金堆城与沙坪沟小岩体型斑岩钼矿床对比研究

The Comparative Study on Small Intrusion Type Molybdenum Deposits of Shapinggou and Jinduicheng

金堆城和沙坪沟钼矿床为东秦岭—大别钼矿带最典型的2个大(超大)型小岩体型斑岩钼矿床。通过对其基本特征、成矿时代、物质来源等特征综述及对其成矿动力学背景、成矿机制的探讨,结果表明:二者的成矿类型、含矿斑岩体化学组成、矿体产状形态、围岩蚀变分带、成岩成矿时间等具有相似性,矿化均受小斑岩体控制,岩控特征明显。沙坪沟钼矿化的高品位、大储量与其发育的爆破角砾岩、更充分的"流体化作用"、较长时间的热液活动及矿化斑岩体的侵位空间等因素密切相关。二者具有相似的小岩体成大矿的成矿机制,即与含矿小岩体同源同成因的深源浅成的花岗岩基在深部发生分异演化,为浅部的含矿小斑岩体提供大量的热液和矿物质,在小斑岩体头部(或浅部)、以上和以外更大范围的构造岩或围岩中成矿。

Shapinggou and Jinduicheng are superlarge small intrusion type deposits which located on the East Qinling-Dabie molybdenum metallogenic belt. Comparative study which on the geological features, mineralogenetic epoch, material source, Mineralization dynamics background and small intrusion metallo- genie mechanism etc. show some results as following： Two deposits have similarity in many respects such as metallogenic type, Chemical composition of ore-bearing porphyry body, alteration distribution, time consistency of diagenetic and mineralization etc. The mineralization of two deposits is controlled by the small porphyry. The high grade and large reserves molybdenum mineralization in Shapinggou molybdenum deposit are attributed to the blasting breccia, a longer period of time of the hydrothermal activity and the emplacement space of porphyry. The two deposits have a similar metallogenic mechanism of small intru- sion mineralization. The Yanshanian deep-hypabyssal granitoids which are homologous with the small ore- bearing intrusion occurred differentiation and evolution in deep. A large amount of hydrotherm and mineral substance that from the granitoids emplaced to the head （or the shallow） of the porphyry or the outside contact zone.