A-Type Granites with the Character of Enrichment and Loss with Particular Reference to Both Suites of the Yanshan, North China and Wulunguhe, Northwest China

XU Baoliang, WANG Shiguang, HAN Baofu, YAN Guohan, HE Zhongfu

(Department of Geology, Peking University, Beijing, 100871)

Abstract:: Two suites of A-type granites with the character of alkaline- oversaturation are discovered in both of the Yanshan region, East China and the Wulunguhe region, the Xinjiang Uygur autonomous region. The Yanshan's A-type suite occurs in sitting of within-plate in tectonic, with character of Poor Nb, low (epsilon)_Nd(T) and high (epsilon)_Sr(T), the Wulunguhe's one are distributed over a late-organic sitting, being poor Nb, high (epsilon)_Nd(T) and low (epsilon)_Sr(T). Geology, petrology and data of major-trace-elements for the granites are summed, analysis results of Sm-Nd and Rb-Sr isotope are reported, derived-materials and subdivision for them are discussed in the paper. Two kinds of sources of derived-material, that one is enriched but another is lost, are implicated by these data for the A-type granites of both regions of the Yanshan and the Wulunguhe.
Key words:: North and Northwest China;A-type Granites; derived-materials;subgroup

(R.D.1997-12-05 P.D.1998-04-20 Vol.34 No.2-3 pp.352-362)