The evolution of the footwall to the Ronda subcontinental mantle peridotites: insights from the Nieves Unit (western Betic Cordillera)
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, occ...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
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Geological Society Publishing House
2013
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| Online Access: | http://hdl.handle.net/20.500.11937/25240 |
| _version_ | 1848751653435473920 |
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| author | Mazzoli, S. Martín-Algarra, A. Reddy, Steven López Sánchez-Vizcaíno, V. Fedele, L. Noviello, A. |
| author_facet | Mazzoli, S. Martín-Algarra, A. Reddy, Steven López Sánchez-Vizcaíno, V. Fedele, L. Noviello, A. |
| author_sort | Mazzoli, S. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | 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 °C (probably c. 700 °C) for the forsterite zone; 510–430 °C for the diopside zone; 430–360 °C for the tremolite zone; 360–330 °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. |
| first_indexed | 2025-11-14T07:56:09Z |
| format | Journal Article |
| id | curtin-20.500.11937-25240 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T07:56:09Z |
| publishDate | 2013 |
| publisher | Geological Society Publishing House |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-252402017-09-13T15:21:50Z The evolution of the footwall to the Ronda subcontinental mantle peridotites: insights from the Nieves Unit (western Betic Cordillera) Mazzoli, S. Martín-Algarra, A. Reddy, Steven López Sánchez-Vizcaíno, V. Fedele, L. Noviello, A. EBSD mantle peridotite deformation carbonates metamorphism 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 °C (probably c. 700 °C) for the forsterite zone; 510–430 °C for the diopside zone; 430–360 °C for the tremolite zone; 360–330 °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. 2013 Journal Article http://hdl.handle.net/20.500.11937/25240 10.1144/jgs2012-105 Geological Society Publishing House fulltext |
| spellingShingle | EBSD mantle peridotite deformation carbonates metamorphism Mazzoli, S. Martín-Algarra, A. Reddy, Steven López Sánchez-Vizcaíno, V. Fedele, L. Noviello, A. The evolution of the footwall to the Ronda subcontinental mantle peridotites: insights from the Nieves Unit (western Betic Cordillera) |
| title | The evolution of the footwall to the Ronda subcontinental mantle peridotites: insights from the Nieves Unit (western Betic Cordillera) |
| title_full | The evolution of the footwall to the Ronda subcontinental mantle peridotites: insights from the Nieves Unit (western Betic Cordillera) |
| title_fullStr | The evolution of the footwall to the Ronda subcontinental mantle peridotites: insights from the Nieves Unit (western Betic Cordillera) |
| title_full_unstemmed | The evolution of the footwall to the Ronda subcontinental mantle peridotites: insights from the Nieves Unit (western Betic Cordillera) |
| title_short | The evolution of the footwall to the Ronda subcontinental mantle peridotites: insights from the Nieves Unit (western Betic Cordillera) |
| title_sort | evolution of the footwall to the ronda subcontinental mantle peridotites: insights from the nieves unit (western betic cordillera) |
| topic | EBSD mantle peridotite deformation carbonates metamorphism |
| url | http://hdl.handle.net/20.500.11937/25240 |