华北克拉通南北缘三叠纪钼矿化类型、特征及地球动力学背景

华北克拉通南北缘是中国最重要的钼成矿带,特别是近年来在南北缘陆续发现了大量的钼矿床,显示了巨大的钼资源前景。其中三叠纪钼矿床的不断发现引人注目。在华北克拉通北缘及邻区三叠纪钼矿床在空间上总体呈EW向展布,矿床产出受区域东西向断裂控制,钼矿床的形成与三叠纪酸性侵入体关系密切,多产于花岗岩体中、斑岩体内外接触带或附近,矿床类型包括斑岩型和石英脉型。在华北克拉通南缘及邻区,三叠纪钼矿床总体上呈NW向展布,受区域NW向断裂控制,钼矿床的形成与晚三叠世酸性侵入体及碳酸盐脉有关,矿床产于斑岩体内及附近,矿床类型包括斑岩型、石英脉型及碳酸盐脉型。成矿年代学研究表明,华北克拉通北缘及邻区三叠纪钼矿主要形成于248~220Ma,而南缘及邻区三叠纪钼矿床主要形成于226~210Ma。其对应的成矿动力学背景为印支期华北板块与西伯利亚板块同碰撞造山过程和扬子板块与华北板块同碰撞造山过程。

Mineralizing types, geological characteristics and geodynamic background of Triassic molybdenum deposits in the northern and southern margins of North China Craton

The northern and southern margins of North China Craton are the important molybdenum metallogenic belts in China, and a lot of molybdenum deposits were discovered in these two belts in recent years, this indicate that these belts have a huge exploration potential. The Triassic molybdenum deposits catch geologist's eye. The Triassic molybdenum deposits distribute along the northern margin, southern margin and adjacent area of North China Craton. The molybdenum deposits are controlled by regional EW-, and NW-trending faults, and is associated with acid granites and carbonitite dykes in time and space. The molybdenum deposits are usually distributed in granite body, along the endo-or exo-contact zones of the ore-forming rock body, or nearby. The molybdenum deposits can be classified into two types: porphyry and vein type. The vein type deposits are divided into two subtypes: quartz vein and carbonitite vein type deposits. The geochronology data shows that the molybdenum deposits in the northern margin and southern margin of the North China Craton and adjacent area were formed in 248~220Ma, and 226~210Ma, respectively. The corresponding geodynamic background is the syn-collisional and post-collisional extension of the newly-amalgamated North China-Siberian plates during Indo-Chinese epoch, and syn-collisional setting of the amalgamated North China-Yangtze plates.