Geochemistry of Granitoid Rocks from Zhejiang Province and Crustal Evolution-I. Phanerozoic Granitoid Rocks

摘要

The Phanerozoic granitoid rocks include the Caledonan, Indosinian and Yenshanian granitoid rocks. The existence of Caledonian and Indosinian granites was evidenced by zircon U-Pb ages. The study of the characteristics of major, trace and rare-earth elements, isotopic composition and petrogenesis for the granitoid rocks has been made. The Caledonian and In- dosinian granites were derived from partial melting of the Proterozoic basement rocks and the two tectonic activities were weak. The yenshanian granitoid rocks were derived from mixing of man- the and crustal materials. It implies that the crustal accretion took place in Mesozoic time.