Geochemical Characteristics and SHRIMP U-Pb Age Significance of Diabase in Aketiekexie Moutain Area, East of Bogda, Xinjiang

Based on the study of diabase in Aketiekexie Mountain region, intraplate basalt characteristics(strong peraluminous and alkaline series), and illusion of the plate boundary(mainly caused by contamination of continental crustal material loss of the Nb, Ti high field strength elements) were identified. In addition, the REE distribution patterns of the diabase were four MM-type curves divided by Nd/Pm, Gd and Ho/Er, showing tetrad effect or quadruple effect. SHRIMP U-Pb dating results display two ages, which are upper intersection point age of (408±10)Ma in early Devonian, representing magma crystallization periods, and lower intersection age of (301±10)Ma, coinciding the thermal tectonic event in late Carboniferous. Combining with previous researches, Bogda orogenic belt belongs to rift tectonic setting rather than island arc environment. Bogda rift evolution first begins in the east section and the evolution is marked by diabase magma activities in early Devonian.