庐枞盆地北缘西湾大型铅锌矿的发现及其找矿标志

庐枞火山岩盆地是长江中下游重要的矿集区,以往的找矿重点是盆地内部的玢岩型铁矿。随着矿集区勘查工作的深入,盆地周缘多金属矿的找矿潜力日益受到重视。为了解决覆盖区地质信息少、找矿难度大的难题,从区域地质规律入手,对盆地北部边缘西湾地区的地质背景和重、磁异常进行深入研究,确定了主要找矿方向,利用重力、磁法、电法等综合物探手段,逐步确定了控矿要素,发现了主要赋存于基底地层-三叠系东马鞍山组角砾状灰岩中的西湾大型铅锌矿(4个主矿体初步估算资源量达97.4万t、Pb+Zn品位1.21%～2.74%)。该矿的发现,突破了以往对该区铅锌矿找矿潜力的认识,明确了东马鞍山组是该区重要的赋矿层位,进一步拓展了该区的找矿空间,对于类似地区的矿产勘查具有一定的借鉴意义。

Discovery and its prospecting marks of Xiwan large-scale Pb-Zn deposit in the north Luzong Basin

Luzong volcanic basin is an important ore concentration area in the middle and lower reaches of the Yangtze River, and the previous exploration focus is porphyrite type iron ore in the basin. With the development of the exploration work in the ore concentration area, more and more attention has been paid to the prospecting potential of the polymetallic deposits around the basin. In order to solve the problem of little geological information and difficult ore prospecting in the covering area, starting from the regional geological laws, the geological background, gravity and magnetic anomalies in Xiwan area, the northern edge of the basin, are studied in depth, the main ore prospecting direction is determined, and the ore control factors are gradually determined by using the comprehensive geophysical exploration methods such as gravity, magnetic method and electrical method, Xiwan large-scale Pb-Zn deposit mainly occurs in the Breccia-like limestone fracture zone of the basement strata-triassic Dongmaanshan formation(The resources of the four main ore bodies are estimated to be 974 thousand tons and the grade of Pb+Zn is 1.21 ~ 2.74%). The discovery of the deposit has broken through the previous understanding of the prospecting potential of the Pb-Zn deposits in the area, clarifies that the Dongmaanshan formation is an important ore-bearing horizon in the area, and further expands the prospecting space in the area. The paper also summarizes the methods and techniques of mineral exploration by comprehensive geophysical prospecting in overburden area, which has certain reference significance for similar areas.