黑龙江金厂铜金矿区晚三叠世—早侏罗世花岗杂岩锆石U—Pb定年和岩浆热演化史示踪

Zircon U—Pb dating and magmatic evolution history tracing of Late Triassic—Early Jurassic granitic complex in Jinchang Cu—Au deposit area,eastern Heilongjiang

黑龙江金厂铜金矿床地处兴蒙造山带的北东端,兴凯—延边中生代岩浆构造带北部。对该矿区花岗岩杂岩体开展锆石CL图像、U--Pb定年和演化史示踪,结果表明它较好地记录了该区晚三叠世早期—早侏罗世岩浆连续作用的热演化史。岩浆演化大致经历了6个阶段:岩浆房冷却结晶、早期岩浆缓慢结晶、岩浆上涌过程中快速结晶、主体花岗岩浆降温结晶、晚期岩浆热液结晶和残余岩浆热液结晶过程。整个岩浆演化过程至少经历了23Ma,呈现相对连续的岩浆就位过程。

The Jinchang Cu--Au deposit is located in the eastern edge of Xing--Meng orogenic belt,northern Xingkai--Yanji tectonic-magmatic belt. We introduce the zircon CL images,U--Pb dating and tracing of the magma evolutionary history on the granitic complex in Jinchang Cu-Au deposit. The results show that it records the thermal evolution history of Late Triassic--Early Jurassic continuous magmatism well in this area. The magma evolution has undergone approximately six stages,including of the cooling crystallization of magma chamber,the slow crystallization of early stage magma,the fast crystallization during emplacement process of magma,the cooling crystallization of main granitic magma,the crystallization of late stage magma-hydrothermal fluid and the crystallization of the remainder magma-hydrothermal fluid. The whole process appeared relative continuous emplacement of magma,and lasted for 23 million years at least.