宁芜南段和睦山铁矿床地质特征及成矿作用研究

发布时间：2018-04-16 01:20

  本文选题：玢岩铁矿 + 矿床地质　； 参考：《中国地质大学(北京)》2015年硕士论文

【摘要】：和睦山铁矿床位于宁芜矿集区南部钟姑矿田内,其主矿体呈似层状或透镜状产于闪长玢岩岩体与中—上三叠统碳酸盐岩地层接触带及其附近围岩中,在宁芜矿集区具有典型性。作者在前人研究的基础上,对和睦山铁矿床进行了野外地质调研和镜下观察以及矿物学和地球化学分析工作,查明了铁矿床地质特征,分析了成矿作用过程,取得了一些成果和认识。野外调研和镜下观察表明,和睦山铁矿床矿体主要赋存在闪长玢岩岩体与中三叠统周冲村组碳酸盐岩地层接触带及其附近围岩中,其次是在黄马青组与周冲村组之间的假整合面以及闪长玢岩岩体中。矿石可分为阳起石—磷灰石—Ⅰ型磁铁矿和浅闪石—金云母—Ⅱ型磁铁矿两种主要类型。浅闪石较阳起石更富Al和Na而贫Si,且Ⅰ型磁铁矿呈浸染状,贫Ti和Al而富Mg,而Ⅱ型磁铁矿呈粗粒脉状,富Ti和Al而贫Mg,表明浅闪石—金云母—Ⅱ型磁铁矿阶段的成矿温度高于阳起石—磷灰石—Ⅰ型磁铁矿阶段。和睦山铁矿蚀变和矿化分带明显,从岩体到地层依次为:闪长玢岩→钠化闪长玢岩→金云母—阳起石岩→阳起石—磷灰石—Ⅰ型磁铁矿矿石→浅闪石—金云母—Ⅱ型磁铁矿矿石→(电气石)—浅闪石—金云母(角砾)岩→(阳起石)—金云母岩→大理岩化灰岩-角岩→灰岩-砂页岩。根据相互穿插关系、矿物组合和结构构造,将和睦山铁矿床的形成过程分为成矿前、主成矿和成矿后三个时期。成矿前期只有钠长石阶段,以钠长石对斜长石的强烈交代为特征。主成矿期可分为阳起石—磷灰石—Ⅰ型磁铁矿、浅闪石—金云母—Ⅱ型磁铁矿和赤铁矿三个成矿阶段。阳起石—磷灰石—Ⅰ型磁铁矿阶段主要形成浸染状矿石;浅闪石—金云母—Ⅱ型磁铁矿阶段以产出脉状磁铁矿矿石为特征。成矿后期可分为石英—黄铁矿阶段和碳酸盐阶段。石英—黄铁矿阶段以大量产出黄铁矿为特征,石英相对较少;碳酸盐阶段以晚期方解石对成矿前期、主成矿期各阶段矿物的叠加改造为特征。从论文资料来看,和睦山铁矿床是玢岩铁矿系列中的一个典型的中—高温气液交代充填型矿床。阳起石—磷灰石—Ⅰ型浸染状磁铁矿矿石是高温气液交代作用的产物,而浅闪石—金云母—Ⅱ型粗粒脉状磁铁矿矿石是高温矿液充填作用的产物。
[Abstract]:The Huoshan iron deposit is located in the Zhonggu ore field in the south of Ningwu ore concentration area. Its main orebody occurs in the contact zone between diorite porphyrite rock mass and the middle and upper Triassic carbonate strata and its surrounding rock, which is typical in Ningwu ore accumulation area.On the basis of previous studies, the authors have carried out field geological investigation, microscopic observation and mineralogical and geochemical analysis of the Hushan iron deposit, identified the geological characteristics of the ore deposit, and analyzed the metallogenic process.Some achievements and understandings have been made.Field investigation and microscopic observation show that the orebody of Huoshan iron deposit mainly occurs in the contact zone between diorite porphyrite and carbonate strata of Zhouchong village formation in the middle Triassic and its surrounding rock.The second is the pseudo-integration plane between Huangmaqing formation and Zhouchong village formation and diorite porphyrite.The ore can be divided into two main types: actinolite-apatite-鈪，

本文编号：1756676