相山铀矿田巴泉隐爆角砾岩(筒)地质特征与铀成矿

The Geological Features and Uranium Mineralization of Baquan Cryptoexplosion Breccia in Xiangshan Orefield

巴泉铀矿床位于相山矿田的北部边缘,是典型的隐爆角砾岩(筒)型铀矿床。隐爆角砾岩(筒)是由与相山火山机构有密切联系的燕山晚期侵入于震旦系变质岩中的潜花岗斑岩岩枝发生隐爆作用而生成。矿床是多阶段岩浆活动、多次隐爆作用和多期铀成矿作用互为响应、连续发展地质过程的产物,是集岩浆岩体-角砾岩体-铀矿体为一体的综合地质单元。燕山晚期潜花岗斑岩浆和英安玢岩浆的侵入、隐爆作用形成的角砾岩(筒),以及断裂构造的频繁运动,对铀成矿乃至矿床的形态和规模起到重要的控制作用。隐爆角砾岩(筒)的形成具有脉动性、隐爆性,显示隐爆角砾岩岩性的复杂多变,矿化蚀变种类、组合和强弱变化具有规律性。铀矿体(化)主要赋存于隐爆角砾岩和震碎角砾岩中,矿化显现出中富边贫、上强下弱的特征。

Located in the north of Xiangshan orefield, Baquan uranium deposit is a typical cryptoexplosion breccia related deposit. The cryptoexplosion breccia pipe was closely related to the granite porphyry rock sticks which penetrated into the Sinian metamorphic strata in Late Yanshanian. It＇s a comprehensive geological body of igneous rock, breccia bodies and ores which is the product of a continuous geological process affected by multi-stage magmatic activity, and hidden explosion. The intrusion of granite porphy- ry and dacite porphyry in Late Yanshanian, and the formation of crypto explosion breccia and the faults structure are very important to the uranium deposits. The pulesating and hidden cryptoexplosion resultet in the variety of rocks and mineralization alteration. Uranium ore body mainly occurred in cryptoexplosion and shattered breccia and the mineralization is rich in the centre and upper but poor in the edge and bottom of the pipe.