云南维西-兰坪地区水系沉积物地球化学异常特征及找矿潜力

Geochemical Characteristics of Stream Sediment and Prospecting Potential of Weixi-Lanping Area in Yunnan Province

云南维西—兰坪地区处于中—新生代碎屑岩、碳酸盐岩建造,区内NNW、近SN走向的主构造线反应了以喜山期为主的切穿岩石圈地幔的深大断裂活动,大规模的走滑和冲断推覆及拉伸作用形成岩石圈规模的分层折离和滑脱构造,引起岩石圈部分熔融及软流圈上涌,与碎屑岩、碳酸盐岩建造完成一系列变质作用、叠加改造等成矿作用,形成了以Cu、Pb、Zn为主的多金属喷流—沉积型矿床,具备大型—超大型矿床的找矿前景。为进一步指导区内多金属矿找矿工作,结合该区相关地质工作成果,分析了区域成矿地质背景,并分别从地球化学场、地球化学背景场、元素组合特征等方面讨论了区内水系沉积物地球化学特征;在此基础上对区内已划分的八宝山、富隆厂、玉狮山、华昌山等4处找矿远景区的水系沉积物异常特征进行了分析,并结合工程验证结果,分析了各远景区的找矿潜力,供区内进一步开展以Cu、Pb、Zn为主的多金属矿找矿勘探工作参考。

Weixi-Lanping area in Yunnan Province is belongs to Mesozoic-Cenozoic clastic rocks and carbonatite formation,the NNW-direction and near SN-direction main tectonic lines are formed primarily by the deep faulting activity of cutting through the lithosphere mantle,and it is mainly for Himalayan period. The layered fold and slippage structures with lithosphere scale are formed by the strike-slip effect,trust nappe effect and tension effect with large scale,the partial melting of lithosphere and asthenosphere upwelling are caused,and they are taken part in the series of mineralization effects such as metamorphism effect,superposition reconstruction effect,etc.,together with clastic rock and carbonate rock,so the polymetallic jet-sedimentary type deposit mainly for the elements of Cu,Pb and Zn,which show that the prospecting potential of large-super large scale deposit is existed in the area. In order to provide some basis for the prospecting work of polymetallic deposit in the area,combing with some related geological working results of the area,the regional metallogenic geological background is analyzed,and the stream sediment geochemical characteristics of the area is discussed from the aspects of geochemical fields,geochemical background fileds and elements combination characteristics; based on the above analysis results,the prospecting potential areas of Baobaoshan,Fulongchang,Yushishan,Huachagnshan are delineated,besides that,the stream sediment characteristics of the prospecting potential areas are studied in depth,and the prospecting potential of them are also discussed based on some related anomaly engineering verification results. The above analysis results related to the stream sediment geochemcial characteristics and prospecting potential of Weixi-Lanping area can provide some reference for the further prospecting and exploration work in the area.