TY - JOUR
T1 - Recrystallization textures in zircon generated by ocean-floor and eclogite-facies metamorphism
T2 - A cathodoluminescence and U-Pb shrimp study, with constraints from REE elements
AU - Puga, Encarnación
AU - Fanning, C. Mark
AU - Nieto, José Miguel
AU - Díaz de Federico, Antonio
PY - 2005/2
Y1 - 2005/2
N2 - Eclogites formed during the Eo-alpine metamorphic event are common within the ophiolitic unit of the Mulhacén complex, which forms part of the Betic Cordillera in southeastern Spain. A detailed study with cathodoluminescence (CL) images of zircon from these eclogites has revealed three types of domains, confirmed by some differences in their REE patterns and ages. There are a) igneous domains, with oscillatory zoning, yielding an Early to Middle Jurassic age, dating the crystallization of the basic protolith, and b) two different types of recrystallized metamorphic domains, one with grey homogeneous CL images, mainly clustering around the Late Jurassic, and the other with bright clouded CL images, ranging down to a Late Cretaceous to Paleocene age. These two types of recrystallized areas in the zircon are interpreted as having formed during the ocean-floor and the Eo-alpine metamorphism, in eclogite-facies conditions, respectively. We contend that processes of metamorphic recrystallization, which are more pervasive in the internal part of the zircon crystals than at their edge, was facilitated by oceanic fluids that circulated through them and were located in their vesicles, forming fluid inclusions.
AB - Eclogites formed during the Eo-alpine metamorphic event are common within the ophiolitic unit of the Mulhacén complex, which forms part of the Betic Cordillera in southeastern Spain. A detailed study with cathodoluminescence (CL) images of zircon from these eclogites has revealed three types of domains, confirmed by some differences in their REE patterns and ages. There are a) igneous domains, with oscillatory zoning, yielding an Early to Middle Jurassic age, dating the crystallization of the basic protolith, and b) two different types of recrystallized metamorphic domains, one with grey homogeneous CL images, mainly clustering around the Late Jurassic, and the other with bright clouded CL images, ranging down to a Late Cretaceous to Paleocene age. These two types of recrystallized areas in the zircon are interpreted as having formed during the ocean-floor and the Eo-alpine metamorphism, in eclogite-facies conditions, respectively. We contend that processes of metamorphic recrystallization, which are more pervasive in the internal part of the zircon crystals than at their edge, was facilitated by oceanic fluids that circulated through them and were located in their vesicles, forming fluid inclusions.
KW - Alpine metamorphism
KW - Betic Cordillera
KW - Eclogites
KW - Ocean-floor metamorphism
KW - Ophiolites
KW - REE analyses
KW - Recrystallization textures
KW - Spain
KW - U-Pb SHRIMP dating
KW - Zircon
UR - http://www.scopus.com/inward/record.url?scp=18944382020&partnerID=8YFLogxK
U2 - 10.2113/gscanmin.43.1.183
DO - 10.2113/gscanmin.43.1.183
M3 - Article
SN - 0008-4476
VL - 43
SP - 183
EP - 202
JO - Canadian Mineralogist
JF - Canadian Mineralogist
IS - 1
ER -