新疆白杨河杨庄岩体侵入机制与成矿作用  

Mechanism of Magma Emplacement and Mineralization of Yangzhuang Pluton,Baiyanghe,Xinjiang

作　　者：庞星 张浩浩 鲁克改[1] 杨文龙[1] 陈浩[1] 张雷[1] PANG Xing;ZHANG Haohao;LU Kegai;YANG Wenlong;CHEN Hao;ZHANG Lei(Geologic Party No.216,CNNC,Urumqi,Xinjiang 830011,China)

机构地区：[1]核工业二一六大队,新疆乌鲁木齐830011

出　　处：《铀矿地质》2023年第5期804-815,共12页Uranium Geology

基　　金：国家自然科学基金项目(编号:41272100);“新疆和布克赛尔县白杨河矿床外围铀–多金属矿调查评价”(编号:201818-1)联合资助。

摘　　要：新疆白杨河杨庄岩体是西准噶尔重要的次火山岩体。文章通过对前人工作总结、地质调查、深部钻探查证以及样品采集分析等,探讨白杨河杨庄岩体的侵入机制。结果表明:杨庄岩体属于同源岩浆以脉动侵位的“内侵式”生长方式形成的复式岩体,其侵入机制可以划分为两期,其中第一期形成晚石炭世第三次侵入期次(西部岩体),分布在岩体下部及边缘;第二期形成晚石炭世第四次侵入期次(中东部岩体),分布在岩体上部;中东部和西部岩体地球化学特征没有明显差异性,两岩体均富Si、富K、Al弱过饱和、贫Fe、Mg;中东岩体构造比较发育,多组原生节理密集排列,为后期成矿热液富集提供了空间,西部岩体构造不发育,以碎裂岩为特征;中东岩体矿化特征明显,矿化主要产在岩体内及围岩接触带附近,西部岩体剥蚀深度较深,上部大部分被剥蚀掉,成矿条件相对较差。本区主要的工业铀、铍、钼矿体产于中东部岩体中。Yangzhuang pluton,located in Baiyanghe,Xinjiang,is a significant subvolcanic pluton in western Junggar.This paper discussed the intrusion mechanism of the Yangzhuang pluton based on the predecessor accomplishment,geological survey,deep drilling verification,and sample collection and analysis.The results showed that Yangzhuang pluton is a compound pluton formed by the pulse emplacement of homologous magma,and its intrusion process can be divided into two phases,the first phase occurred in the third intrusion stage of Late Carboniferous(western pluton),which is distributed in the lower part and edge of the pluton,and the second phase occurred in the fourth intrusion stage of Late Carboniferous(central and eastern pluton),which is distributed in the upper part of the pluton.There are no discernible differences in geochemical properties between rocks in the middle east and the west.Both rocks are rich in Si,K,and Al,but are unsaturated in Fe and Mg.The middle eastern pluton is well developed in structure,with many groups of primary joints densely arranged,allowing for the enrichment of ore-forming hydrothermal solution in the later period,whereas the western pluton is week in structure and characterized by cataclastic rocks.Mineralization characteristics of pluton are obvious in the middle east,and mineralization occurs primarily in the pluton and near the contact zone of surrounding rock.The erosion depth of the pluton in the west is deep,and most of the upper part was eroded,resulting in relatively poor metallogenic conditions;the main industrial uranium,beryllium,and molybdenum ore bodies in this area are found in the central and eastern part of the pluton.

关 键 词：杨庄岩体 两次侵入 铀、铍、钼矿体 

分 类 号：P588.13[天文地球—岩石学] P619.14[天文地球—地质学]