Re-Os isotopic dating of chalcopyrite from the Abalieke copper-lead deposits in West Kunlun, China.

It is a very important and effective method of analyzing the ore-forming processes by taking advantage of geochemistry analytical approaches as well as traditional ways, such as testing the Re-Os, discriminating the paragenetic association of the minerals and the tectonic settings. Seven chalcopyrite and one pyrite samples from the main orebody of Abalieke Cu-Pb deposit are used for Re-Os dating. The chalcopyrite is associated with galenite and dolomite which contain 626 x 10(-9) similar to 14533 x 10(-9) of Re and 0.026 x 10(-9) similar to 0.36 x 10(-9) of Os respectively, and yield a Hercynina isochron age of 331.3 +/- 5.2Ma. High Re/Os ratio, low Os concentration and highly radiogenic Os isotopic ratios of these samples suggest that they are of crustal origin. The tectonic evolving shows that the southwestern margin of the Tarim block was a passive continental margin in the Late Paleozoic era. Because of the Paleo-Tethys ocean movement during Carboniferous, the depression basin are formed in margin of Tarim craton, comprised lead-zinc deposits in elastic rock-carbonate host stratum that cover up the Devonian. This Re-Os isotopic dating age of chalcopyrite is nearly closed with ore-hosted stratum. Our Re-Os result provides new evidences, showing that Abalieke Cu-Pb deposit experienced the syngenetic ore-forming process in Hercynina. Also this study gives important geochemical evidence on such issues: the lead-zinc deposits are mainly sedimentary formation-controlled type; the ore-forming elements mainly came from stratum; mineralization occurred in the joint position between Upper Devonian and Lower Carboniferous, while the rock in which mainly consist of sandstone and carbonatite formation. It can be seen that the tnetallogenic system of the copper-lead-zinc strata-bound deposits in carbonate rock has a certain complexity and provides wider space for further researches.