Fluid inclusions in carpholite-bearing metasediments and blueschists from NE Oman; constraints on P-T evolution
Fluid inclusions in carpholite-bearing metasediments and blueschists from NE Oman; constraints on P-T evolution
European Journal of Mineralogy (April 2004) 16 (2): 221-233
- Arabian Peninsula
- Asia
- blueschist
- carpholite
- chain silicates
- fluid inclusions
- freezing
- high temperature
- homogenization
- inclusions
- isochores
- metamorphic rocks
- metamorphism
- metasedimentary rocks
- microthermometry
- Oman
- P-T conditions
- P-T-t paths
- phase equilibria
- salinity
- schists
- silicates
- temperature
- water vapor
Quartz and Fe-Mg-carpholite in metasediments formed under lawsonite-albite facies conditions in thrust sheets in NE Oman contain several types of fluid inclusion; most are two-phase at room T with an aqueous NaCl-H (sub 2) O or NaCl-MgCl (sub 2) -H (sub 2) O solution. Texturally early inclusions display a wide range of final melting and homogenization temperatures; some of the highest values (> 320 degrees C) are recorded for isolated inclusions in carpholite and quartz. In epidote-blueschist facies metasediments, many fluid inclusions in quartz are decrepitated, with most of the surviving inclusions being three-phase, CO (sub 2) -bearing, filled with a low salinity fluid with XCO (sub 2) < 0.05. It is considered that inclusions with high T (sub h) experienced post-entrapment stretching + or - loss of H (sub 2) O during exhumation.
