滇西北羊拉铜矿床里农矿段地球化学找矿研究

Geochemical Prospecting for Linong Ore Section of Y angla Copper Deposit in Northwest Yunnan

羊拉铜矿床位于金沙江构造结合带中部,是滇西北地区代表性矿床之一,该矿床为滇西北铜多金属成矿带上典型的后生叠加作用形成的斑岩-矽卡岩型矿床。本文通过野外观察及室内构造地球化学分析得出,各地层岩性在微量元素含量方面存在明显差异,围岩微量元素因子异常可较好地区分地层界线,尤其对里农组二段大理岩最为明显;中高温成矿元素组合异常均能较好地反映矿体的形态,且异常形态与断裂构造产状一致,反映矿体产出明显受构造的控制;中低温地球化学异常、低温地球化学异常的范围明显不同于高温地球化学异常,且异常分布面积更大;三者的对比分析,在平面上可以判断矿体的产状。

Yangla copper deposit which is one of the typical porphyry-skarn deposit lies in Jinsha river tectonic coalcscence zone of north west Yunnan. This work mainly studies structral geochemical genesis of deposit and prediction of deposit based on the data of field observation and lab analysis. Structral geochemical shows that stratigraphic boundary can be well defined by abnormal trace element factors of surrounding rock and its has obvious effect for the marble of the second part of Linong layer. The form of ore body can be well reflected by abnormal middle-high temperature ore-forming elements combination and abnormal form is same as the faultoccurrence. It shows that the ore form is controlled by structure. Middle-low temperature geochemical anomaly and low temperature geochemical anomaly is obviously different with the high temperature geochemical anomaly, it has more wide distribution area. Those three comparative analysis can be used to confirm the mode of occurrence of ore bodyon the plane.