Geological features and origin of gold deposits occurring in the;Baotou-Bayan Obo district, south-central Inner Mongolia, People's;Republic of China

doi:10.1016/S0169-1368(02)00069-0

CORC > 中国地质调查局 > 中国地质调查局 > 中国地质科学院矿产资源研究所

	Geological features and origin of gold deposits occurring in the;Baotou-Bayan Obo district, south-central Inner Mongolia, People's;Republic of China
	Nie, FJ 3; Jiang, SH ; Su, XX ; Wang, XL
刊名	ORE GEOLOGY REVIEWS
	2002
卷号	20 期号:3-4 页码:139-169
关键词	geologic features ore genesis alkaline magmatism gold deposits Baotou-Bayan Obo Inner Mongolia
ISSN号	0169-1368
DOI	10.1016/S0169-1368(02)00069-0
英文摘要	Located at western portion of northern margin of North China craton, the Baotou-Bayan Obo district is one of the most important Fe-REE-Nb and An metallogenic provinces in China. Presently, about 52 gold deposits and prospects have been discovered, explored and mined, among which Shibaqinhao, Laoyanghao, Houshilma, Saiyinwusu, Wulashan and Donghuofang are the most important ones. All these gold occurrences can be subdivided into three groups (or types) according to its host rocks: (1) hosted by Archean high-grade metamorphic rocks; (2) hosted by Proterozoic sedimentary rocks; (3) hosted by or related to Hercynian alkaline intrusive rocks. The first group contains the Shibaqinhao, Laoyanghao and Houshihua gold deposits. Gold mineralization at these three deposits occurs within Archean amphibolite, gneiss and granulite as gold-bearing quartz veins and veinlet groups containing native gold, electrum, pyrite and chalcopyrite. The Saiyinwusu deposit belongs to the second group, and occurs within Proterozoic sandstone, quartzite and carbonaceous slate as quartz veins and replacement bodies along the fracture zones. Pyrite, marcasite, arsenopyrite, native gold and electrum are identified. The third group includes the Wulashan, Donghuofang and Luchang deposits. Gold mineralization at these three deposits occurs predominantly within the Hercynian alkaline syenite or melagabbro stocks and dyke swarms or along their contacts with Archean metamorphic wall rocks as K-feldspar-quartz veins, dissemination and veinlets. Pyrite, galena, chalcopyrite, native gold and calaverite are major metallic minerals. delta(34S) value of sulfides (pyrite, galena and pyrrhotite) separates from groups 1 and 2 varies from - 4.01 parts per thousand to - 0.10 parts per thousand and - 3.01 parts per thousand to 2.32 parts per thousand, respectively. delta(34)S values of Archean and Proterozoic metamorphic wall rocks for groups 1 and 2 deposits range from - 20.2 parts per thousand to - 17.0 parts per thousand and - 15.8 parts per thousand to 16.2 parts per thousand, respectively. The values are much lower than their hosted gold deposits. All these pyrite separates from Hercynian alkaline intrusions associated with the gold deposits show positive 634S values of 1.3 parts per thousand to 4.8 parts per thousand, which is higher than those Precambrian metamorphic wall rocks and their hosted gold deposits. 634S values of the sulfides (pyrite and galena) from the Donghuofang and Wulashan deposits (group 3) increase systematically from veins ( - 14.8 parts per thousand to - 2.4 parts per thousand) to the Hercynian alkaline igneous wall rocks (2.8 parts per thousand to 4.8 parts per thousand). All of these deposits in groups 1, 2 and 3 show relatively radiogenic lead isotopic compositions compared to mantle or lower crust curves. Most lead isotope data of sulfides from the gold ores plot between the Hercynian alkaline intrusions and Precambrian metamorphic wall rocks. Data are interpreted as indicative of a mixing of lead from mantle-derived alkaline magma with lead from Precambrian metamorphic wall rocks. Isotopic age data, geological and geochemical evidence suggest that the ore fluids for the groups 1 and 2 deposits were generated during the emplacement of the Hercynian alkaline syenite and mafic intrusions. The Hercynian alkaline magma may provide heat, volatiles and metals for these groups 1 and 2 deposits.;Evolved metamorphic fluids produced by the devolatilization, which circulated the wall rocks, were also progressively involved in the alkaline magmatic hydrothermal system, and may have dominate the ore fluids during late stage of ore-forming processes. Most of these gold deposits hosted by Archean high-grade metamorphic rocks occur at or near the intersections of the NE- and E-W-trending fracture systems. The ore fluid of the group 3 deposits may have resulted from the mixing of Hercynian alkaline magmatic fluids and evolved meteoric waters. The deposits are believed to be products of Hercynian alkaline igneous processes along deep-seated fault zones within Archean terrain. (C) 2002 Elsevier Science B.V. All rights reserved.
学科主题	矿床地质
WOS关键词	SULFUR ISOTOPE ; HEBEI PROVINCE ; ORE-DEPOSITS ; OF-CHINA ; EVOLUTION ; LEAD ; GEOCHEMISTRY ; CONSTRAINTS ; GENESIS ; MODEL
WOS研究方向	Geology ; Mining & Mineral Processing
语种	英语
出版者	ELSEVIER SCIENCE BV
WOS记录号	WOS:000177978400004
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/37512]
专题	中国地质科学院矿产资源研究所
作者单位	1.Chinese Acad Geol Sci, Inst Mineral Deposits, Beijing 100037, Peoples R China. 2.Inner Mongolian Geol Survey, Hohhot 010020, Peoples R China. 3.中国地质科学院矿产资源研究所
推荐引用方式 GB/T 7714	Nie, FJ,Jiang, SH,Su, XX,et al. Geological features and origin of gold deposits occurring in the;Baotou-Bayan Obo district, south-central Inner Mongolia, People's;Republic of China[J]. ORE GEOLOGY REVIEWS,2002,20(3-4):139-169.
APA	Nie, FJ,Jiang, SH,Su, XX,&Wang, XL.(2002).Geological features and origin of gold deposits occurring in the;Baotou-Bayan Obo district, south-central Inner Mongolia, People's;Republic of China.ORE GEOLOGY REVIEWS,20(3-4),139-169.
MLA	Nie, FJ,et al."Geological features and origin of gold deposits occurring in the;Baotou-Bayan Obo district, south-central Inner Mongolia, People's;Republic of China".ORE GEOLOGY REVIEWS 20.3-4(2002):139-169.