甘肃省漳县岩盐矿含矿地层特征与找矿方向

CHARACTERISTICS OF ORE-BEARING STRATA AND PROSPECTING DIRECTION OF SALT MINE IN ZHANGXIAN COUNTY,GANSU PROVINCE,CHINA

研究区位于西秦岭北缘断裂带漳县盆地内,通过对钻探成果资料和地质剖面资料研究,综合分析了漳县岩盐含矿地层特征和盐矿层赋存规律。结果表明漳县岩盐矿属内陆湖泊型沉积,受喜山运动控制影响。盐矿层主要赋存于新近纪上新世临夏组上段(N23)和中段(N22)灰(黑)色钙质泥岩、泥灰岩中,圈出含盐矿层4层。结合区内盐矿沉积旋回、赋存规律等特征,圈定2个找矿靶区,对下一步漳县岩盐矿勘查具有一定的指导意义。

A salt mine of reseach is located in Zhangxian basin of the northern margin fault zone of West Qinling Mountains.In this paper,the characteristics of ore-bearing strata of the mine have been analyzed comprehensively according to the drilling results and geological profile data.Then,the law of salt deposit occurrence in the mine has been summarized,with subsequent prospecting direction advanced.The study shows that the salt mine is a type of inland-lake deposit,influenced by the Himalayan movement control and formed by residual seawater supply,evaporation and deposition after the formation of extensional rifting.During the prospecting,the area is divided into 5 sedimentary cycles and 4 layers of salt-bearing ore layers are circled.It has been found that salt layer mostly occurs in the upper(N23)and middle(N22)ash(black)color calcareous mudstone and marl of the Upper(N23)and Middle(N22)Linxia Formation of the Neogene,that the eastern,western and southern areas are mainly restricted by the paleogeographic environment,and that the northern part is mainly controlled by the F4 fault.With the foregoing efforts,two prospecting target areas can be delineated in this section,combining with the exploration degree and the characteristics of salt deposit cycle and occurrence law in the area,it can be inferred that the drilling depth in the western part of the deposit is generally shallow(within 600m),and the main salt-bearing ore layer is not exposed and controlled.Two prospecting target areas can be circled in this section,and the potential of deep control prospecting by drilling is huge.It is of guiding significance for the next step of rock salt exploration in Zhangxian County.