西秦岭甘肃段特大型金矿床的地质地球化学特征及其成岩成矿年龄

Geological,Geochemical Characteristics and Diagenetic Age of the Super-large Gold Deposits in Western Qinling,Gansu Province

西秦岭是中国具有大型、特大型金矿成矿条件的成矿带,通过对西秦岭甘肃段4个特大型金矿之间及其卡林型金矿、造山型金矿的地质、地球化学特征对比研究表明:这4个特大型金矿均具有多期多次成矿的特点,且具有由卡林型金矿向造山型金矿过渡的特征,成矿作用发生在碰撞造山阶段的挤压向伸展转换期,代表了一种新的成矿类型,建议定义为"卡林-造山复合型",特大型金矿成矿时间为127~216 Ma,成矿背景及成矿时间具有偏在性。

The West Qinling metallogenic belt has good condition for forming large and super large gold deposits in China. In this paper, the geological and geochemical characteristics of four super large deposits in West Qinling, Gansu Province have been analyzed, and they are compared with the ones of Karlin type and orogenic gold deposits. The results show that these four super large gold deposits have many characteristics of multi stage mineralization, and they have the transition characteristics of changing from Karlin type gold deposit to orogenic gold deposit.The gold mineralization was occurred in the collision orogenic stage, which has been defined as “Carlin orogenic compound type”.The metallogenic age of these super large gold deposits is 127~216 Ma, the metallogenic background and time show the metallogenic preferentiality.