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1.
巴布亚新几内亚地质构造格架复杂,包括地台、碰撞造山带、外来地体、俯冲带、岛弧和海底扩张中心。巴布亚新几内亚铜金矿床类型主要为斑岩型铜金矿床、浅成低温热液型金银矿床和夕卡岩型铜金矿床（三者之间具有密切的时间、空间和成因关系）,其次为海底块状硫化物矿床。铜金矿床分布比较集中,主要产出于碰撞造山带和岛弧上,其次产出于现代海底扩张中心。铜金矿床大多规模巨大或较大,埋藏较浅,易于勘探和适合露天开采。与铜金矿床有关的岩浆岩大多为钙碱性火山岩和浅成侵入岩,少数与富钾碱性火山岩（橄榄玄粗岩）或侵入岩伴生。铜金矿床蚀变带发育且分带性明显,大多与斑岩体系和／或火山机构有关。虽然许多铜金矿床的矿物成分比较复杂,但是其矿石较易处理和利用。 相似文献
2.
智利科皮亚波GV地区侵入岩地球化学及年代学研究 总被引：3，自引：2，他引：1
智利北中部科皮亚波GV地区位于中生代铁氧化物铜金(IOCG)矿床与斑岩铜矿过渡带。侵入岩体主要为辉长闪长岩、闪长岩、闪长斑岩、黑云母花岗岩、斑状花岗岩和二长岩。岩石地球化学特征说明该侵入岩体属于钙碱性、I型或磁铁矿系列,来源于深部上地幔。推测这些岩浆岩岩石组合形成于洋壳俯冲带,局部扩张与挤压转换导致弧后盆地萎缩封闭并快速抬升。岩浆侵入具有多期次活动,形成了多期次热液活动中心,并发育面型与脉带型蚀变矿化分带,地表具有寻找大型IOCG矿床前景。地表泥化-绿泥石-多孔状硅化网脉和含金银多金属铁锰碳酸盐化网脉发育,含金银多金属网脉状-带状和面型蚀变区揭示地表有浅成低温热液型金银多金属矿床;深部具有寻找隐伏斑岩型铜金矿床前景。今后需在该区加强蚀变矿化分带规律研究,进行深部找矿预测。 相似文献
3.
青藏高原两个斑岩-浅成低温热液矿床成矿亚系列及其"缺位找矿"之实践 总被引：8，自引：8，他引：8
斑岩_浅成低温热液型铜金矿床是西藏最新发现的组合矿床类型,其具有巨大的找矿潜力。笔者在西藏多龙矿集区铁格隆南铜金矿床、雄村矿集区主要矿体系统地质编录、综合研究的基础上,对其矿床地质背景、矿体形态产状、矿物组合、蚀变特征、成岩成矿年龄等进行了系统的总结,在前人研究的基础上,提出班怒成矿带与早白垩世岛弧型中_酸性火山岩_浅成岩组合有关的铜、金、银、铅锌矿床成矿亚系列,以及冈底斯成矿带与早侏罗世—晚侏罗世岛弧型中_酸性火山岩_浅成岩组合有关的铜、金、银、铅锌矿床成矿亚系列,是西藏最重要的寻找斑岩型_浅成低温热液型铜金矿的矿床成矿系列。依据"缺位找矿"理论,预测多龙矿集区尕尔勤、地堡那木岗、铁格隆山是浅成低温热液型铜金矿床的进一步勘查评价区,色那、拿顿角砾岩筒是寻找独立高硫化型浅成低温热液金矿床的重要靶区。铁格隆南浅成低温热液矿体叠加在斑岩型矿体之上,高硫化型浅成低温热液矿床浅部发育多孔状硅帽和明矾石_地开石_高岭石蚀变组合,金属矿物以硫砷铜矿_铜蓝_蓝辉铜矿_黝铜矿_黄铜矿_斑铜矿_黄铁矿等铜硫二元体系矿物组合为主,其中黄铁矿_黄铜矿_斑铜矿形成较早,矿床规模可突破1200万吨。雄村铜金矿集区发育低硫化型浅成低温热液多金属金矿体,矿体呈脉状,或在火山机构边缘构造中独立产出,或叠加于斑岩型铜金矿体之上产出,以绢云母化、叶蜡石化、伊利石化发育,闪锌矿、黝铜矿、磁黄铁矿_黄铁矿为主要金属矿物组合为特征,洞嘎、普钦木_哑达是低硫化型浅成低温热液矿床的勘查评价区,深部有找到斑岩型铜金矿的可能。上述2套矿床成矿系列亚系列都与燕山期斑岩铜金矿床的流体演化有关,具有特殊的蚀变矿物、金属矿物组合,寻找独立的浅成低温热液型金矿是下一步需要重视的找矿方向。 相似文献
4.
浅成低温热液型金矿床研究最新进展 总被引：23，自引：0，他引：23
浅成低温热液型金矿床是目前世界上最为重要的金矿床类型之一 ,也是当前国际矿床学界研究的热点之一。近年来对该类型矿床的深入研究 ,包括对该类矿床的进一步分类、流体形成演化、成矿时代、与碱性岩之间的关系 ,以及与斑岩型及其他类型矿床之间的内在联系等方面均取得了重要进展。研究表明 ,高硫化型与低硫化型金矿床不仅在矿物组合上具有显著差别 ,而且在形成的构造背景、成矿机理等方面也明显不同。高硫化型矿床主要形成于挤压应力场环境和流体混合导致成矿物质沉淀 ,而低硫化型矿床主要产于张性或中性环境下由于流体的沸腾使得矿体形成。浅成低温热液型金矿床的形成时间受其所处大地构造环境演化的控制。与浅成低温热液型金矿床有关的碱性岩通常具有相似的地球化学特征 ,即碱性岩具有异常高的氧逸度和富含挥发份。由于发现大量的浅成低温热液型金矿床与斑岩型矿床之间密切伴生 ,它们之间的内在关系正在引起越来越多矿床学家的重视 ,对其形成机理的研究还有待于进一步深入 相似文献
5.
碱性岩相关铜-金(钼)矿床的研究进展 总被引：1，自引：0，他引：1
由于超过20%的大型-超大型铜-金(钼)矿床与碱性岩浆有关,因此,该类矿床引起矿床学家的广泛关注。碱性岩有关的铜-金矿床的成矿岩体、物化条件及围岩种类各具特色,成矿成因类型多样,主要的成因类型为斑岩型铜-金(钼)、浅成低温热液脉型金-铜(钼)。总体上,该类矿床的矿化和蚀变具有一定的特征:该类矿床多产出在伸展环境下、均富碲化物矿化、有大量的钾质交代作用、含有氟矿物质和钒云母等,成矿蚀变亦有一定的规律。长英质岩石中经常发生钾长石蚀变,而绢云母、碳酸盐和钾长石的混合蚀变常出现在中基性侵入岩中,水热合成石英和酸性蚀变十分罕见。这种特征矿化可能与碱性岩浆流体演化有关,这种流体富含CO_2,且在高氧逸度、低硫逸度条件下释放。在伸展背景下的碱性-钙碱性省寻找此类矿床具有巨大的勘查潜力,尤其在碱性岩体中心及其外围可能形成勘探的靶区。在中国与碱性岩有关的金矿床亦有广阔的找矿前景,在借鉴国外寻找此类矿床经验的同时,仍需加强对与矿化作用有关的岩浆体活动的研究。 相似文献
6.
岩浆热液型银矿床主要指与岩浆热液作用相关的独立银矿床和共生银矿床(Ag平均品位一般大于100g/t),它是银最重要的来源。本文对全球80多个典型的大型-超大型岩浆热液型银矿床进行了梳理和总结,将其主要分为浅成低温热液型(低硫型、中硫型和高硫型)、矽卡岩型、斑岩型和五元素型四种类型,其中浅成低温热液型占主导,斑岩型和矽卡型数量较少。全球大型-超大型的岩浆热液型银矿床主要分布在东太平洋俯冲带和中亚造山带东段,这些银矿床均位于陆壳基底之上。按照发育地区不同可分为六大银成矿省,即中国兴蒙银成矿省、美国西部盆岭银成矿省、墨西哥西北银成矿省、秘鲁中部银多金属成矿省、玻利维亚银锡成矿省和俄罗斯远东银锡成矿省。成矿时代主要集中在中、新生代。这些银成矿省与大规模酸性-中酸性岩浆活动密切相关,包括发育大量酸性熔结凝灰岩的长英质大火成岩省,或者富锡流纹岩、黄玉流纹岩和石英斑岩等高演化岩浆岩。这些大规模岩浆热液银成矿作用通常与区域大地构造背景转换相关,比如从挤压到伸展或者伸展到挤压。相对富银的含水大陆下地壳源区、大规模高分异的岩浆作用、银对熔体中共存硫化物和磁铁矿相对弱的相容性、高盐度的流体、成矿流体集中运移的通道和高效的沉淀机制是银大规模成矿的有利控制因素。银矿床的研究工作相对于铜、金矿床远远落后,银成矿省和酸性大火成岩省的内在联系、控制斑岩钼-银/锡-银两种银成矿系统的机制、岩浆演化对银成矿的控制、银矿潜力区的勘查找矿等关键问题仍亟待解决。 相似文献
7.
西藏具有形成巨型斑岩铜成矿系统的地质背景。浅成低温热液型金矿常发育于斑岩铜成矿系统上部,极具经济价值,但由于形成深度较浅,易于剥蚀,目前西藏地区尚未发现独立的浅成低温热液型金矿床。多龙超大型铜金矿集区位于西藏班公湖-怒江成矿带西段,产出有大型-超大型斑岩-浅成低温热液型铜金矿床,而是否存在独立的浅成低温热液型金矿,既是重大科学问题,也是勘查的重点方向。文章运用超景深高分辨数码显微镜、扫描电镜及电子探针等手段,系统研究了多龙矿集区尕尔勤矿区内的残坡积物和外围水系沉积物中746颗砂金的大小、形貌、核部元素及不透明矿物包体特征,发现尕尔勤矿区内广泛分布的砂金不是表生环境下生物化学或化学成因金,而是尕尔勤产出的金矿(化)体剥蚀的产物。砂金普遍含有较高的w(Bi)、极低的w(Cu),部分含有高的w(Hg)、w(Te);砂金w(Ag)变化较大（0.05%～40.21%）;金成色变化范围较大（588～999）;砂金富含Bi-Pb-Te-S系列矿物包体等,显示尕尔勤矿区可能存在一个遭受过剥蚀的浅成低温热液金矿床。 相似文献
8.
Cripple Creek and other alkaline-related gold deposits in the southern Rocky Mountains, USA: influence of regional tectonics 总被引：1，自引：0，他引：1
Alkaline-related epithermal vein, breccia, disseminated, skarn, and porphyry gold deposits form a belt in the southern Rocky Mountains along the eastern edge of the North American Cordillera. Alkaline igneous rocks and associated hydrothermal deposits formed at two times. The first was during the Laramide orogeny (about 70-40 Ma), with deposits restricted spatially to the Colorado mineral belt (CMB). Other alkaline igneous rocks and associated gold deposits formed later, during the transition from a compressional to an extensional regime (about 35-27 Ma). These younger rocks and associated deposits are more widespread, following the Rocky Mountain front southward, from Cripple Creek in Colorado through New Mexico. All of these deposits are on the eastern margin of the Cordillera, with voluminous calc-alkaline rocks to the west. The largest deposits in the belt include Cripple Creek and those in the CMB. The most important factor in the formation of all of the gold deposits was the near-surface emplacement of relatively oxidized volatile-rich alkaline magmas. Strontium and lead isotope compositions suggest that the source of the magmas was subduction-modified subcontinental lithosphere. However, Cripple Creek alkaline rocks and older Laramide alkaline rocks in the CMB that were emplaced through hydrously altered LREE-enriched rocks of the Colorado (Yavapai) province have 208Pb/204Pb ratios that suggest these magmas assimilated and mixed with significant amounts of lower crust. The anomalously hot, thick, and light crust beneath Colorado may have been a catalyst for large-scale transfer of volatiles and crustal melting. Increased dissolved H2O (and CO2, F, Cl) of these magmas may have resulted in more productive gold deposits due to more efficient magmatic-hydrothermal systems. High volatile contents may also have promoted Te and V enrichment, explaining the presence of fluorite, roscoelite (vanadium-rich mica) and tellurides in the CMB deposits and Cripple Creek as opposed to deposits to the south. Deep-seated structures of regional extent that formed during the Proterozoic allowed the magmas to rise to shallow crustal levels. Proterozoic sites of intrusions at 1.65, 1.4, and 1.1 Ga were also important precursors to alkaline-related gold deposits. Many of the larger gold deposits are located at sites of Proterozoic intrusions, and are localized at the intersection of northeast-trending ductile shear zones formed during Mesoproterozoic deformation, and an important north-trending fault formed during 1.1 Ga rifting. 相似文献
9.
金是南美洲仅次于铜的优势矿种,据美国地质调查局统计,2016年秘鲁金矿储量2800 t,巴西金矿储量2400 t,智利仅公布到2014年金矿储量3900 t。通过对南美安第斯成矿带和南美地台金矿地质背景分析,根据对31个大型-超大型金矿的综合研究,剖析斑岩型、浅成低温热液型、IOCG型、造山型等不同类型金矿床的时空分布、地质特征,梳理重要成矿区特征,摸清区域构造岩浆-成矿作用演化的关系,为以后在南美洲金矿的勘查开发提供科学依据。在安第斯成矿带,金成矿作用与太平洋板块向南美大陆板块的俯冲密切相关,大型-超大型金矿类型主要是以浅成低温热液型,以及与铜共生的斑岩型、IOCG型矿床为主,大规模金成矿作用集中在新生代,形成了众多世界著名的金矿床。南美地台成矿带位于亚马孙陆块边缘,受古元古代(2.5~1.8 Ga)Trans-Amazonian旋回影响,经历了反复俯冲造山运动,大型-超大型金矿以造山带型金矿为主,主要成矿期在太古宙—新元古代。南美的金资源相当丰富,未来具有巨大的勘查开发潜力。 相似文献
10.
埃达克岩与Cu-Au成矿作用：有待深入研究的岩浆成矿关系 总被引：29，自引：19，他引：29
研究表明，环太平洋地区新生代斑岩铜矿和浅成热液金矿与同期的埃达克质岩浆活动存在密切的时空与成因联系。埃达克岩是许多世界级的斑岩铜矿的容矿岩，也是许多浅成热液矿化系统的成矿母岩浆。根据目前的研究，二者成因联系可能在于埃达克质岩浆的富流体、高氧逸度和基性源岩等固有属性，有利于Cu、Au等深源金属元素的萃取与富集成矿一因此，这可能是一种潜在的岩浆成矿专属性关系，但对产生这种关系的原因与机制仍然不十分清楚。这有待于今后深入开展成矿与无矿的埃达克岩、成矿的埃达克岩与非埃达克岩、无矿的埃达克岩与非埃达克岩等方面的对比研究，以揭示这种成矿专属性的本质。 相似文献
11.
文章首次对蒙甘新相邻(北山)地区各类金、铜和铜—镍矿床(点)地质特征、成因类型和空间分布特点进行了系统总结，论证了金、铜和铜—镍成矿作用与古生代岩浆活动的关系，对区域地壳演化过程中金、铜和铜—镍成矿的动力学机制进行了深入讨论。研究结果表明，该区的金矿床(点)大体可划分为变质岩型、火山岩型、斑岩型和深成侵入岩型；铜矿床(点)有斑岩型、夕卡岩型和铜—镍硫化物型。金和铜矿床(点)大都沿古板块汇聚带分布，与海西期火成岩具密切的时空分布关系，它们是古板块对接碰撞期和碰撞期后大规模构造—岩浆活动的产物。 相似文献
12.
黑龙江省乌拉嘎金矿赋矿花岗闪长斑岩锆石 U-Pb年龄、岩石成因及其地质意义 总被引：5，自引：3，他引：2
黑龙江省是我国著名金矿产区之一,发育多个浅成低温热液型金矿,它们与中生代陆相火山-次火山岩有密切的关系,但对这些陆相火山-次火山岩的成因缺乏系统研究,制约了本区金矿的成因认识和矿床勘查。本次研究采用先进的LA-ICP-MS锆石定年法、地球化学Sr-Nd-Pb同位素示踪等方法,对与乌拉嘎浅成低温热液金矿存在密切成因联系的次火山岩(花岗闪长斑岩)进行深入研究。LA-ICP-MS锆石定年法获得乌拉嘎矿区葡萄沟岩体及其南部含矿岩枝的成岩年龄分别为108.2±1.2Ma和106±1.1Ma,与区内宁远村组火山岩成岩时间基本相近,推断金矿成矿时代为早白垩世晚期,与东安金矿和高松山金矿为同期。岩石地球化学确定该岩体为高钾钙碱性(σ=1.83~2.18)偏铝质I型花岗岩特征,结合微量元素和Sr-Nd-Pb研究显示其具有活动陆缘弧岩浆岩特点,进一步得出岩浆源区和成矿物质具有来源于新元古代形成的镁铁质下地壳的部分熔融的属性。早白垩世时,中国东部处于伸展应力体制下,尤其黑龙江构造活动强烈,起源于新生下地壳重融的岩浆活动频繁,结合已有的浅成低温热液金矿床资料显示,推断区内具有巨大的成矿潜力。 相似文献
13.
西藏谢通门县雄村铜金矿区及其外围的找矿前景地球化学评价 总被引：3，自引：0，他引：3
雄村铜金矿床的发现是近年来西藏冈底斯成矿带找矿的重大突破之一。在评价找矿前景、圈定成矿有利地段和钻探工程部署的过程中,勘查地球化学起了重要的作用。通过对雄村铜金矿区及其外围的地球化学测量结果的研究,综合实际地质情况,我们得出以下两点认识：（1）雄村矿区及其外围是一个具有以斑岩型铜金矿化为主、兼有热液型金（或铜）矿化和矽... 相似文献
14.
Discovery and exploration of the Gosowong epithermal gold deposit, Halmahera, Indonesia 总被引：1，自引：0，他引：1
J. C. Carlile G. R. Davey I. Kadir R. P. Langmead W. J. Rafferty 《Journal of Geochemical Exploration》1998,60(3):207-227
The Gosowong epithermal gold deposit, on the island of Halmahera in eastern Indonesia, is located in an area of primary tropical rain forest with no previous history of gold mining or record of gold mineralisation. The deposit occurs in a newly recognised mineral district which contains a number of epithermal vein systems and at least two centres of low-grade porphyry style Cu–Au mineralisation. Several zones of argillic and advanced argillic alteration have been noted which may be related to additional centres of mineralisation. Gosowong is classified as a low-sulphidation epithermal quartz vein. Bonanza-grade gold–silver mineralisation is developed in shoots over a 400-m strike section of the vein system. Three types of veining are recognized; quartz–adularia veins and breccias; quartz–chlorite–illite veins and breccias; and crystalline or chalcedonic quartz vein stockworks. The area was targetted using a simple geological concept and the deposit was discovered and tested using basic exploration techniques commonly applied in the rugged tropical terrains of Indonesia. Sequential exploration methods comprised reconnaissance drainage sampling of stream sediment, BLEG and float media, ridge and spur soil sampling, prospect scale grid soil sampling, hand trenching and diamond drilling. Lapse time from identification of the initial reconnaissance anomaly to an inferred resource estimate of almost 1 million ounces of gold was less than 3.5 years. This case history illustrates that very detailed exploration is necessary to locate high-grade vein-type gold deposits in a tropical environment, but demonstrates that such resources still remain to be discovered in the relatively under-explored Neogene magmatic arcs of Indonesia. 相似文献
15.
16.
This study is an attempt to understand the application of spectral image processing methods to ASTER data for mapping host rock associated with porphyry copper-molybdenum mineralization. The application of remote sensing in identifying variations in surface mineralogy, structural elements, and lithologic contacts can help in identifying such relations. Signatures collected from the Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER) data is used to map the host rock of Zafarqand area. The study area is located in the central segment of the Urumieh–Dokhtar volcanic belt of Iran. The Urumieh-Dokhtar is a potential zone for exploration of new porphyry copper deposits. Band ratio, band math, false colour composites and principal component analysis techniques are used to refine the different lithologic units in the area. These methods showed the discrimination of acidic igneous rock from intermediate igneous rock and the boundary between igneous rocks using the shortwave infrared bands (SWIR) of ASTER at regional scale. Results have proven to be effective and in accordance with the results of field observations, ore microscopy examination and with reference geological map. In conclusion, the image processing methods used can provide cost-effective information to discover possible locations of porphyry copper and epithermal gold mineralization prior to detailed and costly ground investigations. The extraction of spectral information from ASTER data can produce comprehensive and accurate information for copper and gold resource investigations around the world, including those yet to be discovered. 相似文献
17.
《International Geology Review》2012,54(5):608-632
The margin of NE China, a part of the West Pacific metallogenic belt, contains innumerable low-sulphidation mineral deposits. Gold deposits in this region can be classified into three distinct types based on geology and ore mineral paragenesis: (1) low-sulphidation epithermal silver–gold deposits, (2) low-sulphidation tellurium–gold deposits, and (3) low-sulphidation epithermal tellurium–gold deposits. Ores formed during the late Early Cretaceous and the early Late Cretaceous reflect three distinct metallogenic periods: the Fuxin Stage at 115.98 ± 0.89 Ma, the Quantou Stage at 107.2 ± 0.6 Ma or <103 Ma, and the Qingshankou or Yaojiajie Stage at < 97 Ma and 88.2 ± 1.4 Ma. The Fuxin Stage is dominated by trachyandesitic magmatism, with magmas emplaced at hypabyssal depths. In comparison, the Quantou Stage is characterized by high-K calc-alkaline, calc-alkaline, and sodic andesitic, dacitic, and rhyolitic magmatism of three different suites. The first of these is a high-K calc-alkaline andesitic magmatic suite that was accompanied by the emplacement of a calc-alkaline sodic dacite during the formation of the Ciweigou and Wufeng ore deposits. The second suite is dominated by calc-alkaline sodic rhyolite and high-K calc-alkaline sodic dacite magmatism associated with the formation of the Sipingshan ore deposit. The third suite is typified by high-K calc-alkaline andesitic magmatism associated with the emplacement of calc-alkaline hypabyssal granitoid complexes accompanying the formation of the Dong'an and Tuanjiegou ore deposits. The Qingshankou or Yaojia Stage is characterized by calc-alkaline sodic dacite magmatism associated with the formation of the Wuxing ore deposit. Metallogenesis during the Fuxin Stage characterized by trachytic magmatism is closely related to the formation of a deep-seated fault within a magmatic arc or the back-arc region of an immature continental margin and is associated with the Early Cretaceous subduction of the Pacific plate beneath Eurasia. Ore deposits that formed during the Fuxin Stage were generally related to magmato-hydrothermal fluids associated with mantle-derived magmas. In contrast, metallogenesis during the Quantou and Qingshankou or Yaojiajie stages was closely related to the formation of a mature high-K calc-alkaline magmatic arc within a continental margin setting again associated with the westward subduction of the Pacific plate. This metallogenic event was a product of magmato-hydrothermal systems derived from crust–mantle interaction and mixing of magmas derived from partial melting of different sections of the continental crust. 相似文献
18.
《International Geology Review》2012,54(3):287-310
The continental margin of Northeast China, an important part of the continental margin-related West Pacific metallogenic belt, hosts numerous types of gold-dominated mineral deposits. Based on ore deposit geology and isotopic dating, we have classified hydrothermal gold–copper ore deposits in this region into four distinct types: (1) gold-rich porphyry copper deposits, (2) gold-rich porphyry-like copper deposits, (3) medium-sulphidation epithermal copper–gold deposits, and (4) high-sulphidation epithermal gold deposits. These ore deposits formed during four distinct metallogenic stages or periods, at 123.6 ± 2.5 Ma, 110–104 Ma, 104–102 Ma, and 95.0 ± 2 Ma, corresponding to periods of Cretaceous intermediate–acid volcanism and late-stage emplacement of hypabyssal magmas along the northern margin of the North China platform. The earliest stage of mineralization (123.6 ± 2.5 Ma) corresponds to the formation of medium-sulphidation epithermal copper – gold deposits and was associated with a continental margin magmatic arc system linked to subduction of the Pacific Plate beneath the Eurasia. This metallogenesis is closely related to high-K calc-alkaline intermediate–acid granite and pyroxene – diorite porphyry magmatism. The second and third stages of mineralization in the study area (110–104 Ma and 104–102 Ma, respectively) correspond to the formation of gold-rich porphyry copper, porphyry-like copper, and high-sulphidation gold deposits, with metallogenesis closely related to sodic or adakitic magmatism. These magmas formed in a continental margin magmatic arc system related to oblique subduction of the Pacific Plate beneath the Eurasia, as well as mixing of crust-derived remelted granitic and mantle-derived adakitic magmas. During the final stage of mineralization (95.0 ± 2 Ma), metallogenesis was closely related to sodic or adakitic magmatism, with diagenesis and metallogenesis related to the disintegration or destruction of the Pacific Plate, which was subducted beneath the Eurasian Plate during the Mesozoic. 相似文献
19.
西藏冈底斯成矿带浅成低温热液型金锑矿床的发现及其意义--以西藏弄如日金锑矿床为例 总被引：9，自引：3，他引：6
通过化探、槽探和平硐等手段,对位于冈底斯成矿带东段的弄如日金矿床进行了评价和研究,在矿区发现金矿化带4条,圈出金矿体5个,控制2．3g／t品位以上的金资源量（333＋3341）为2．97t,确定该矿床属典型的浅成中低温热液型金矿床。矿区的金矿体赋存于破碎蚀变角岩和蚀变二长花岗斑岩中,受南北向正断裂系统的控制,矿化以金为主,伴有辉锑矿、雄黄、黄铁矿等矿物,可分为浅成低温热液和表生氧化2个成矿期,金可能以独立的自然金状态存在于脉石矿物的粒问或裂隙中。弄如日金矿床形成于伸展构造背景,在空间上居斑岩铜矿床外围,成矿时代为中新世一上新世,与冈底斯斑岩型铜钼矿床及其外围的矽卡岩型铅锌矿床的成矿时代基本一致,说明三者受统一的成矿作用制约,属斑岩岩浆一热液成矿系统中的浅成低温热液型金锑矿床。 相似文献
20.
东南亚巽他群岛是新生代埃达克岩、类埃达克岩极其发育的地区。这些中酸性岩浆岩广泛见于几内亚岛上的中央山脉、巴布亚新几内亚的欧文-斯坦利推覆带、俾斯麦岛弧、布干维尔岛-所罗门岛弧、印度尼西亚苏拉威西、加里曼丹中部、班达岛弧,零星见于苏门答腊、爪哇等地。根据微量元素特征及REE曲线类型的特点,本区埃达克岩可以明显地划分为2种类型：第一种埃达克岩类型属于拉斑/钙-碱性系列,具有大洋岛弧的REE曲线特征（相当于O型埃达克岩）;第二种埃达克岩属于高钾钙-碱性系列,归于大陆埃达克岩（相当于C型埃达克岩）,形成于弧-陆碰撞带或碰撞后造山带。埃达克岩与浅成热液金属矿床和斑岩矿床的成矿作用有密切的关系,是世界级浅成热液和斑岩铜-金矿的容矿岩石。 相似文献