SUN Yong1, LI Yong-jun1, YANG Gao-xue1, WANG Ran1, ZHANG Sheng-long1, YI Shan-xin1, SUN Yu1, WANG Jun-nian2
1. Earth Science & Resources College of Chang'an University, Xi'an 710054, China;
2. No. 7 Geological Survey Team, Xinjiang Bureau of Geology and Mineral Resource Exploration, Wusu, Xinjiang 833000, China
Abstract: Geochemistry studies were conducted to explore properties and geological characteristics of Middle Silurian volcanic rocks in the west of the Xiemisitai Mountain, West Junggar. The results indicated that the igneous rocks are characterized by high Si, Sr, Ba and Mg# (55~75), Sr/Y (28~59), Ba/La (17.52~49.88), and K/Na (0.33~0.66), enrich large ion lithophile elements (LILE) and deplete high field strength elements (HFSE) especially, Nb, Ta, Ti, and show weak negative Eu anomalies (δEu=0.84~0.99). These features are analogous to those of sanukite in the Setouchi volcanic belt, Japan, indicating they originatied from the subduction slab with partial melting of mantle sourced metasomatites. The occurrence of the volcanic rocks and the similar slab-related adakite in this area implied that the northern West Junggar had been affected by hot, subduction-related regime in the Middle Silurian-Early Devonian, and helped to further understand the nature and the tectonic evolution of the Boshchekul-Chingiz island arc in the West Junggar.
Keywords: sanukite Middle Silurian metasomatism of slab melts subduction West Junggar
*Corresponding Author, E-Mail: yongjunl@chd.edu.cn
Bulletin of Mineralogy, Petrology and Geochemistry Vol. 34, No.2, 2015, page 387-394
