Experimental Study on Crystallization of Plagioclases from a Granodioritic Melt at High Temperature and High Pressure

• 责任者：Xia Weiben (Laboratory for Study of the Earth’ s Interior and Geofluids ; Guiyang Institute of Geochemistry ; Chinese Academy of Sciences ; Guiyang 550002 ; China) ; Tang Hongfeng
• 刊名：Journal of Mineralogy and Petrology
• 出版年：2010
• 卷期：30(1)
• 关键词：斜长石 ; plagioclase ; A型花岗岩 ; A-type granite
• 页码：p.22-25
• 图表：3 illus., 4 tables, 1 photo, 12 refs.
• 分类号：0801
• issnNo：ISSN1001-6872
• isbnNo：CN51-1143/TD

The results of crystallization experiments of a granodioritic melt, at conditions of 500 ~2 000 MPa, 650 ~750 ℃ and H₂O-unsaturated or-saturated, showed that, at 500 MPa and H₂O-saturated, the plagioclases began to crystallize at 675 ℃, and that pressure, temperature and H₂O content had obvious impact on the crystallization and composition of plagioclases.The SiO₂ contents in residual melt with crystallization of plagioclases were higher than those without the present of plagioclases. Therefore, the preliminary experimental study on the major element compositions suggested that the A-type granitic magma in East Junggar could be derived from the crystallization differentiation of the granodioritic magma in the same region.