秦岭地区印支期钼矿化特征及找矿前景  

Indosinian Mo mineralization in Qinling area and prospecting potential

作　　者：胡海珠 李诺[2] 邓小华[2] 陈衍景[2] 李毅 

机构地区：[1]河南省有色金属地质勘查总院,河南郑州450052 [2]北京大学造山带与地壳演化教育部重点实验室,北京100871

出　　处：《中国地质》2013年第2期549-565,共17页Geology in China

基　　金：国家973项目(2006CB4035008);自然科学基金项目(40425006)资助

摘　　要：秦岭地区印支期钼矿床包括3种类型:碳酸岩脉型、断控石英脉型及斑岩型。碳酸岩脉型钼矿床与火成碳酸岩密切相关,矿体以含钼碳酸岩脉形式产出,成矿元素出现特殊的Mo+U+REE组合,以黄龙铺和黄水庵钼矿为典型代表。断控石英脉型钼矿受断裂控制明显,矿体以含钼石英脉形式产出,部分蚀变岩亦含矿。该类矿床具有与造山型矿床类似的矿体地质和成矿流体特征,属造山型矿床系列的中高温、中深成端元。典型实例包括外方山石英脉型钼矿田(纸房、前范岭等)、大湖金钼矿床、马家洼金钼矿床等。斑岩型钼矿以温泉钼矿床为代表。该类矿床与印支期中酸性小斑岩体密切相关,矿化呈细脉状、细脉浸染状产出,围岩蚀变包括钾化、绢英岩化、绿泥石化、绿帘石化、碳酸盐化等。综合区域地质情况及已有找矿勘查成果,指出秦岭造山带最北缘的碳酸岩-碱性岩带是寻找碳酸岩脉型钼矿的有利地区;华北克拉通南缘马超营断裂以北、三宝断裂以南有利于断控石英脉型钼矿的产出,其中小秦岭和熊耳山地区可出现石英脉型的Au-Mo矿化;强调应注重对东秦岭地区印支期花岗岩及其钼矿的找矿评价工作。Three types of Indosinian Mo mineralization can be observed in the Qinling area, namely carbonatite- type, fault-controlled quartz vein type and porphyry type. Carbonatite-type Mo deposits are represented by the Huanglongpu and Huangshuian deposits. They are spatially and genetically associated with magmatic carbonatite, and the ore bodies are present as Mo-bearing carbonatite veins, with specific Mo＋U＋REE mineralization. Fault- controlled quartz vein type Mo and Qianfanling controlled quartz Mo deposits）, veins, and the deposits are represented by the Waifangshan Mo ore district （composed of Zhifang Dahu Au-Mo deposits and Majiawa Au-Mo deposits. They occur as fault- hydrothermally altered wail rocks can be mineralized, either. Such deposits share similar geological and fluid inclusion features with the orogenic type deposit, and are regarded as its medium to high temperature endmembers. Porphyry-type Mo deposits, represented by the Wenquan Mo deposit, are associated with Indosinian intermediate-acid granite porphyry, and molybdenite crystals occur as veinlets or veinlet-disseminations. Typical porphyry type hydrothermal alterations include potassic alteration, phyUic alteration, chloritization, epidotization and carbonation. It is concluded that the carbonatite-alkali rocks in the northernmost part of the Qinling Orogen are in favor of carbonatite-type Mo mineralization, the area between Machaoying fault and Sanbao fault in the southern margin of the North China Craton is favorable for fault- controlled quartz-vein type Mo mineralization, and quartz vein type Au-Mo deposits can be found in Xiaoqinling and Xiong＇ershan regions. Emphasis should be placed on Indosinian granite and related Mo mineralization in East Qinling area.

关 键 词：印支期 钼矿化 成矿预测 秦岭 

分 类 号：P618.65[天文地球—矿床学]