文档共享_Beijing SHRIMP Center

你好,请

An Important Spreading Event of the Neo-Tethys Ocean during the Late Jurassic and Early CretaceousEvidence from Zircon U-Pb SHRIMP Dating on Diabase in Nagarze,Southern Tibet [查看] JIANGSihong、NIEFengjun、HUPeng、LIUYan

Widely distributed in Gyangze-Chigu area,southern Tibet,NW-and nearly E-W-trending diabase(gabbro)-gabbro diorite dykes are regarded as the product of the large-scale spreading of the late Neo-Tethys Ocean.In order to constrain the emplacement age of these dykes,zircons of two samples from diabases in Nagarze were dated by using the U-Pb SHRIMP method.Two nearly the same weighted mean 206Pb/238Uages were obtained in this paper,which are 134.9±1.8Ma(MSWD=0.65)and 135.5±2.1(MSWD=1.4),respectively.They not only represent the crystallization age of the diabase,but also documented an important spreading event of the Neo-Tethys Ocean during the late Jurassic and early Cretaceous.This dating result is of great significance to reconstruct the temporal framework of the late Neo-Tethys Ocean in the Qinghai-Tibet Plateau.