摘要
双沟狗头坡花岗岩属高SiO2、K2O的过铝质A2型后造山(后碰撞)型花岗岩,形成于伸展构造背景下(地壳厚度<15km)。U-Pb锆石测年得到双沟岩体的年龄为235.4±1.4Ma。结合区域地质资料分析,双沟岩体的侵位时间和地球化学性质说明T2末期之前,金沙江-哀牢山洋盆业已闭合,碰撞造山期已经结束,研究区进入了造山带垮塌机制下后造山的伸展阶段。
The Goutoupo granite of Shuanggou belongs to the high SiO2,K2O peraluminous A2 type postorogenic(postcollision)Granite,formed in the extension structural setting(crust thickness<15km.According to the U-Pb dating of zircon,the age of Shuanggou rock boby is 235.4Ma±1.4Ma.In combination with the regional geological information,the emplacement period and geochemical nature of Shuanggou rock boby show thea the Jinshajing—Ailaoshan ocean basin was closed before T2 final period,the collision orogeny was ended,the postorogenic extension stage began under the collapse mechanism of orogene in the study area.
出处
《云南地质》
2012年第1期134-138,共5页
Yunnan Geology
基金
西北大学大陆动力学国家重点实验室科技部专项经费
中国石油化工股份有限公司重大基础攻关项目(YPH08006)
