West Junggar is one of the hot study region in Central Asian Orogenic Belt （CAOB） in recent years，and have many ophiolitic mélange belts. With the deepening of the study，the alkali ocean island basalts （OIB） with different ages have been identified in ophiolitic mélanges. Studying on geochemical properties and Sr?Nd isotopic composition of Late Devonian pillow basalts within Karamay and Darbut ophiolitic mélanges，and the results show that the pillow basalts are characterized by alkaline affinity with high TiO2 （2.3%～3.8%） and P2O5 （0.38%～0.91%），low MgO （2.41%～4.97%），clear differentiation of LREE and HREE，(La/Yb)N = 5.1～14.5，no obvious Eu anomalies （Eu/Eu* = 0.96～1.1），Rb，Th and U enrichment and Ba，K，Sr depletion，and also no obvious Nb and Ta negative anomalies. Moreover，they have positive εNd(t)（3.3～4.4），and young model age （0.83～0.72 Ga），derived from depleted mantle source with partial melting of pyroxene riched peridotite or free olivine pyroxenite and hornblendite in a plume-related intra-oceanic seamount/oceanic island settings. This is obvious different from Tarim large igneous province （TLIP） which is characterized by continental intraplate and enriched mantle features. They are belong to two distinct isotopic geochemistry province，the one is southern province with enriched mantle isotopic composition，and the other is northern province with depleted mantle isotopic composition.
Yang Gaoxue Li Yongjun Tong Lili Li Ganyu Shen Rui. Geochemical features of Late Devonian alkali basalts in West Junggar and compared with magmatic rocks in Tarim large igneous provinces[J]. Chinese Journal of Geology, 2017, 52(1): 285-300.