摘要
对大别山铙钹寨超镁铁岩体中石榴辉石岩的研究表明 ,铙钹寨岩体经历了从尖晶石—富铝辉石相 (750℃、1.1GPa)、尖晶石—石榴石相 (850℃、1.5GPa)到麻粒岩相 (80 0℃、0 .85GPa)的变质演化。该岩体与南大别超高压变质杂岩的演化过程存在很大差异 ,它基本上处于一较高温地热体制之下 ,属于南大别俯冲陆壳的上盘杂岩。铙钹寨岩体及其它超镁铁岩体的普遍麻粒岩化与区域麻粒岩相的相关性可能说明大别变质基底已被彻底改造 ,北大别 (安徽省内 )
The study of garnet pyroxenite reveals that the ultramafic block in Raobazhai within the Dabie Mountains is of metamorphic origin rather than a slice of primitive mantle. It underwent an evolutional process from spinal_Al_rich pyroxene facies (750℃, 1.1 GPa) through spinal_garnet facies (850℃, 1.5 GPa) to granulite facies (800℃, 0.85 GPa). The metamorphic history of the block is obviously different from that of ultrahigh_pressure complex in the southern Dabie Mountains. It may represent the upper rock of subducting continental crust of the southern Dabie Mountains characterized by a high geothermal gradient. The relationships of the granulitization of Raobazhai and other ultramafic blocks to regional granulite facies metamorphism suggests that the Dabie basement has been thoroughly reformed, and the high_grade metamorphism of the northern Dabie Mountains in Anhui Province is only a mirror of the post_Indosinian granulite facies event.
出处
《岩石矿物学杂志》
CAS
CSCD
北大核心
2001年第1期11-20,共10页
Acta Petrologica et Mineralogica
基金
原地质矿产部青年地质学家基金资助项目! ( 96 0 8)成果之一
关键词
变质超镁铁岩
麻粒岩相
石榴辉石
变质作用
演化
变质成因
the Dabie Mountains
Raobazhai
meta_ultramafic rock
granulite facies
geological correlation
