Structure And Prospecting Direction For Dingjiashan Pb-Zn Deposit From The Central Fujian Rifting Zone, Southeast China

Youxi-Meishan area, with long history in mining, located in the Central Fujian Rifting Zone is the important ore-centralizing areas and prospective ore-forming areas of Cu, Pb, Zn Ag and other minerals. Dingjiashan Pb-Zn deposit is a large-scale marine volcanic (deposition)-metamorphism ore deposit formed in continental rift environment. The major layer of the orebody is the greenschist in Longbeixi formation of Sinian. The layer has undergone basic magma eruption and calcium deposition (sometimes with pelitic deposition) eruption-sedimentary cycles. Regional metamorphism occurring at tectonic Jinning orogeny made basic igneous rocks and some calcium sedimentary rocks turn into greenschist which was subjected to several superimposed hydrothermal alteration later. Dingjiashan Pb-Zn deposit is controlled by three main structural factors, fold belts, faults and unconformity surface. The orebody is mainly distributed along the main northeast-trending fracture, besides, the NE trending faults and a few smaller-scale NW trending faults are the main lead ore structures. The core of anticline, fracture intersections and unconformity are major ore-ore storage structures. In addition, the NE trending stock in the west (east) and the rock wall in the east (west) control the distribution of the ore body in a wider range. In the Mine area, galena and sphalerite-based multi-metal mine shows low resistance and high polarization characteristics, generally having a strong magnetic. However, according to the work, we find lead-zinc mine in this area can be expressed as the middle-high magnetic, weak magnetic or even non-magnetic, and it usually presents high polarization characteristics in the area with low resistance. Therefore, in the area without strong magnetic anomaly, it is needed to launch a new round of prospecting attempts in area with favorable controlling factors in conjunction with low resistance and high electrical polarization characteristics. In the target region (Ⅰ and Ⅱ) with weak magnetic or even non-magnetic anomaly and electrically with low resistance and high polarization, we find lead-zinc ore body according to the new prospecting ideas. Therefore, combining structural analysis, it is expected to achieve the desired prospecting effect skipping interval without mine.