UNIDEF   23986
UNIDAD DE INVESTIGACION Y DESARROLLO ESTRATEGICO PARA LA DEFENSA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
ULTRAMAFIC XENOLITHS IN BASANITES FROM CERRO PILQUINIYEU CHICO, EXTRAANDEAN PATAGONIA, ARGENTINE.
Autor/es:
MOMTENEGRO, T.F.; PARICA, C.A; REMESAL M.B.; SALANI, F.M.
Lugar:
Heidelberg
Reunión:
Congreso; 24th Colloquium on Latin American Earth Sciences; 2017
Institución organizadora:
Universität Heidelberg
Resumen:
Enclaves are lherzolites with varying grades of metasomatism (Montenegro et al., 2016). They are composed of different proportions of pyroxene with exsolutions, olivine with deformation and Fe-Ti-Cr spinel (Al poor), clinopyroxene-spinel simplectic intergrowths and spinel with plagioclase rims. Mineralogical studies reveal a minimum P for the xenoliths sourcebetween 16 and 18 kbar, estimated depth of depth 55- 60 km and 1000 °C. Olivine and clinopyroxene are hosts for different types of inclusions (glass, glass+CO2 and CO2), which are unevenly distributed. According to the CO2 density of pyroxene inclusions (for the estimated T) the capture depth would be 36 km. The CO2 density of inclusions in olivine indicatesthat the carbon fluid in olivine was trapped at a depth of 11 km. These CO2 density variations are attributed to modification and re-equilibration of the primary composition during the ascent.