摘要
大兴安岭中段中生代火山岩分布区植被覆盖严重,研究工作较周边地区相对落后,地层间接触关系不明,其填图单位的形成时代和构造背景问题是该地区研究的重点。因此本次针对海拉尔盆地呼伦湖东岸兴安群的满克头鄂博组和玛尼吐组的火山岩样品进行了LA-ICP-MS锆石U-Pb定年。测年结果显示满克头鄂博组的流纹岩的平均年龄为(160±1.3)Ma(MWSD=0.042),属晚侏罗世早期;玛尼吐组的安山岩的平均年龄为(147.6±1.7)Ma(MWSD=0.44),属晚侏罗世晚期。综合前人在该区域的中生代火山岩的测年及地球化学研究结果,表明海拉尔盆地中生代火山岩的形成时代是晚侏罗世—早白垩世,成因应与蒙古-鄂霍茨克洋闭合-造山后的伸展构造环境有关。
This paper puts focus on the formation time and structural background of the Middle Mesozoic volcanic rocks occurred in the Xingran Mountains. Therefore, samples of volcanic rocks from the Manketouebo Formation and Manitu Formation in the east bank of Hulun Lake, Hailaer basin are selected for zircon U-Pb LA-ICP-MS dating. It reveals that the sample from the Manke- touebo Formation yields a weighted average age of 160.0 Ma±1. 3 Ma （MWSD=0. 042） ,indica- ting that it is formed in the early epoch of late Jurassic period. The magmatic zircon from the Manitu Formation obtains a weighted average age of 147.6 Ma±1.7 Ma （MWSD=0.44） ,indi- cate that it is also formed in late Jurassic period. On the basis of previous dating ages of volcanic rocks and geochemical research data, it is considered that the Mesozoic volcanic rocks in the Hailaer basin are formed in the late Jurassic to early Cretaceous. These volcanic rocks are resulted from collision to post orogenic extension of Mongolia-Okhotsc oceans.
作者
裴圣良
黄明达
张恒利
张建强
霍超
黄少青
PEI Shengliang HUANG Mingda ZHANGHengli ZHANG Jianqiang HUO Chao HUANG Shaoqing(Guilin University of Technology,Guilin 541006,China General Prospecting Institute China National Administration of Coal Geology, Beijing 100039,China)
出处
《矿物岩石》
CAS
CSCD
北大核心
2017年第3期31-37,共7页
Mineralogy and Petrology
基金
基金项目:特殊用煤资源潜力调查评价(DD20160187)
