Re-Os dating of gold-bearing arsenopyrite of the Maoling gold deposit, Liaoning Province, Northeast China and its geological significance

摘要

The Maoling gold deposit, one of the large gold deposits in eastern Liaoning Province, NE China, is an ar-senopyrite-disseminated gold deposit with a resource of approximately 25 t An and an average An grade of 3.2 g/t. Six arsenopyrites closely related to An mineralization of the Maoling gold deposit are dated by Re-Os technique define a Re-Os isochron with an age of 2316 +-140 Ma, which suggests that the deposit was formed In the Paleoproterozoic era rather than in the Indosinian period as some early researchers suggested. High initial ~(187)Os/~(188)Os ratio of 1.32 +- 0.48 indicates a crustal derivation of the ore-forming material of the deposit, which may be derived from rocks of the Gaixian formation of the Liaohe Group. Furthermore, the result also implies that the age of the Gaixian Formation in the Maoling district is older than 2316 +- 140 Ma.