Premium
The nature and distribution of fluids during amphibolite facies metamorphism, Naxos (Greece)
Author(s) -
BUICK I. S.,
HOLLAND T. J. B.
Publication year - 1991
Publication title -
journal of metamorphic geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.639
H-Index - 114
eISSN - 1525-1314
pISSN - 0263-4929
DOI - 10.1111/j.1525-1314.1991.tb00525.x
Subject(s) - metamorphism , geology , metamorphic rock , metamorphic facies , inclusion (mineral) , fluid inclusions , granulite , geochemistry , facies , petrology , mineralogy , geomorphology , hydrothermal circulation , paleontology , structural basin
On the basis of fluid inclusion evidence, pervasive influx of deep‐seated CO 2 ‐rich fluids has been invoked to account for mid‐ to upper amphibolite facies (M2 B ) metamorphism on the island of Naxos (Cyclades, Greece). In this paper, mineral devolatilization and melt equilibria are used to constrain the composition of both syn‐ and post‐peak‐M2 B fluids in the deepest exposed levels of the metamorphic complex. The results indicate that peak‐M2 B fluids were spatially and compositionally heterogeneous throughout the high‐grade core of the complex, whereas post‐peak‐M2 B fluids were generally water‐rich. The observed heterogeneities in syn‐M2 B fluid composition are inconsistent with pervasive CO 2 ‐flushing models invoked by previous workers on the basis of fluid inclusion evidence. It is likely that few CO 2 ‐rich fluid inclusions on Naxos preserve fluids trapped under peak metamorphic conditions. It is suggested that many of these inclusions have behaved as chemically open systems during the intense deformation that accompanied the uplift of the metamorphic complex. A similar process may explain the occurrence of some CO 2 ‐rich fluid inclusions in granulite facies rocks.