北大巴山平利穹窿南缘重晶石矿带地质特征及成矿条件分析  

Geological Characteristics and Metallogenic Conditions of Barite Ore Belt at South Margin of Pingli Dome in Northern Dabashan

作　　者：魏东[1,2] 陈西民 彭学军 

机构地区：[1]中国地质大学,北京100083 [2]陕西省地质矿产勘查开发总公司,陕西西安710054 [3]陕西省地质矿产勘查开发总公司第一分公司,陕西安康725000

出　　处：《西北地质》2016年第1期214-223,共10页Northwestern Geology

基　　金：陕西省平利县神仙台重晶石矿详查及资源储量核实

摘　　要：陕西秦巴地区钡资源丰富,大致呈南(镇巴-城口)、中(洛河-竹溪)、北(茨沟-赤岩)3条成矿带展布。平利穹窿南缘重晶石矿带(中带)沿着安康早古生代裂谷(O-S)中的平利穹窿(Pt3)南缘展布,地层区划属于紫阳-平利小区。赋矿层位震旦上统灯影组为白云岩、白云质灰岩夹硅质岩及含碳硅质板岩一套组合。矿层产出特征与区域构造以及沉积环境存在着重要的耦合关系。平利古陆南缘海槽凹陷带属半封闭海盆,火山(碎屑)岩基底构造为成矿提供了丰富的Ba、S物源,海水溶液由酸性演化至弱酸-弱碱性氧化环境时重晶石沉积成矿,矿床成因类型属与海底火山(沉积)活动有关的浅海沟槽沉积型重晶石矿床。The barium resources is very rich in Qinba area, Shaanxi Province, with 3 ore belts, that is South （Zhenba-Chengkou）, Middle （Luohe-Zhuxi） and North Belts （Cigou-Chiai）. The middle barite ore belt is located and spreaded along the south margin of Pingli Dome （Pt3） that was developed in the Ankang Eopalaeozoic rift （O- S）, and its strata belong to the Ziyang-Pingli Partion. The barite deposit is hosted Upper Sinian Dengying Formation, which is a set of dolomite, dolomitic limestone, siliceous rock and carbonaceous siliceous slate. The output characteristics of barite ore-layer have an important coupling relationship with regional tectonic and sedimentary environment. The trough depression at the south margin of Pingli paleo-land was a semi-closed oceanic basin, the volcano （clastic） rock basement structure provides a rich Ba, S source for mineralization. When the seawater solution evaluated from a- cidic to weak acid-alkalescent oxidation environment, the barite was deposited as mineral deposit. There- fore, this deposit belongs to the sedimentary barite deposit in shallow-water trench that was related tosubmarine volcano （sedimentary） activities.

关 键 词：平利穹窿 重晶石 地质特征 成矿条件 

分 类 号：P619.25[天文地球—矿床学]