Post-collisional magmatism in Wuyu basin,central Tibet:evidence for recycling of subducted Tethyan oceanic crust  

作　　者：赵志丹 莫宣学 张双全 郭铁鹰 周肃 董国臣 王勇 

出　　处：《Science China Earth Sciences》2001年第S1期27-34,共8页中国科学（地球科学英文版）

基　　金：the National Key Project for Basic Research on Tibetan Plateau(G1998040800), the National Natural Science Fountain of China (Grant Nos. 49772107, 49802005, 40103003), Key Basic (9501101-3) and Special Projects on Tibetan Plateau (No. 200101020401) of t

摘　　要：The trachyte and basaltic trachyte and intruded granite-porphyry of Gazacun formation of Wuyu Group in central Tibet are Neogene shoshonitic rocks. They are rich in LREE, with a weak to significant Eu negative anomalies. The enriched Rb, Th, U, K, negative HFS elements Nb, Ta, Ti and P, and Sr, Nd and Pb isotope geochemistry suggest that the volcanic rocks of Wuyu Group originated from the partial melting of lower crust of the Gangdese belt, with the involvement of the Tethyan oceanic crust. It implies that the north-subducted Tethys ocean crust have arrived to the lower crust of Gangdese belt and recycled in the Neogene magmatism.The trachyte and basaltic trachyte and intruded granite-porphyry of Gazacun formation of Wuyu Group in central Tibet are Neogene shoshonitic rocks. They are rich in LREE, with a weak to significant Eu negative anomalies. The enriched Rb, Th, U, K, negative HFS elements Nb, Ta, Ti and P, and Sr, Nd and Pb isotope geochemistry suggest that the volcanic rocks of Wuyu Group originated from the partial melting of lower crust of the Gangdese belt, with the involvement of the Tethyan oceanic crust. It implies that the north-subducted Tethys ocean crust have arrived to the lower crust of Gangdese belt and recycled in the Neogene magmatism.

关 键 词：: TIBET Wuyu BASIN POST-COLLISION shoshonitic ROCKS geochemistry. 

分 类 号：P59[天文地球—地球化学]