Metallogenic Characteristics And Regularity Of Ore Formation Of The Pengshan Tin-polymetallic Ore Field,Jiangxi, China

Pengshan ore field is located in De’an, Jiangxi province. For its good ore-forming condition,10more large and medium-sized deposits and40more ore occurrences have been proved up till now. Unfortunately, favorable metallogenic regions forecasted by traditional metallogenic theory are not ideal verified by engineering prospecting effect. Consequently, the regional mineral prospecting entered the bottleneck period. Based on former field geological investigation and research achievement, we lucubrate a series of typical ore deposits and analysis their geochemical element characteristics. And then we generate the metallogenic characteristics of Pengshan ore field. Using new prospecting ideas, we summarized regional regularity of ore formation, and improved regional comprehensive metallogenic model.High differentiation granite rock mass is the dominant factor of the formation of the ore field. In addition, it is necessary for the ore formation that the stratum and ore controlling geological interface contain abundant muti-metal element. The controlling interface of Pengshan ore field contains lithologic interface and structural interface. The lithologic interface mainly distributed in feldspar quartz sandstone at the top of the Liantuo formation of Nanhua system and thick layer limestone at the bottom of the Doushantuo formation of Cambrian system.With good ore-forming conditions, mine distribution is very intensive and resources potential is great in Pengshan ore field. Till now, more than10large and medium-sized kinds of ore deposits and40more ore occurrence have been found here. Meanwhile, numerous structural interfaces were mainly distributed in the line between Huangjinwa and Peijialong tin ore in the west of the Pengshan ore field. The characteristic ore here is a series of fissure filling type deposit and fracture zone type deposit in NNE and NE to space distribution. An important metallogenic characteristic of Pengshan ore field is calcium silicon surface mineralization. The most important ore-forming space is between feldspar quartz sandstone at the top of the Liantuo formation of Nanhua system and thick layer limestone at the bottom of the Doushantuo formation of Cambrian system. The main deposits like Zengjialong, Jianfengpo, Honghuajian, and Poxi tin ore, and Zhangshiba lead zinc ore was occurred in this special stratigraphic position. Besides, including Hongxifan and Huangjindong large fluorite ore, Peijialong and Xiabanshan tin ore, a number of metal and nonmetal deposits were distributed in the interface between Ordovician limestone and Silurian sandstone. Our research shows that the lead zinc ore is rich in radiogenic lead, and has high206Pb/204Pb and207Pb/204Pb ratio. Differently, the tin ore is poor in radiogenic lead, and has low206Pb/204Pb and207Pb/204Pb ratio. Tin ore has the same lead isotopic composition as two mica alkali feldspar granite. And this indicates that Sn came from two mica alkali feldspar granite. On the contrary, lead zinc ore has the same lead isotopic composition as pyrite in sedimentary formation in Nanhua system which indicates minerals matter like Zn and Pb were mainly from the ore-rich host rock.