Compositions of olivine from the Wajilitag mafic-ultramafic intrusion of the Permian Tarim Large Igneous Province, NW China: Insights into recycled pyroxenite in a peridotite mantle source. (March 2019)

• Record Type: Journal Article
• Authors: Jin, Shengkai; Zhang, Zhaochong; Cheng, Zhiguo; Xie, Qiuhong; Fei, Xianghui; Santosh, M.; Wang, Fangyue
• Is Part Of: Journal of Asian earth sciences. Volume 171(2019)
• Page Start: 9
• Page End: 19
• Publication Date: 2019-03
• Subjects: Olivine trace elements -- Recycled pyroxenite -- Mantle source -- Tarim Large Igneous Province; Earth sciences -- Asia -- Periodicals; Sciences de la terre -- Asie -- Périodiques; Earth sciences; Asia; Periodicals; 555.05
• DOI: 10.1016/j.jseaes.2018.11.023
• Languages: English
• ISSNs: 1367-9120

Abstract

Graphical abstract: Highlights: There is evidence for the existence of recycled pyroxenites in a peridotite mantle source. The Wajilitag mafic-ultralmafic intrusion formed under high oxygen fugacity conditions. The maximum crystallization temperature of the Wajilitag intrusion was from 1350 °C to 1190 °C. The Wajilitag intrusion does not have good potential for Fe-Ti-V mineralization. Abstract: The Tarim large igneous province (TLIP) comprises a complex suite of lithologies including voluminous ferrobasalts, although the petrogenetic relation of these rocks is still poorly understood. In this study, we report the chemical compositions of olivine in two types of olivine pyroxenites (porphyritic and coarse-grained) from the Wajilitag mafic-ultramafic intrusion in the northwestern TLIP, aiming to characterize the mantle sources of magmas. Olivine in the porphyritic olivine pyroxenites shows low 100 * Mn/Fe (∼1.3) and Mn/Zn (<13) ratios, whereas that in the coarse-grained olivine pyroxenites is characterized by markedly higher ratios of 100 * Mn/Fe (>1.9) and Mn/Zn (>14), suggesting a heterogeneous mantle source beneath the Wajilitag area. The low olivine V/Sc values (<1.5) in the two types of olivine pyroxenites reflect high oxygen fugacity conditions during magma crystallization. The maximum temperatures of crystallization of porphyritic olivine pyroxenites and olivine pyroxenites estimated based on the Al-in-olivine thermometer are 1350 °C and 1190 °C, respectively. A comparison of the results from our study in terms of mantle source and oxygen fugacity suggests less potential for metallogeny in this region, as against the Panxi area in the Emeishan Large Igneous Province.