摘要
对黑龙江尚志一面坡地区固安屯组砂、板岩中火山碎屑岩的夹层晶屑凝灰岩进行LA-ICP-MS锆石U-Pb同位素定年和地球化学分析。结果表明,岩石Si O2含量为63.43%~75.01%,相对较高,主要为英安质和流纹质晶屑凝灰岩,属于钙碱性系列和高钾钙碱性系列;具有富集大离子亲石元素Rb、K等,而亏损Sr元素;轻稀土富集,重稀土亏损,有较明显的负铕异常,具有火山弧岩浆成分特点。主要获得晶屑凝灰岩,加权平均年龄为258.0±1.6 Ma（MSWD=0.113）,代表固安屯组上部火山碎屑岩夹层的形成年龄。此结果表明,在黑龙江尚志一面坡地区发育的固安屯组的形成时代为晚二叠世。
Zircon U-Pb ages and geochemical characteristics of crystal tuff intercalated in sandstone and slate in Gu＇ antun Formation of Yimianpo of Shangzhi,Heilongjiang Province were determined. The crystal tuff is mainly dacitic and rhyolitic in nature,and contains Si O2（ 63. 43% ~ 75. 01%）,belonging to calc-alkaline series and high-K calc-alkaline series. Trace elements of the crystal tuff are characterized by the enrichment of Rb,K,and depleted in Sr. The REE patterns demonstrate strong enrichment in LREE and depletion in HREE,and negative anomaly in Eu. They have the characteristics of magmatic component from volcanic arc. Zircon U-Pb isotopic dating is 258. 0 ± 1. 6 Ma（ MSWD = 0. 113）,which represents the forming age of the crystal tuff in the Gu＇ antun Formation as the Late Permian.
出处
《世界地质》
CAS
2016年第1期28-39,共12页
World Geology
基金
中国地质调查局项目(1212011120329)资助
关键词
固安屯组
凝灰岩
锆石U-PB定年
地球化学
尚志一面坡
黑龙江省
Gu＇ antun Formation
crystal tuff
zircon U-Pb dating
geochemistry
Yimianpo of Shangzhi
Heilongjiang Province
