辽宁永宁地区含金刚石闪长质岩石显微特征及金刚石来源探讨  

Microscopic characteristics of diamond-bearing dioritic rockin Yongning area, Liaoning province and discussionon source of the diamond

作　　者：杨献忠[1,2] 王爱国 周延[1,2] 徐华 徐敏成[1] 杨杰 YANG Xianzhong;WANG Aiguo;ZHOU Yan;XU Hua;XU Mincheng;YANG Jie(Nanjing Center,China Geological Survey,Nanjing 210016,China;Joint Research Centre for Circum-Pacific Strategic Mineral Resources,Nanjing 210016,China;Liaoning Sixth Geological Brigade Co.Ltd,Dalian 116200,Liaoning,China)

机构地区：[1]中国地质调查局南京地质调查中心,南京210016 [2]环太平洋战略矿产资源联合研究中心,南京210016 [3]辽宁省第六地质大队有限责任公司,辽宁大连116200

出　　处：《地质找矿论丛》2023年第2期185-196,共12页Contributions to Geology and Mineral Resources Research

基　　金：中国地质调查局项目“华东地区钨锡钴等矿产地质调查”(编号:DD20221688)、“钦杭成矿带武宁—平江地区钨铜多金属矿地质调查”(编号:DD20190153)联合资助。

摘　　要：辽宁永宁地区发育一套闪长质火山岩,该岩石中曾选获金刚石及其指示矿物,因此成为辽宁省金刚石第Ⅳ成矿带。通过对该岩石矿物组成及其显微结构构造特征研究,表明:①闪长质岩石中的斑晶斜长石具有环带结构;②橄榄石及金云母具有多世代性,且目估橄榄石+金云母含量在10%以上,局部更为富集;③出现“橄榄石+金云母+石榴石”与“斜长石+辉石+角闪石”不平衡的矿物组合;④发现橄榄石有碎斑结构和金伯利岩角砾。初步认为,永宁地区的闪长质岩浆在上升过程中捕获了早先已形成的金伯利岩并与之发生熔融混合作用,金刚石来自于深部的金伯利岩。这一认识对该地区寻找金刚石原生矿具有启示意义。A set of dioritic volcanics occur in Yongning area,Liaoning province.Diamond and diamond-indicator minerals were picked out from the dioritic rock.Therefore,the dioritic rock belt becomes the diamond ore belt Ⅳ.Study on mineralogy,microscopic texture and structure of the rock shows that(1)plagioclase phenocrystal is characterized by ring structure,(2)olivine and phlogopite occur in many generations and visual estimation of olivine+phlogopite is>10%or more locally of total mineral constituent of the rock,(3)unbalanced mineral combination of olivine+phlogopite+garnet and plagioclase+pyroxene+hornblende occur in the rock,(4)clastic olivine phenocrystal and kimberlite breccia occur in the rock.It is believed that the ascending dioritic magma captured,melted and mixed the preexisting kimberlite.The diamond is derived from the deep kimberlite that will enlighten primary diamond prospecting in the area.

关 键 词：闪长质火山岩 斑晶斜长石环带结构 金刚石 金刚石指示矿物 金伯利岩 岩浆混合作用 辽宁永宁地区 

分 类 号：P588.14[天文地球—岩石学] P619.241[天文地球—地质学]