THE GEOCHEMISTRY OF UPPER JURASSIC VOLCANIC ROCKS IN LONGQUAN,ZHEJIANG,AND THEIR ORIGIN

The author considers that the Upper Jurassic volcanic rocks in Longquan, Zhejiang,are represented by a sequence of K-poor and Ca-poor acid volc- anic rocks,belonging the calc-alkaline series.They are the product of eru- ption of the magma produced by partial melting of the sialic crust in act- ive continental-margin orogens.