辽源建安—个新的晚白垩世火山群的确定

Determination of a new Late-Cretaceous volcano group in Jian'an of Liaoyuan

在辽源建安火山群内运用全岩K-Ar测年方法首次获得老道山、双山、毛山及四甲山火山锥体玄武岩的年龄分别为(99.28±1.59)Ma、(91.70±1.67)Ma、(82.55±1.94)Ma、(82.18±2.37)Ma,可确认建安火山群是当前中国东北乃至中国东部规模最大的晚白垩世火山群。这一结果为探讨中国东部晚白垩世时期的构造演化提供了精确的年代学资料,同时,该火山群的形成与寻找无机成因的油气藏具有重要联系,也为该地区蓝宝石矿及伴生宝石矿的初查工作提供了依据。

The whole rock K-Ar dating method was used to date the basalts from Laodaoshan-Shuangshan-Maoshan-Sijiashan volcanic cones in Jian＇an volcano group of Liaoyuan,which are （99.28 ± 1.59） Ma,（91.70 ±1.67） Ma,（82.55 ± 1.94） Ma and （82.18 ± 2.37） Ma,respectively.The results show that Jian＇an volcano group was the largest Late Cretaceous volcano group in Northeast China or even in East China.This investigation provided exact chronological data for Late Cretaceous tectonic evolution in East China.The formation of this volcano group had close relationship with the inorganic origin reservoir,and also provided basis for prospecting of sapphire or its associated deposits.