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湘东锡田钨锡多金属矿床是地质大调查期间发现的一个大型矿床。矿体赋存在锡田复式花岗岩中及其与中泥盆统棋梓桥组的接触带上,主要矿床类型为矽卡岩型和破碎带蚀变岩型,其次为云英岩(或云英岩-石英脉)型。该复式花岗岩可划分为主体(中细粒斑状黑云母花岗岩)、补体(细粒含斑黑云母花岗岩)和晚期侵入体(细粒二云母花岗岩)。采用锆石SHRIMPU-Pb法,获得主体花岗岩的形成年龄为230.4±2.3Ma(MSWD=1.6)。本文通过对课题组及前人其它测年资料的对比分析,认为锡田复式花岗岩主体、补体和晚期侵入体分别属于印支期、燕山早期和燕山晚期;成矿作用与燕山早期花岗岩关系密切,是华南燕山早期大规模成岩成矿作用高峰期的产物。
The Xidian tungsten-tin polymetallic deposit in East Hunan is a large deposit discovered during the geological survey. The orebodies occur in the contact zone of the Xitian multi-granite and the Central Guizhou basin in the Zhiziqiao Formation. The main types of deposits are skarn type and crustal alteration rock type, followed by Yunyan (or Yungying Rock - quartz vein) type. The compound granite can be divided into the main body (fine-grained biotite granite), complement (fine-grained biotite granite) and late intrusive (fine-grained micaceous granite). Using zircon SHRIMPU-Pb method, the formation age of the main granite was 230.4 ± 2.3Ma (MSWD = 1.6). Based on the comparative analysis of other dating data of the research group and predecessors, the author thinks that the main body, complement and late intrusion of the tin multi-granite belong to the Indosinian, Early Yanshanian and Late Yanshanian periods respectively; the mineralization is closely related to the early Yanshanian granite, It is the product of the early stage of large-scale granitoids mineralization in South China.