藏南喜马拉雅北坡色龙地区二叠系基性火山岩的发现及其构造意义

Discovery and tectonic significance of Permian Basic volcanic rocks in the Selong area on the northern slope of the Himalayas, southern Tibet

摘要: 藏南喜马拉雅北坡二叠系基性火山岩位于聂拉木县色龙东山。岩石地球化学特征表明,无论是基龙组火山岩还是色龙群火山岩,都具有大陆拉伸-大陆裂谷环境火山岩系的主、微量元素地球化学特征。据此,判断两套基性火山岩的性质和喷发构造环境相同。该区二叠纪大陆拉伸-裂谷火山活动标志着冈瓦纳超级古大陆开始裂离、解体。

Abstract: Permian basic volcanic rocks are located in the Eastern Mountains of Selong,Nyalam County,on the northern slope of the Himalayas,southern Tibet.Volcanic rocks of both the Jilong Formation and the Selong Group show major element ,trace element and REE geochemical characteristics of the volcanic series occurring in the continental extensional-rift environments.Therefore,the natures and eruptive tec-tonic environments of the two suites of volcanic rocks are the same.The Permian continental extensional-rift volcanism in the area marked the beginning of break-up of the supercontinent Gondwana.