斑岩Cu-(Mo-Au)矿床的成矿构造环境及勘查意义

Metallogenic tectonic settings of porphyry Cu-(Mo-Au) deposits and their exploration significance:An overview

斑岩矿床是重要的矿床勘查目标。斑岩矿床的成矿构造环境研究有助于确定斑岩矿床的战略勘查方向。斑岩矿床形成的成矿构造环境包括板块汇聚边缘、大陆转换板块边界、陆内造山环境和非造山环境。本文重点对斑岩矿床在汇聚边缘和大陆转换板块边界的成矿构造环境及其勘查意义进行初步总结。构造变化对斑岩矿床的形成起到触发作用。微弱和中等程度的转换挤压应力最有利于岩浆的集聚、上升和就位。岩浆侵入可以是在广阔的转换挤压断层带内或在其周围局部呈引张的地区集中出现。对于斑岩矿床战略勘查方向而言,应注意研究区域走滑断层与侵入体的关系,加强对地表浅部喷气蚀变的识别。在我国西南地区已勘查发现的5个斑岩成矿带中,应注意沿区域走滑断裂构造方向开展找矿。从成矿构造环境与哀牢山-红河构造带对比来看,鲜水河-小江断裂带可能是西南地区新的斑岩矿床勘查区。

The porphyry deposits as an important exploration target are not the products originated from typical island-arc volcanism.The metallogenic tectonic settings of porphyry deposits consist of the plate convergent margin,continental transform plate boundary,and intracontinental orogenic and anorogenic settings.The present paper gives a general review of the metallogenic tectonic settings of porphyry deposits including the plate convergent margin and continental transform plate boundary,and their exploration significance.The structural variations may serve as a trigger for the formation of the porphyry deposits,and slight and moderate transpressional stress may be most favourable for the concentration,ascent and emplacement of magmas from the lower crust.The magmatic intrusion tends to occur within or around the broad transpressional fault zones.For mineral exploration strategies in southwestern China,particular attention is drawn to the regional strike-slip fault zone,with the emphasis on the Xianshuihe-Xiaojiang fault as potential prospects.