Compositions of Olivine from the Mafic-Ultramafic Complexs in Eastern Tianshan, Xinjiang and Implications to Petrogenesus: Taking the Huangshandong and Tulargen Complexes as an Example
This paper takes Huangshandong and Tulargen complexes for examples and carries out mineral chemistry tests of fresh olivine from different lithologies. Modeling of olivine fractional crystallization and sulfide segregation show that the parental magma for Huangshandong complex has experienced 19% olivine fractional crystallization and extensive sulfide segregation (~0.3%). Re-equilibration of the early formed olivine crystals with trapped liquid can account for the variations of olivine compositions. The Tulargen complex has experienced 9% olivine fractional crystallization and extensive sulfide segregation (~0.5%).