滇中禄劝九龙巨晶方解石矿床地质特征与成因

Geological characteristics and Genesis of Jiulong giant crystal calcite deposit in Luquan county,Central Yunnan province

滇中禄劝九龙方解石矿床是云南省规模最大的方解石矿床,以产出巨晶方解石矿为特点。本文在系统的野外地质调查和勘查评价基础上,分析了九龙巨晶方解石矿床的基本地质特征和控矿因素,探讨其成因。结果表明,区内方解石矿体呈层状、似层状及大脉状产于下二叠统茅口组(P1m)灰岩中,层控特点明显;成矿受围岩岩性和断裂的联合控制,开放空间后生热液充填交代成矿特点突出,属层控热液型矿床,新生代印度欧亚板块碰撞造山有关的陆内构造转换成矿可能是其关键机制。

Jiulong giant crystal calcite deposit is the largest calcite deposit in Yunnan province.Systematic field investigation has been made and basic geological characteristics and ore-control factors analyzed.Calcite ore bodies occur in layered,layeroid body or big vein within limestone of Lower Permian Maokou formation(P1m)showing clear stratibound characteristics.The calcite deposit is controlled by both lithology of the wall rock and fault with obvious hydrothermal filling feature.It is a stratibound hydrothermal deposit.Intra-continental tectonic transformation related to Cenozoic Indo-Eurasian plate collision progeny may be the key ore-forming mechanism of the deposit.