Early Mylonitization in the Nevado-Filábride Complex (Betic Cordillera) during the High-Pressure Episode: Petrological, Geochemical and Thermobarometric Data
Metadatos
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MDPI
Materia
Compositional maps Garnet thermobarometry Nevado-Filábride complex Phengite SEM Sierra de los Filabres Betic Cordillera
Fecha
2022-12-23Referencia bibliográfica
Santamaría-López, Á... [et al.]. Early Mylonitization in the Nevado-Filábride Complex (Betic Cordillera) during the High-Pressure Episode: Petrological, Geochemical and Thermobarometric Data. Minerals 2023, 13, 24. [https://doi.org/10.3390/min13010024]
Patrocinador
MCIN-AEI PGC2018-094573-B-I00; PID2019-104624RB-I00; Junta de Andalucia PY20_00675; Project FEDER-UJA 2020 1380934; Junta de Andalucia RNM-325 RNM-179Resumen
In the western part of the Sierra de los Filabres area, there are fine-grained metamorphic
rock bands, showing a field aspect simitar to slates, as previously described in the geological literature
of the studied region. They are variable in thickness, from millimeters to tens of meters and appear
intercalated in the schist succession. The geochemical resemblance between both types of rocks
(major, minor and trace elements), determined by a statistical approach and the comparison of
depositional condition indices, points to a similar sedimentary origin of the protolith but different
clay content. Mineral facies and illite “crystallinity” indices in the so-called slates indicate that
they followed the same metamorphic path and reached the same metamorphic grade than schists.
According to compositional zoning detected in micas and garnets present in both lithologies and
the P-T conditions deduced from garnets, the mineral nucleation and growth episode of the main
mineral paragenesis in these fine-grained schists was more remarkable during the high-pressure
event, with a no significant effect of the latter low-pressure–high-temperature episode. In contrast,
the coarse-grained schists developed higher size minerals during the low-pressure–high-temperature
episode. A differential mylonitization process during the metamorphism is proposed to justify the
discrepant field appearance and the contrasting response of both types of metapelitic rocks to the
latter metamorphic event.