnet–clinopyroxene pairs typically have equilibrated Sm–Nd partitioning and two samples yield dates of 437 ± 58 and 511 ± 18 Ma. This suggests that equilibration of the Stage III high-P assemblage is related to the Caledonian orogeny and is more or less contemporaneous with high-P metamorphism of ‘country-rock’eclogites in the surrounding gneisses. The Sm–Nd mineral data for the Fe–Ti-rich garnet peridotites and for a superferrian eclogite, which occurs as a dyke within the Gurskebotn Mg–Cr-type peridotite, are consistent with a Palaeozoic high-P metamorphism. Finally a synoptic P–T–t path is proposed for the Mg–Cr-type peridotites which is consistent with the petrological and geochronological data.  相似文献   

14.
Gold deposits in the Syama and Tabakoroni goldfields in southern Mali occur along a north-northeast trending mineralised litho-structural corridor that trends for approximately 40 km. The deposits are interpreted to have formed during a craton-wide metallogenic event during the Eburnean orogeny. In the Syama goldfield, gold mineralisation in 9 deposits is hosted in the hanging-wall of the Syama-Bananso Shear Zone in basalt, greywacke, argillite, lamprophyre, and black shale. Gold is currently mined primarily from the oxidised-weathered zone of the ore bodies. In the Syama deposit, mineralisation hosted in altered basalt is associated with an intense ankerite–quartz–pyrite stockwork vein systems, whereas disseminated style mineralisation is also present in greywackes. In contrast, the Tellem deposit is hosted in quartz–porphyry rocks.In the Tabakoroni goldfield, gold mineralisation is hosted in quartz veins in tertiary splay shears of the Syama-Bananso Shear Zone. The Tabakoroni orebody is associated with quartz, carbonate and graphite (stylolite) veins, with pyrite and lesser amounts of arsenopyrite. There are four main styles of gold mineralisation including silica-sulphide lodes in carbonaceous fault zones, stylolitic quartz reefs in fault zones, quartz–Fe–carbonate–sulphide lodes in mafic volcanics, and quartz–sulphide stockwork veins in silicified sediments and porphyry dykes. The several deposit styles in the goldfield thus present a number of potential exploration targets spatially associated with the regional Syama-Bananso Shear Zone and generally classified as orogenic shear-hosted gold deposits.  相似文献   

15.
The Kalguty ore-magmatic system (OMS) contains economic greisen and vein rare-metal-tungsten-molybdenum mineralization. The data on U-Pb zircon (SHRIMP II) age of nine samples of igneous rocks from the Kalguty OMS are accompanied by chemical, ICP-MS, and ICP-AES analyses of the main rock varieties. Porphyritic biotite granite of the main phase of the Kalguty pluton is characterized by the concordant age of 207.5 ± 1.7 Ma (MSWD = 0.034). The concordant age of the leucogranitic dikes pertaining to the East Kalguty Complex is 204 ± 2 Ma (MSWD = 0.65) for elvan and 200.8 ± 1.1 Ma (MSWD = 0.72) for ultrapotassic rhyolite porphyry. The two-mica and muscovite leucogranite of the Eastern stock is significantly younger: 195 ± 2.7 Ma (MSWD = 0.076) and 193.1 ± 2.1 Ma (MSWD = 0.0009). Thus, the Chingadatui Complex (the main phase of the Kalguty pluton) and dikes of the East Kalguty Complex are Late Triassic in age. The two-mica leucogranites of the Eastern, Zhumaly, and other stocks are most likely correlated to the Early Jurassic Alacha Complex of rare-metal granites. The superposition of greisen mineralization on elvan and ongonite dikes may be related to the emplacement of younger, Early Jurassic ore-forming two-mica and muscovite granites. Judging from zircon xenocrysts in granites, the Mesoproterozoic igneous rocks dated at 1.5 Ga and products of erosion of the rocks dated at 1.7 and 2.5 Ga occur in the basement of the Kalguty volcanic-tectonic structure. This is sound evidence for the occurrence of ancient continental crustal blocks in the southwestern part of the Altai-Sayan region.  相似文献   

16.
塔里木西南缘铁克里克地区广泛发育早古生代中酸性侵入岩,本文对其中布雅岩体及其暗色包体进行系统的岩石学、年代学及岩石地球化学研究,确定了岩石成因及其构造属性。LA-MC-ICP-MS锆石U-Pb年代学研究表明,寄主石英二长闪长岩结晶年龄为432.6±2.5 Ma(MSWD=1.5),暗色包体结晶年龄为432.4±6.4 Ma(MSWD=0.031),二者形成时代相同,均为志留纪早期岩浆活动的产物。地球化学特征表明,布雅暗色包体应来源于地幔的部分熔融,而寄主岩石岩浆具有壳源岩浆的性质并经历了幔源岩浆不均匀的混合。野外及岩相学特征均显示暗色包体为铁镁质岩浆注入长英质岩浆快速冷凝形成的,是幔源岩浆底侵下地壳形成的岩浆混合作用的产物。它们是塔里木南缘早古生代碰撞造山作用晚期的岩浆记录。  相似文献   

17.
哈达门沟金矿床地质特征及其形成时代研究   总被引:6,自引:0,他引:6       下载免费PDF全文
哈达门沟金矿床位于华北地台北缘西段,产于太古代乌拉山岩群变质碉系中,矿床以发育一系列含金钾长石-石英脉为特征,这些钾长石-石英脉沿近东西向的韧、脆性叠加断裂成 出。钾长石化是最发的近矿围为。采用离子探针(SHRIMP)对矿体边部的钾长石化蚀变岩锆石U-Pb定年结果表明:矿化钾长石化蚀变岩的年龄为132±2Ma。由于钾长石化夺本身被金矿化,因此金矿化年龄小于或接近于132±2Ma,为燕山晚期成矿。  相似文献   

18.
内蒙古长山壕金矿区花岗岩同位素年代学研究及地质意义   总被引:3,自引:1,他引:2  
肖伟  聂凤军  刘翼飞  刘研 《岩石学报》2012,28(2):535-543
长山壕金矿床是近年来在内蒙古中西段找到的一特大型金矿床。尽管金矿化在中元古界白云鄂博群变质沉积岩内呈层状、似层状和透镜状产出,但是与各类花岗岩类侵入岩具有密切空间分布关系。本次研究采用LA-ICP-MS方法分别对有关花岗岩类侵入岩进行了系统年代学研究,花岗斑岩和二长花岗斑岩样品的锆石U-Pb年龄值分别为290.9±2.8Ma (MSWD=1.4)和287.5±1.9Ma (MSWD=2.4);2件黑云母花岗岩样品的年龄值分别为267.9±1.2Ma (MSWD=0.95)和274.0±2.3Ma (MSWD=1.4)。根据上述同位素年龄数据,同时结合金矿区野外地质调查和岩(矿)相学证据,可以认为,长山壕金矿区花岗斑岩和二长花岗斑岩及相关金矿床的形成时间为早二叠世早期,并且遭受到早二叠世晚期-中二叠世早期构造-岩浆活动的叠加改造,矿区切穿含金矿脉黑云母花岗岩体的存在就是很好的例证。强烈的中酸性岩浆作用为金矿床的形成提供了动力、热力和物质来源,初步研究结果表明,长山壕金矿床是海西期构造-岩浆作用及相关流体活动的产物,属于与侵入岩有关的中温热液脉型金矿床。  相似文献   

19.
The Tirek gold deposit hosted in the Archean shield is one of the richest sources of mined gold for Algeria. The deposit is controlled by the East Ouzzal shear zone (EOSZ), a transcurrent N–S lithospheric fault. The EOSZ is a late Pan-African dextral-ductile shear zone separating two contrasting Precambrian domains: the Archean In Ouzzal block to the west (Orthogenesis with subordinate metasediments reworked and granulitized during the ca. 2 Ga Eburnean event) and a middle Proterozoic block to the east involved in the ca. 600 Ma Pan-African event. The auriferous quartz veins are mainly oriented in two directions, N–S veins hosted in mylonitic rocks and NE–SW veins hosted in gabbroic or gneissic bands. The NE–SW veins contain the richest ore. Gold ore is found in a system of veins and lenticular quartz veinlets arranged in anastomosing networks. The hydrothermal alteration associated with these veins is characteristically a carbonate-sericite-albite-pyrite assemblage. Gold is the main metal of economic importance; it is disseminated in the quartz as grains or fibers along microcracks and as microscopic grains in the host rocks. Microthermometric results and Raman laser data from fluid inclusions demonstrate that the ore-forming fluids contained H2O-CO2±CH4 and were low salinity. Homogenization temperatures are commonly 250–310 °C. In the Tirek deposit, the role of the shear zone that hosts the mineralization was to drain the hydrothermal fluid. Interactions between the fluid and the mafic host rocks and CO2 also contributed to the formation of the hydrothermal gold deposit at Tirek.  相似文献   

20.
赣西北大雾塘钨矿区地质特征及Re-Os同位素年代学研究   总被引:2,自引:1,他引:1  
通过对大湖塘钨矿田的大雾塘钨矿区辉钼矿Re-Os同位素年代学的研究,测得辉钼矿的w(Re)为0.3368×10~(-6)~8.256×10~(-6),获得的5个模式年龄比较一致,介于(136.6±2.2)Ma~(138.4±2.4)Ma,加权平均年龄为(137.7±2.7)Ma(MSWD=0.07)。将5个模式年龄进行等时线年龄计算,获得一条相关性较好的~(187)Re-~(187)Os等时线,计算得到辉钼矿Re-Os等时线年龄为(137.9±2.0)Ma(MSWD=0.20),与加权平均年龄一致,可代表辉钼矿的形成年龄。结合石门寺和狮尾洞矿区典型矿床地质、地球化学特征和成岩作用时空关系,认为大雾塘矿床的形成是大湖塘钨矿田的第二期次(140 Ma)大规模成矿作用的产物,2期成矿作用可能是大湖塘钨矿田巨量成矿元素堆积的重要原因之一。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号