西藏谢通门县雄村矿集区综合信息找矿模型及靶区预测

摘要

雄村铜金矿集区位于南拉萨地块南缘的冈底斯斑岩铜矿带,资源潜力大(仅查明的铜金属资源量超过250万吨、伴生金金属资源量超过250吨、伴生银金属资源量超过1100吨)、成矿地质背景特殊.通过对雄村矿集区的勘查和研究成果的系统分析,本文从矿床地质特征、地球物理特征、地球化学特征、遥感特征等四个方面进行了详细的归纳总结,分析了各类成矿要素的特征及内在联系.以找矿勘查为宗旨,扩大资源量为目的,建立了综合信息找矿模型.找矿模型显示,早、中侏罗世含矿斑岩和雄村组凝灰岩是主要的赋矿岩石,钾硅酸盐化、钠化-钙化、黄铁绢英岩化、青磐岩化是主要蚀变类型,Cu-Au-Ag元素地球化学异常是重要的地球化学找矿标志,矿体产出受NW、EW向的断裂构造控制,地面磁测的高磁异常及低磁异常、遥感蚀变异常(钾硅酸盐化蚀变、绢云母化蚀变和地表铁染)及线-线和线-环交切结构是主要的地球物理和遥感找矿标志.利用构建的综合信息找矿模型,在雄村矿集区共圈定出了3个A类找矿靶区(A-1,A-2和A-3),4个B类找矿靶区(B-1,B-2,B-3和B-4)和2个C类找矿靶区(C-1和C-2),并对各找矿靶区进行了评价.%The Xiongcun copper-gold ore district is situated in the Gangdise porphyry copper belt located on the south margin of the Lhasa terrane. It has the characteristics of the great prospecting potential (more than 2.5 million tons of copper resources, 250 tons of gold and 1100 tons of silver), and special geological background. Through the comprehensive analysis of the exploration and the existing research results in the Xiongcun ore district, this paper makes a detailed summary from four aspects of geological characteristics, geophysical characteristics, geochemical characteristics and remote sensing characteristics, and analyzes the characteristics and internal relations of various metallogenic conditions. The authors have established a comprehensive information prospecting model with the aim of searching for ore deposits and expanding the quantity of resources. Prospecting model shows the Early and Middle Jurassic porphyry and the surrounding tuff are the main ore-bearing rock. The K-silicate alteration, sodic-calcic alteration, phyllic alteration and prolitic alteration are the main alteration type. Cu-Au-Ag element geochemical anomaly is an important indicator of geochemistry. The orebodies are controlled by NW and EW trending faults. Ground magnetic survey of high or low magnetic anomalies and remote sense alteration anomalies (K-silicate alteration, sericite alteration and ferric contamination) as well as linear and ringlike structures are the main indicators of geophysical and remote sensing, respectively. The authors delineated three Class A prospecting targets (A-1, A-2 and A-3), four Class B prospecting targets (B-1, B-2, B-3 and B-4) and two Class C prospecting targets (C-1 and C-2) in the Xiongcun area based on the comprehensive information prospecting model. Meanwhile the authors evaluated each prospecting target area.