西藏班戈县东嘎花岗岩体特征及锡找矿前景分析

东嘎花岗岩体位于冈底斯一念青唐古拉板片北缘、班公错一怒江结合带中段班戈一崩错板片。岩体时代为燕山晚期，属印度一欧亚板块碰撞造山构造环境。岩石属富钠、硅铝过饱和类型，该岩体位于斑戈一嘉黎一波密一察隅锡成矿远景带内，岩浆分异程度高，具有S型花岗岩体的典型特征，与滇西、川西含锡花岗岩体特征相似，成矿条件有利。区域化探资料显示锡异常明显，异常为Sn、Rb、Y、u、Nb、Ag、w、Th、Pb等多元素组合。sn元素的强度高、规模大。据区域地质、岩石化学及地球化学特征及区域成矿资料，东嘎花岗岩体具有良好的锡成矿前景。

Donga Granite Body Characteristics and Tin Prospect Analysis in Baingoin County,Tibet

The Donga granite body is situated in the Baingoin--Bangkog Co plate, middle sector of Banggong Co--Nujiang suture belt, north margin of Gangdise-- Nyainqen Tanglha plate. The age of granite body belongs to late Yanshanian, within the subduction of Indi- an plate under Eurasian plate orogenic tectonic setting. Rocks belong to sodium rich, silicon and aluminum oversaturated type. The granite body is located in the Baingoin--Lhari--Bomi--Zayu tin metallogenic prospect belt, high degree of rock differentiation with S type granite body typical characteristics, similar to western Yunnan and western Sichuan tin-bearing granite body, thus favorable ore- forming condition. Regional geochemical prospecting data have shown obvious tin anomaly, that is Sn, Rb, Y, U, Nb, Ag, W, Th and Pb element association. The element Sn has high intensity, large dimension. Based on regional geological, lithochemical and geochemical characteristics and regional metallogenic data, Donga granite body has good tin ore-forming prospect.