矿床地质2011，Vol.30Issue(1)：11-20,10.
内蒙古苏尼特右旗毕力赫大型斑岩型金矿床辉钼矿Re-Os同位素年龄及其地质意义
Molybdnite Re-Os isotope age of Bilihe large-size porphyry gold deposit in Sunid Right Banner of Inner Mongolia and its geological significance
摘要
Abstract
Situated in Sonid Right Banner of Inner Mongolia, the Bilihe gold deposit lies within the Caledonian hyperplasia orogenic belt sandwiched between North China north margin (Kangbao-Chifeng) fault and WenduermiaoXilamulun fault in the middle-eastern section of the Central Asian orogenic belt. The host rock in the Bilihe gold deposit is a set of neutral-acidic volcanic rocks-sedimentary rocks, which can be divided into andesites in the lower part and rhyolites with related clastic rocks in the upper part. The concealed gold-bearing sub-volcanic intrusive complex composed mainly of granodiorite porphyry-monzogranite porphyry is closely related to the mineralization. Four types of mineralization have been identified, namely quartz vein type, tectonic fracture zone altered rock type, explosion breccia type and porphyry altered rock type. The first three mineralization types are controlled by faults, breccia pipes (veins) and volcanic bodies as well as their supporting structures. The gold deposit belongs to the (sub)volcanic hydrothermal type, which has been subjected to intense erosion and hence only partially preserved. The most important mineralization type is the porphyry alteration type, and the proven resources of this type of mineralization account for more than 90 ％ of the total resources of the mining area. The porphyry type mineralization occurs in the inner- and exo-contact zone between hypo-volcanic complex body and overlying volcanic rocks as well as volcanic clastic rocks, especially in the inner-contact zone. It is the first time that a large-sized porphyry gold deposit was found in the northern margin of North China plate, i.e., the Bilihe large-size porphyry gold deposit in Sunid Right Banner of Inner Mongolia. In order to identify the porphyry gold (copper) metallogenic age, the authors used Re-Os isotope to test 6 molybdnite samples collected from the porphyry, which yielded the isochron age of (272.7 ± 1.6) Ma (MSWD = 0.57). Redefinition of the late Paleozoic ore-forming geological event of the Bilihe gold deposit has provided new evidence for the convergent plate structural system in the northern part of North China in late Paleozoic, recognized some basic geological problems of the northern part of North China, and given enlightenments in search for low temperature shallow-seated porphyry gold-polymetallic deposits in the magmatic arc environment of the middle-east segments of the Central Asian Orogenic Belt in late Paleozoic.关键词
地球化学/Re-Os年龄/辉钼矿/晚古生代/毕力赫金矿/内蒙古苏尼特右旗Key words
geochemistry/ Re-Os age/ molybdnite/ late Paleozoic/ Bilihe gold deposit/ Sonid Right Banner of Inner Mongolia分类
天文与地球科学引用本文复制引用
卿敏,葛良胜,唐明国,屈文俊,袁士松,赵玉锁..内蒙古苏尼特右旗毕力赫大型斑岩型金矿床辉钼矿Re-Os同位素年龄及其地质意义[J].矿床地质,2011,30(1):11-20,10.基金项目
本文得到国家危机矿山接替资源找矿项目"内蒙古自治区苏尼特有旗金曦金矿接替资源勘查"(项目编码200715011)、"晋东北-内蒙古中部地区火山岩型金多金属矿床成矿规律总结研究"(项目编码20089925)的资助 （项目编码200715011）
