中文摘要:为了解四川西部夏塞银多金属矿区黑云母二长花岗岩形成和矿化发生的时 代及成矿物质来源,测定了该矿区绒依措和若洛隆花岗岩的Rb_Sr年龄和钾长石、黑云母及 主要银矿化阶段石英的 40Ar/39Ar年龄及矿石的硫、铅同位素组成 。花岗岩的结晶年龄约为93 Ma,银矿化年龄约为75 Ma。矿石硫可能源于花岗岩,但不能 排除源于弱沉积围岩的可能性;矿石、花岗岩和弱变质沉积围岩的铅同位素组成相 似,铅主要源于上地壳,少量源于下地壳。
Abstract:In this paper, the authors obtained Rb_Sr isochron ages of the Rongyicuo and Ruo
luolong biotite monzonite batholiths and 40Ar/39Ar ages of K _feldspar and biotite in the granite of the ore district, dated quartz from the main silver mineralization and determined sulfur and lead isotope compositions o f the ore minerals so as to understand timing and origin of ore materials in the Xiasai silver polymetallic deposit of western Sichuan. The crystallization tim ing of the Rongyicuo and Ruoluorong granite batholiths are approximately 93 Ma. The timing of silver mineralization is about 75 Ma. Sulfur of the ore is likel y from granite, but the possibility from the lower metamorphic sediments cannot be excluded. Ores, granite and lower metamorphic sediments are similar to each other in lead isotope composition, suggesting that lead was mostly derived from the upper crust and subordinately from the lower crust. It is considered that t he silver polymetallic ores were deposited in the NW_trending faults in the oute r contact zone of the granite batholith through the mixture of hydrothermal flui ds fractioned by crystallizing granite magma and hydrothermal fluids circulating in the country rocks as a result of elevated geothermal grade during the intrus ion of the granite. The silver_polymetallic mineralization has close genetic re lationship with the granitic magmatism.
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基金项目:国家重点基础研究项目(G1999043200)
引用文本:
应汉龙, 王登红, 付小方.2006.四川巴塘夏塞花岗岩和银多金属矿床年龄及ち颉⑶ν位素组成[J].矿床地质,25(2):135~146应汉龙, 王登红, 付小方.2006.Timing and lead and sulfur isotope composition of Xiasai granite ?nd silver po lymetallic deposit in Batang, Sichuan Province[J].Mineral Deposits25(2):135~146
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