排序方式： 共有53条查询结果，搜索用时 440 毫秒
31.
《China Geology》2022,5(4):662-695
The porphyry copper belt in the Geza island arc in southwestern China is the only Indosinian porphyry copper metallogenic belt that has been discovered and evaluated so far. The Pulang porphyry copper deposit (also referred to as the Pulang deposit) in this area has proven copper reserves of 5.11×106 t. This deposit has been exploited on a large scale using advanced mining methods, exhibiting substantial economic benefit. Based on many research results of previous researchers and the authors’ team, this study proposed the following key insights. (1) The Geza island arc was once regarded as an immature island arc with only andesites and quartz diorite porphyrites occurring. This understanding was overturned in this study. Acidic endmember components such as quartz monzonite porphyries and quartz monzonite porphyries have been identified in the Geza island arc, and the mineralization is mainly related to the magmatism of quartz monzonite porphyries. (2) Complete porphyry orebodies and large vein orebodies have developed in the Pulang deposit. Main orebody KT1 occurs in the transition area between the potassium silicate alteration zone of quartz monzonite porphyries and the sericite-quartz alteration zone. Most of them have developed in the potassium silicate alteration zone. The main orebody occurs as large lenses at the top of the hanging wall of rock bodies, with an engineering-controlled length of 1920 m and thickness of 32.5‒630.29 m (average: 187.07 m). It has a copper grade of 0.21%‒1.56% (average: 0.42%) and proven copper resources of 5.11×106 t, which are associated with 113 t of gold, 1459 t of silver, and 170×103 t of molybdenum. (3) Many studies on diagenetic and metallogenic chronology, isotopes, and fluid inclusions have been carried out for the Pulang deposit, including K-Ar/Ar-Ar dating of monominerals (e.g., potassium feldspars, biotites, and amphiboles), zircon U-Pb dating, and molybdenite Re-Os dating. The results show that the porphyries in the Pulang deposit are composite plutons and can be classified into pre-mineralization quartz diorite porphyrites, quartz monzonite porphyries formed during the mineralization, and post-mineralization granite porphyries, which were formed at 223±3.7 Ma, 218±4 Ma, and 207±3.9 Ma, respectively. The metallogenic age of the Pulang deposit is 213‒216 Ma. (4) The petrogeochemical characteristics show that the Pulang deposit has the characteristics of volcanic arc granites. The calculation results of trace element contents in zircons show that quartz monzonite porphyries and granite porphyries have higher oxygen fugacity. The isotopic tracing results show that the diagenetic and metallogenic materials were derived from mixed crust- and mantle-derived magmas.©2022 China Geology Editorial Office. 相似文献
32.
滇西北普朗斑岩铜矿与成矿有关的花岗岩与全球埃达克岩的对比:大数据研究的初步结果 总被引：1，自引：0，他引：1
云南格咱岛弧是西南三江构造-岩浆岩带中义敦岛弧的重要组成部分,位于义敦岛弧带的南端,是中国西部地区一个重要的铜铅锌多金属成矿带和印支期斑岩铜矿带,其中普朗斑岩型铜矿是印支期斑岩铜矿的典型代表。本文在前人研究基础上,采用大数据分析技术,对普朗斑岩铜矿与成矿有关的花岗岩与全球埃达克岩进行了对比研究,得到506个元素组合,获得交叠率比值127765个。结果表明,普朗斑岩与全球埃达克岩的地球化学数据基本上重叠,具有与全球埃达克岩类似的特征;但Cu、Mo、Pb、Zn成矿元素明显超出全球埃达克岩的分布范围,REE和Ga与主元素的比值虽然在全球埃达克岩范围内,却显示了位于全球埃达克岩某个端元的现象。另外,与斑岩铜矿有关的埃达克岩分布于全球埃达克岩范围的局部,数据部分或大部分逸出了全球埃达克岩分布的范围,具有低Sr/Cu、Ta/Cu、Al/Mo、Mn/Zn、Mn/Cu、Mn/Mo以及Hf、K、Ti、P、Co、Th、Ca/Cu比值的特征,数据点偏离全球埃达克岩范围越远,蚀变与矿化作用越强烈,与铜钼成矿关系越密切。本文地球化学数据挖掘结果可以作为找矿标志来使用,这为普朗铜矿床深部及外围的地质找矿提供了新的科学依据。 相似文献
33.
34.
35.
赋矿的普朗含矿复式斑岩体,具典型斑状特征及铜、钼、铁成矿专属性,由边缘到中心具石英闪长玢岩→石英二长斑岩演化关系,硅化钾化、绢英岩化蚀变与铜矿关系密切,尤以石英二长斑岩蚀变和矿化作用最强烈。硫同位素表明岩体属幔-壳源硫特征,铅同位素显示岩体铅集中分布于造山带演化线附近及下地壳、造山带、岛弧重叠区的特征。 相似文献
36.
37.
滇西北中甸普朗斑岩铜矿床地球化学与成矿机理初探 总被引：25，自引：0，他引：25
普朗斑岩铜矿是一个典型的与洋壳俯冲相关的大型乃至超大型矿床,通过对矿区代表性含矿斑岩与无/弱矿化斑岩的稀土元素特征对比、硫同位素示踪等方面的研究,表明矿石随Cu品位的增高,稀土总量(∑REE)和稀土分馏参数〔(LREE/HREE)、(La/Yb)N及(La/Yb)N、(Gd/Yb)N〕呈连续降低趋势,负铕异常一般显示为逐渐增强的趋势,但在发育有强烈的晚期钾长石脉的情况下,出现反弹减弱特征。硫化物(黄铜矿、黄铁矿和辉钼矿)的δ34SCDT变化范围为-2.23‰～3.75‰,基本呈塔式分布特征,主要为深源岩浆硫。 相似文献
38.
Geochemical Characteristics and Zonation of Primary Halos of Pulang Porphyry Copper Deposit,Northwestern Yunnan Province,Southwestern China 总被引：6，自引：0，他引：6
The Pulang (普朗) porphyry copper deposit, located in the southern segment of the Yidun-Zhongdian (义敦-为中甸) island arc ore-forming belt of the Tethys-Himalaya ore-forming domain, is a recently discovered large copper deposit. Compared with the composition of granodiorite in China, the porphyry rocks in this area are enriched in W, Mo, Cu, Au, As, Sb, F, V, and Na2O (K1≥1.2). Compared with the composition of fresh porphyry rocks in this district, the mineralized rocks are enriched in Cn, Au, Ag, Mo, Pb, Zn, W, As, Sb, and K2O (K≥1.2). Some elements show clear anomalies, such as Zn, Ag, Cu, Au, W, and Mo, and can be regarded as pathfinders for prospecting new ore bodies in depth. It has been inferred from factor analysis that the Pulang porphyry copper deposit may have undergone the multiple stages of alteration and mineralization: (a) Cu-Au mineralization; (b) W-Mo mineralization; and (c) silicification and potassic metasomatism in the whole ore-forming process. A detailed zonation sequence of indicator elements is obtained using the variability index of indicator elements as follows: Zn→Ag→Cu→Au→W→Mo. According to this zonation, an index such as (Ag×Zn) D/(Mo×W) D can be constructed and regarded as a significant criterion for predicting the Cu potential at a particular depth. 相似文献
39.
云南普朗斑岩铜矿床热液蚀变及脉体系统研究 总被引：1，自引：0，他引：1
云南普朗超大型斑岩铜矿床位于西南三江成矿带中段,形成于岛弧构造环境,是印支期甘孜-理塘洋壳向西俯冲于格咱-中甸微陆块之下,并引发大规模岩浆-成矿作用的结果。本文通过对矿区围岩蚀变及脉体系统的调查和大量的镜下薄片鉴定研究,总结首采区与外围的蚀变分带及脉体特征。结果表明,首采区的围岩蚀变从岩体由内向外,依次为钾硅酸盐化带-绢英岩化带-青磐岩化带-角岩化带,泥化和碳酸盐化多叠加于其它蚀变带之上,不形成独立蚀变带,铜矿化主要发育于钾硅酸盐化带中,以浸染状矿化为主,含矿岩体为石英二长斑岩。北部及东部外围的钾硅酸盐化带缺失或微弱,主要发育绢英岩化带-青磐岩化带-角岩化带-碳酸盐化带,铜矿化多发育于绢英岩化带中,以脉状矿化为主,含矿岩体为石英二长斑岩及闪长玢岩。首采区与外围的脉体系统具多期次-多类型特征,在A、B、D三大类型脉中,前二者对成矿的贡献大。矿区蚀变特征总体与"二长岩"模式相符合,并与国内西藏玉龙、驱龙、多龙及多不杂等斑岩型铜矿床相似。 相似文献
40.
云南中旬地区两个斑岩铜矿容矿斑岩的地球化学特征——以雪鸡坪和普朗斑岩铜矿床为例 总被引：13，自引：0，他引：13
位于义敦岛弧南端的中甸岛弧已成为我国又一重要的斑岩铜矿产地，其中雪鸡坪中型斑岩铜矿床产于西斑岩带，普朗超大型斑岩铜矿床产于东斑岩带。详细对比研究了这两个斑岩铜矿床矿床地质，含矿斑岩的岩石化学、地球化学以及年代学等特征，认为：①两者的元素组成非常相似，如稀土配分形式均为轻稀土元素富集型，亏损重稀土元素和Y，富集Sr、K、Rb、Ba、Th等大离子亲石元素，亏损Nb、Ta、Zr、Hf、置等高场强元素，显示了埃达克岩的地球化学特征，表明它们可能是俯冲的甘孜-理塘洋壳部分熔融的产物，并受到地壳物质的混染；②中甸岛弧的结构及时空演化保持了义敦岛弧的共性，发育完整的沟-弧-盆体系，其中东斑岩带属于外弧，而西斑岩带属于内弧，中斑岩带及零星分布的属都蛇绿混杂岩产于弧间盆地。 相似文献