地质学报2016，Vol.90Issue(2)：250-266,17.
太行山北段木吉村髫髻山组安山岩锆石 U-Pb 年龄和Hf 同位素特征及其对区域成岩成矿规律的指示
Zircon U-Pb Geochronological and Hf Isotope Study on Tiaojishan Volcanic Formation,Mujicun,North Taihang Mountain and Implications for Regional Metallogeny and Magmatism
摘要
Abstract
The North Taihangshan Mountain area is one of the most important metallogenic belts in the East China.In this area,the Tiaojishan volcanic formation recorded the metallogenic-magmatism event times and resources in Mesozoic.The majority zircons from the andesite show the core-mantle texture.By LA-MC-ICP-MS U-Pb geochronology dating on the core and mantle of zircons,two group ages have been gained.One is younger,with two weighted average ages as 145.28 ±0.44Ma and 144.61 ±0.76Ma from two samples,which indicates the andesite forming time,and the other one is 2.08~2.65Ga from the core of zircons,which indicates the old crustal material being in the magma forming.LA-MC-ICP-MS in-situ Hf isotopic analysis of zircons gains two differentεHf(t) values ranges corresponded to the two group U-Pb ages.For the younger group (~ 145Ma),the εHf(t) values are in the range of - 25 to - 10,which suggests the volcanic rocks originated from the interaction process (mixing or mingling)between the enrich mantle and the old crust;for the other group (2.08~2.65Ga),theεHf(t) values are in the range of 0 to 10,which indicate the core of zircon derived from juvenile crusts same with the major crustal growth of the North China Craton (NCC),and suggests the old crust material have been involved during this magmatism.Combined with the geochemistry studies,the Tiaojishan volcanic rocks might originate from partial melting of an enriched mantle,contaminated by the old NCC crustal component en route,then emplaced after fractional crystallization. This volcanic event was formed in Mesozoic metallogenic-magmatism event,and it implicates the NCC tectonic changing by lithosphere extension in Late Mesozoic. Based on the geochronology data,we infer that there might be two major metallogenic events,one is characterized by the forming of porphyry Cu-Mo deposits,and the other one is characterized by the forming of Au deposits.关键词
太行山北段/木吉村/髫髻山组火山岩/锆石 U-Pb 年龄Key words
North Taihang Mountain/Mujicun/Tiaojishan volcanic rocks/U-Pb dating/Hf isotope引用本文复制引用
段超,毛景文,谢桂青,陈志宽,马国玺,王志敏,陈焘,李伟..太行山北段木吉村髫髻山组安山岩锆石 U-Pb 年龄和Hf 同位素特征及其对区域成岩成矿规律的指示[J].地质学报,2016,90(2):250-266,17.基金项目
本文受中国地质调查局地质调查工作项目（12120113093600）资助。 （）
