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通过岩相学和矿物成分特征及P-T计算结果,最近在阿勒泰以东喀拉苏附近发现了超高温变泥质麻粒岩,其矿物组合为石榴石+斜方辉石+矽线石+堇青石+尖晶石+黑云母+斜长石+石英等.斜方辉石具有高铝特点,其Al2O3含量高达8.7wt%,指示了超高温变质的条件,其峰期变质条件为:P=~0.80 GPa,T=~960℃.变质结构关系和P-T估算结果表明了一个峰期后近等压冷却的逆时针P-T轨迹.锆石U-Pb年龄结果(271±5 Ma)支持了该超高温变质事件发生于二叠纪.喀拉苏附近超高温变泥质麻粒岩的发现确认了阿尔泰造山带二叠纪超高温变质作用的存在,表明在二叠纪阿尔泰造山带南缘高热流伸展背景可能与二叠纪(270~280 Ma)塔里木地幔柱活动有密切成因关系.
Based on the petrographic and mineral composition characteristics and PT calculation results, ultra-high temperature and argillaceous granulites have recently been discovered near the Kelasu, east of Aletai. Their mineral assemblages are garnet, orthopyroxene, and sillimanite Bluestone + spinel + biotite + plagioclase + quartz, etc. The orthopyroxene has high aluminum content and its content of Al2O3 is as high as 8.7wt%, indicating the conditions of ultra-high temperature metamorphism. The peak metamorphic conditions are: P = ~ 0.80 GPa and T = ~ 960 ° C. The relationship between metamorphic structure and PT estimation shows the counter-clockwise PT trajectory of near-pressure cooling after a peak period.The result of zircon U-Pb age (271 ± 5 Ma) supported this super The high-temperature metamorphic event occurred in the Permian. The discovery of ultra-high temperature and variable argillaceous granulite near the Kelasu confirms the existence of the Permian ultra-high-temperature metamorphism in the Altay orogen, indicating that the high heat flux in the southern margin of the Permian Altay orogenic belt The extensional background may be closely related to the Permian plume activity (270 ~ 280 Ma).