Petrogenic and metallogenic geochronology and its geological implications of Lianzhushan gold deposit, Jiayin, Heilongjiang Province.

Located in the northern Lesser Xing' an Range, the Lianzhushan deposit is an altered rock type gold deposit, host in the inner fractured zone of granite. To constrain its formation age and metallogenic geological setting, this paper carried out geochemistry research, LA-ICP-MS zircon U-Pb, and sericite 40Ar/39Ar dating on biotite monzogranite, and quartz diorite. The analytic results show that biotite monzogranite formed in the Middle Triassic (243. 7 +/- 1. 3Ma, MSWD = 0. 77, n = 12), which had been contaminated by the Early Palaeozoic (474 similar to 438Ma) and the Middle Permian (267 similar to 261Ma) magma during magmatic ascending; the quartz diorite formed in the Late Triassic (215. 3 +/- 1. 3Ma, MSWD =0. 35, n = 17); the sericites from pyritization phyllic altered ores have plateau age of 40Ar/39Ar at 194. 2 +/- 2. 0Ma, indicating that mineralization occurred in the Early Jurassic. Element geochemical characteristics show the Lianzhushan intrusive belong to metaluminous to weakly prealuminous, high potassium calc alkaline series, and have the geochemical characteristics of I-type granite, which enriched in light rare earth element ( LREE) and large ion lithophile element ( LILE) and relatively depleted in heavy rare earth element ( HREE) and high field strength element ( HFSE) with weak Eu anomalies. Combining the previous geochronology and regional evolution features of Lesser Xing' an Range-Zhangguangcai Range, the metallogenesis took place in a transition setting from late period of Xingmeng orogen to the subduction of Paleo-pacific oceanic plate, or the mineralization occurred in the extensional stage of the Xingmeng orogen.