Mineral reactions and geothermobarometry in a suite of granulite facies rocks from Paderu, Eastern Ghats granulite belt: A reappraisal of the P-T trajectory |
| |
| Authors: | Supratim Pal Sankar Bose |
| |
| Institution: | (1) Department of Geological Sciences, Jadavpur University, 700 032 Calcutta, India |
| |
| Abstract: | High Mg-Al spinel-sapphirine granulites, orthopyroxene-bearing quartzofeldspathic granulites, two pyroxene-bearing mafic granulites
and metapelitic gneisses are exposed around Paderu, Eastern Ghats Belt. Geothermobarometry in orthopyroxene-bearing quartzofeldspathic
granulites and mafic granulites indicate near isobaric cooling through 90°C from ca. 720°C to 630°C, at 8.0 kbar. However,
signatures of ultrahigh temperature metamorphism are recorded from the mineralogy and reaction textures in the high Mg-Al
granulites. Mineral reactions deduced in this work, when combined with others described by Lalet al (1987) from the same area and plotted in an appropriate petrogenetic grid in the system FMASO indicate an ACW path comprising
a high dT/dP prograde arm reaching Pmax − Tmax = 9.5 kbar, ∼ 1000°C, followed by near-isobaric cooling down to 9 kbar, 900°C and subsequent decompressive reworking. |
| |
| Keywords: | Mineral reactions geothermobarometry Paderu Eastern Ghats ACW P-T trajectory |
| 本文献已被 SpringerLink 等数据库收录！ |
|
