摘要
川西地区早震旦世苏雄组火山岩以流纹岩为主,夹有少量玄武岩。苏雄组流纹岩的SHRIMP锆石UPb年龄为803±12Ma,代表了火山岩的喷发年龄。系统的岩石化学资料表明,苏雄组火山岩是一套典型的弱碱性双峰式火山岩,形成于大陆裂谷环境。扬子块体西缘康滇裂谷非常类似于现代与地幔柱活动有关的高火山活动型裂谷,支持约825Ma华南地幔柱模式。
The Neoproterozoic Suxiong volcani c rocks in western Sichuan consist of～90%rhyolite and ～10%basalt.SHRIMP U-Pb zircon age determination indicates that the Suxiong volcanics was erupted at(803±12)Ma.The volcanic rocks are of a typical mi ldly alkaline bimodal suite in terms of petrochemical characters,and are thought to be formed in a continental rifting environment.With striking similarity to the present-day high-volcanicity rift,such as Ethiopian rift,the Kan gdian rift was most likely triggered by a mantle plume,supporting the existence of a Neoproterozoic mantle plume ben eath South China.
出处
《地球化学》
CAS
CSCD
北大核心
2001年第4期315-322,共8页
Geochimica
基金
国家杰出青年科学基金49725309
中国科学院知识创新项目KZCX2101
中国科学院"九五"重点项目AKZ951B1413
"攀登计划"预选项目95预25
"国家重点基础研究发展规划"项目G1999043201
