内蒙古自治区牙克石市西尼气林场安山岩锆石LA-MC-ICP-MS U-Pb定年及地质意义
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摘要
内蒙古自治区牙克石市西尼气林场一带出露的面积型安山岩,前人多划为早白垩世次火山岩或早白垩世的浅成侵入岩。本次安山岩U-Pb测年结果为226.0±1.9 Ma,为晚三叠世的产物,是大兴安岭中北部地区首次识别出三叠纪安山岩。结合地质特征,将其划为晚三叠世浅成侵入岩,说明在三叠纪大兴安岭中北部存在火山活动。本次测年结果对大兴安岭中北部火山岩地区面积型安山岩及安山玢岩的归属划分具有参照意义。
Area-type andesite exposed in Xiniqi forest farm,Yakeshi City, Inner Mongolia Autonnomous Region, the predecessors were mostly classified as early Cretaceous subvolcanic rocks or early Cretaceous hypabyssal intrusive rock.The U-Pb dating results of andesite are 226.0±1.9 Ma, it is a product of the Late Triassic. This is the first time that the Triassic andesite has been recognized in the north-central part of the Greater Khingan Range. Combining geological characteristics, it was classified as Late Triassic hypabyssal intrusive rocks. It shows that there are volcanic activities in the north-central part of the Triassic Greater Khingan Range. The results of this dating has referential significance for classification of area-type andesite and andesite porphyrite in volcanic rock area of north-central Greater Khingan Range.
Area-type andesite exposed in Xiniqi forest farm,Yakeshi City, Inner Mongolia Autonnomous Region, the predecessors were mostly classified as early Cretaceous subvolcanic rocks or early Cretaceous hypabyssal intrusive rock.The U-Pb dating results of andesite are 226.0±1.9 Ma, it is a product of the Late Triassic. This is the first time that the Triassic andesite has been recognized in the north-central part of the Greater Khingan Range. Combining geological characteristics, it was classified as Late Triassic hypabyssal intrusive rocks. It shows that there are volcanic activities in the north-central part of the Triassic Greater Khingan Range. The results of this dating has referential significance for classification of area-type andesite and andesite porphyrite in volcanic rock area of north-central Greater Khingan Range.
引文
[1]潘桂堂,肖庆辉,陆松年,等.中国大地构造单元划分[J].中国地质. 2009,43(2):36-1
[2]纪政,葛文春,杨浩,等.大兴安岭中段晚三叠世安第斯型安山岩:蒙古-鄂霍次克大洋板片南向俯冲作用的产物[J].中国地质. 2009,43(2):36-1
[3]张连昌、英基丰、陈志广,等,大兴安岭南段三叠纪基性火山岩时代与构造环境[J].岩石学报,2008,24(04):911-920.
[4]薛刚,骆剑英,刘金玉,等.大兴安岭中南段中生代火山岩特征及成因[J].内蒙古科技与经济,2006,(4):100-102.
[5]程银行,杨俊泉,刘永顺,等.大兴安岭敖包查干地区安山岩年代学、地球化学研究[J].2012,35(2):118-127.
[2]纪政,葛文春,杨浩,等.大兴安岭中段晚三叠世安第斯型安山岩:蒙古-鄂霍次克大洋板片南向俯冲作用的产物[J].中国地质. 2009,43(2):36-1
[3]张连昌、英基丰、陈志广,等,大兴安岭南段三叠纪基性火山岩时代与构造环境[J].岩石学报,2008,24(04):911-920.
[4]薛刚,骆剑英,刘金玉,等.大兴安岭中南段中生代火山岩特征及成因[J].内蒙古科技与经济,2006,(4):100-102.
[5]程银行,杨俊泉,刘永顺,等.大兴安岭敖包查干地区安山岩年代学、地球化学研究[J].2012,35(2):118-127.