Skip to Main Content
Skip Nav Destination
GEOREF RECORD

The evolution of the footwall to the Ronda subcontinental mantle peridotites; insights from the Nieves Unit (western Betic Cordillera)

Stefano Mazzoli, A. Martin-Algarra, S. M. Reddy, V. Lopez Sanchez-Vizcaino, L. Fedele and A. Noviello
The evolution of the footwall to the Ronda subcontinental mantle peridotites; insights from the Nieves Unit (western Betic Cordillera)
Journal of the Geological Society of London (May 2013) 170 (3): 385-402

Abstract

Strongly heterogeneous deformation and extreme metamorphic gradients characterize the dominantly carbonate Nieves Unit in the footwall to the Ronda mantle extrusion wedge in the western Betic Cordillera. A well-developed foliation and mineral lineation, together with isoclinal intrafolial folds, occur in silicate-bearing, calcite or dolomite marbles within a c. 1.5 km thick metamorphic aureole underlying the peridotites. For the inferred maximum pressure of 300 MPa, petrological investigations allow us to define temperature ranges for the main zones of the metamorphic aureole: >510 degrees C (probably c. 700 degrees C) for the forsterite zone; 510-430 degrees C for the diopside zone; 430-360 degrees C for the tremolite zone; 360-330 degrees C for the phlogopite zone. Field structural analysis integrated with petrological, microstructural and electron backscatter diffraction textural data document large finite strains consistent with general shear within the metamorphic aureole, associated with NW-directed thrusting of the peridotites. On the other hand, post-kinematic silicate growth suggests that heat diffusion from the high-temperature peridotites continued after the final emplacement of the Ronda mantle extrusion wedge, leading to final zoning of the metamorphic aureole and to local partial annealing of calcite marble textures, particularly in the highest-temperature zone of the thermally softened footwall carbonates. Following substantial cooling, renewed crustal shortening affected the whole Nieves Unit, resulting in widespread development of NE-SW-trending meso-scale folds.


ISSN: 0016-7649
EISSN: 2041-479X
Coden: JGSLAS
Serial Title: Journal of the Geological Society of London
Serial Volume: 170
Serial Issue: 3
Title: The evolution of the footwall to the Ronda subcontinental mantle peridotites; insights from the Nieves Unit (western Betic Cordillera)
Affiliation: University of Naples Federico II, Department of Earth Sciences, Naples, Italy
Pages: 385-402
Published: 201305
Text Language: English
Publisher: Geological Society of London, London, United Kingdom
References: 76
Accession Number: 2013-047807
Categories: Structural geologyIgneous and metamorphic petrology
Document Type: Serial
Bibliographic Level: Analytic
Illustration Description: illus. incl. sects., 2 tables, geol. sketch maps
N36°37'00" - N36°40'00", W05°07'00" - W05°01'60"
Secondary Affiliation: Universidad de Granada, ESP, SpainCurtin University of Technology, AUS, AustraliaUniversidad de Jaen, ESP, Spain
Country of Publication: United Kingdom
Secondary Affiliation: GeoRef, Copyright 2017, American Geosciences Institute. Reference includes data from GeoScienceWorld, Alexandria, VA, United States. Reference includes data from The Geological Society, London, London, United Kingdom
Update Code: 201330
Close Modal

or Create an Account

Close Modal
Close Modal