【作者】 郭保健；

【导师】 毛景文； 王志光；

【作者基本信息】 中国地质大学（北京） ， 矿物学、岩石学、矿床学， 2006， 博士

【摘要】 本论文在对东秦岭区域地质背景和中生代主要矿床类型进行总结的基础上,选择了该地区最近几年发现的汝阳东沟超大型钼矿、洛宁沙沟银铅矿、内乡银洞沟银铅矿及镇平秋树湾铜钼矿等为重点,开展了成矿年代学及矿床地球化学等方面的研究,并对部分相关的花岗岩体、花岗斑岩体开展成矿年代学研究。系统总结了东秦岭地区中生代金属矿床组合特征与时空分布规律,反演了该地区中生代以来的构造演化与成矿作用,取得了以下主要成果和认识:1、重新划分了东秦岭中生代金属矿床的类型及矿床组合。以成矿事件为主线,划分了印支晚期(220 Ma左右)与幔源流体成矿作用有关的碳酸岩脉型钼矿;晚侏罗世140 Ma左右与中酸性I型斑岩体有关的钼铜多金属矿床组合;早白垩世130Ma～110Ma与斑岩体有关的钼矿床、浅成热液金矿及受构造与流体控制的脉状矿床组合类。2、在典型矿床研究方面:1)确定了北秦岭秋树湾铜钼矿146 Ma的平均模式年龄和147 Ma的等时线年龄,这是北秦岭中生代金属矿床中第一个可靠的成矿年龄。秋树湾铜钼矿的形成时代与近年获得华北地块南缘的主要钼矿床及扬子北缘和长江中下游的主要铜钼矿的形成时代一致,为中国东部第二期大规模成矿作用的产物,反映了中生代中国东部的成矿作用具有统一性。2)确定了华北地块南缘区东沟超大型钼矿的含矿母岩—东沟斑岩体的侵位年龄为112 Ma,钼矿的模式年龄为116 Ma,其地球动力学背景对应于中国东部中生代岩石圈大减薄过程。3)确定了熊耳山沙沟银铅锌矿的年龄为134.5 Ma,与矿区内蒿坪沟花岗斑岩的年龄(133 Ma)及区域上的花山花岗岩基的年龄(130.7±1.4 Ma)接近,表明其为同一成岩成矿事件的产物。4)对北秦岭银洞沟银铅锌矿的深部进行了矿床与矿床地球化学研究。表明为一中温热液矿床,流体向深部CO2增多,盐度增大,成矿物质的源区主要来自二郎坪群小寨组地层,而含矿流体早期以来自深部的岩浆热液为主,在成矿的中晚期,有大气降水加入。3、在对东秦岭及邻区成岩成矿事件系统总结的基础上,对比了华北地块南缘和北秦岭中生代金属矿床组合的异同点,总结了东秦岭区域成矿规律,提出了进一步找矿方向。更多还原

【Abstract】 Based on the study of the regional geologic setting and the main Mesozoicmetallogenic types of the East Qinling, this paper studies the mineralization ages and thegeochemistry on the newly discovered typical deposits such as Donggou Mo deposit,Shagou Ag-Pb-Zn deposit, Yindonggou Ag-Pb-Zn deposit and Qiushuwan Cu-Mo deposit.Moreover, this paper summarizes the features of the Mesozoic metallic metallogenicassociations and spatiotemporal distribution regularities, and discusses the Mesozoictectonic evolution and mineralization of the area.The Mesozoic deposit types and metallogenic associations of the East Qinling orogenyare reclassified. According to the Mesozoic mineralizing events, this paper puts forwardthree deposit associations of the area: Mantle fluid-related Mo deposit associations formedat ca. 220 Ma;I-type porphyritic intrusions-related Mo-W-Cu-polymetallic metallogenicassociations formed at ca. 140 Ma;Porphyry-related Mo deposits, epithermal gold depositsand structurally controlled Au-Ag-Pb-Zn associations formed at 130 Ma to 110 Ma.Some significant data are obtained through the study on the typical deposits: 1) the146 Ma mean model age and 147 Ma isochron age of the molybdenites from theQiushuwan Cu-Mo deposit is the first reliable age of the mineralization of the NorthQinling orogeny, which is coincident to the second large-scale mineralization pulse of theNorth China and the Lower Yangtze Reach;2) the 112 Ma of the porphyry and the 116 Maof the molybdenites of the Donggou Mo deposit indicates that the deposit formed at thethird mineralization pulse of the East China when the lithosphere thinning occurred;3) the134.5 Ma age of the Shagou Ag-Pb-Zn deposit, similar to that of the related Haopinggouporphyry(133Ma) and Huashan batholith(130.7Ma), implies that they are the products ofthe same magmatic-mineralizing event;4) the geochemistry of the Yindonggou Ag-Pb-Zndeposit exhibits its host rock ore-forming substance derivation. Meantime, the ore bearingfluid in the early stage shows its magmatic derivation and some mixture of magmatic andmeteoric water in the later stage.更多还原