Northeast Jiangxi Taqian-Fuchun Metallogenic Belt Magmatite Time Limit and Sequence Division and Its Significance

It is a fatal challenge to the traditional cognition, which the W and Cu deposits distribute in the south and north regions of Jiangxi Province respectively, when the super Cu-W deposit in Zhuxi area was discovered recently, which attracts domestic researchers' attention and their interests in restudying geology of Taqian-Fuchun metallogenic belt in Zhuxi area that provides pivotal proofs for phenomenon of the south W deposit extends to the north region of the area. The recent discovery of the super Cu-W deposit in the Zhuxi area of northeast Jiangxi has challenged the belief that W and Cu deposits are distributed in the south and north regions of the province respectively and has led to a renewed interest in analyzing these areas again. The metallogenesis types in the Taqian-Fuchun metallogenic belt are complicated with multiple ores. For instance, Cu, W, Mo and Au are related to various igneous rocks, with some diagenesis. To address geological issues, such as the tectonic evolutional setting and ore material origins, which need to be solved urgently, the zircon U-Pb isotopic method of LA-ICP-MS was utilized and is reported in this paper in order to date the ore-related magmatic rocks. The results show that there were at least three periods of magmatism and two stages of metallogenesis in the belt. The three periods of magmatism include 850 Ma and 160 Ma granodiorites and for the lamprophyre veins, 146 Ma granites. Two stages of metallogenesis are the Taqian skarn-type W-Mo deposit and the Yuexing skarn-type Cu polymetallic deposit related to the 160 Ma granites, and the Zhuxi skarn-type Cu-W deposit related to the 146 Ma granites. Thus, considering previous regional data, the hypothesis from this study is that the ore-related magmas of Neoproterozoic and Jurassic in the belt were derived from the same magma chamber and the latter was inherited from the former. The porphyry granite and aplite veins formed in 145 Ma are the indicators of Cu-W deposit.