發(fā)布時間：2018-05-13 21:06

  本文選題：退變質榴輝巖 + PT視剖面圖��； 參考：《巖石學報》2017年07期

【摘要】：滇西雙江縣勐庫地區(qū)的退變質榴輝巖經歷了多期退變質作用的改造,早期的平衡共生礦物組合難覓蹤跡。應用傳統(tǒng)的石榴石-單斜輝石(GC)溫度計、石榴石-單斜輝石-多硅白云母(GCP)壓力計進行變質作用的PT條件估算存在許多不確定性。本文應用魏春景等(2009)依據(jù)MORB成分計算的PT視剖面圖上多硅白云母、石榴石、綠輝石的成分隨體系中PT條件的變化情況,估算了進變質的P=2.00~2.30GPa,T=420~460℃,相當于硬柱石藍片巖相—硬柱石-藍閃石榴輝巖相;峰期變質的P=3.35~4.46GPa,T=530~610℃,相當于硬柱石榴輝巖相;早期退變質的P=2.00~2.50GPa,T=470~540℃,相當于硬柱石-藍閃石榴輝巖相;中期退變質的P=0.95~1.43GPa,T=700~750℃,相當于角閃石榴輝巖相-高壓麻粒巖相。晚期退變質作用以出現(xiàn)大量的閃石類礦物為特征,可劃分為3個階段,并顯示了持續(xù)的降溫、降壓過程。結合區(qū)域地殼演化進程,本文詳細討論了上述P-T-t軌跡的地質意義。
[Abstract]:The retrograde metamorphic eclogite in Mengku area, Shuangjiang County, western Yunnan has undergone many retrograde metamorphic processes, and the early balanced symbiotic mineral assemblage is difficult to find. There are many uncertainties in the estimation of PT conditions for metamorphism by using the traditional garnet-clinopyroxene GC- thermometer and garnet-clinopyroxene-polysilicon Muscovite pressure gauge. Using Wei Chunjing et al. 2009) according to the change of composition of Muscovite, garnet and omphacite in the PT profile calculated by MORB with PT conditions in the system, the authors estimate the temperature of the retrograde metamorphic P _ (2.00) ~ 2.30GPA _ T _ (420C) ~ (460) 鈩，

本文編號：1884794