广东连平大顶铁矿区石背岩体LA-ICP-MS锆石U-Pb年龄及地质意义  

LA-ICP-MS zircon U-Pb dating of Shibei pluton at Dading iron mine area in Lianping,Guangdong and its geological significance

作　　者：林小明 李宏卫 黄建桦 娄峰[2] 

机构地区：[1]广东省地质调查院,广东广州510080 [2]中山大学地球科学与地质工程学院,广东广州510275

出　　处：《中山大学学报（自然科学版）》2016年第1期131-136,共6页Acta Scientiarum Naturalium Universitatis Sunyatseni

基　　金：国土资源部中国地质调查局公益性行业基础地质调查专项资金资助项目(1212011220047;12120113063100;1212010511106)

摘　　要：广东连平大顶铁矿被誉为华南第一大铁矿床,为华南地区最为典型的矽卡岩型矿床。对大顶铁矿区与成矿作用有关的石背岩体粗粒斑状黑云母花岗岩和中粒斑状黑云母花岗岩进行LA-ICP-MS锆石U-Pb定年,获得的同位素年龄分别为(174.3±3.6)Ma(MSWD=1.6)和(176.9±4.3)Ma(MSWD=2.6),表明石背岩体侵位时代为早侏罗世晚期-中侏罗世早期,是燕山第一幕岩浆活动之产物。石背岩体形成于早中生代古太平洋板块向欧亚板块俯冲过程中的挤压构造背景,其物源主要来自于地壳,为壳内物质熔融-岩浆固结而成,与佛冈岩体相似,均为陆壳改造型(S-型)花岗岩。Dading iron mine in Lianping, Guangdong province is well known as the largest iron ore deposit, and is also the most typical skarn type deposit in South China. The LA-ICP-MS zircon U-Pb age of coarse-grain porphyritic biotite granite and medium-grain porphyritic biotite granite from Dading pluton, closely related to mineralization in Dading mining area, are （ 174. 3 ±3.6） Ma （ MSWD = 1.6 ） and （ 176. 9 ± 4.3 ） Ma （ MSWD = 2.6）, respectively, and it shows the emplacement age of Shibei pluton belonged to the early Jurassic-middle Jurassic, and it was the product of the first magma activity of yanshanian period. The Shibei pluton was formed in extrusion tectonic setting, in the process of subduction of the Pacific plate under Eurasian plate in the early Mesozoic. Its source mainly from crust, formed by crustal material melting and magma consolidation, similar to the Fogang pluton, is crustal transformation type （S-type） granite.

关 键 词：LA-ICP-MS锆石U-PB年龄 地质意义 大顶铁矿 石背岩体 

分 类 号：P581[天文地球—岩石学]