摘要
根据新的调查和综合研究,南楼山组早期于建组剖面附近的四方顶子和玉兴屯获流纹岩全岩K-Ar同位素年龄176.1Ma和176.7Ma,近期又在建组剖面的北大湖二道沟和南大岭分别获得流纹岩和辉石安山岩的锆石U-Pb高精度年龄(174.0±3.4)Ma和(179.4±1.1)Ma,故南楼山组的时代可确认为早侏罗世晚期土阿辛期(Toarcian)。双丫子东山火山岩全岩K-Ar同位素年龄(195.0±5.01)Ma;官马金矿区火山岩全岩Rb-Sr等时线年龄(222±10)Ma,不应划入南楼山组或将其时代修定为晚三叠世。
According to the new survey and comprehensive study,the Nanloushan Sifangdingzi and Yuxingtun in the neighborhood of the section,rhyolite whole rock K-Ar isotopic age determination is 176.1 Ma and 176.7 Ma,recently,in the Erdaohu and Nandahu of the Beidahu of the section,high-precision zircon U-Pb ages determination of rhyolite and pyroxene andesite 174.0 ± 3.4 Ma and 179.4 ± 1.1 Ma,so,the age of Nanloushan Formation can be determined as the lToarcian of the early Jurassic period.Shuangyazi,Dongshan volcanic rock whole-rock K-Ar isotopic ages is195.0 ± 5.01 Ma;volcanic whole rock Rb-Sr isochronal age of the Guanma gold mining area is 222 ± 10 Ma,they should not be divided into Nanloushan Fomation or revised as the late Triassic age.
出处
《吉林地质》
2011年第3期25-30,共6页
Jilin Geology
关键词
吉林
中部地区
南楼山组
早侏罗世晚期
central part of Jilin Province
Nanloushan Formation
the end of the early Jurassic
