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Low‐thermal‐gradient Hercynian metamorphism in the eastern Pyrenees
Author(s) -
AYORA C.,
LlESA M.,
DELGADO J.
Publication year - 1993
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.1525-1314.1993.tb00130.x
Subject(s) - metamorphism , geology , metamorphic rock , massif , geochemistry , arsenopyrite , orogeny , chlorite , quartz , petrology , geomorphology , paleontology , structural basin , chalcopyrite , chemistry , organic chemistry , copper
Fluids with compositions in the system CO 2 ‐H 2 O‐NaCl were trapped in quartz veins enclosed in low‐grade metamorphic rocks (chlorite zone) on the southern flank of the Canigó Massif, eastern Pyrenees. The veins, which also contain arsenopyrite crystals, were formed contemporaneously with the main Hercynian foliation and metamorphism. Volumetric properties of the fluid and the results of arsenopyrite geothermometry suggest P‐T trapping conditions of 4.6–6 kbar and 450–530° C. This implies that an episode of metamorphism with an average geothermal gradient of 25° C km −1 occurred during the main deformation event. This episode preceded the low‐ P /high‐ T metamorphism described around domes and to date considered as characteristic of the Hercynian orogeny in the Pyrenees.