Cold subduction zone in northern Calabria (Italy) revealed by lawsonite–clinopyroxene blueschists
Lawsonite blueschists are important markers of cold subduction zones, subjected to intense fluid circulation. This is because lawsonite preservation in exhumed blueschists and eclogites is typically linked to cold exhumation paths, accompanied by hydration. In the Catena Costiera (Calabria, southern...
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Online Access: | https://hdl.handle.net/11563/142623 https://doi.org/10.1111/jmg.12528 https://onlinelibrary.wiley.com/doi/abs/10.1111/jmg.12528 |
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ftunivbasilicata:oai:iris.unibas.it:11563/142623 2024-04-21T08:12:38+00:00 Cold subduction zone in northern Calabria (Italy) revealed by lawsonite–clinopyroxene blueschists Fabrizio Tursi Caterina Bianco Andrea Brogi Alfredo Caggianelli Giacomo Prosser Giovanni Ruggieri Eleonora Braschi Tursi, Fabrizio Bianco, Caterina Brogi, Andrea Caggianelli, Alfredo Prosser, Giacomo Ruggieri, Giovanni Braschi, Eleonora 2020 https://hdl.handle.net/11563/142623 https://doi.org/10.1111/jmg.12528 https://onlinelibrary.wiley.com/doi/abs/10.1111/jmg.12528 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000541173200001 volume:38 issue:5 firstpage:451 lastpage:469 numberofpages:19 journal:JOURNAL OF METAMORPHIC GEOLOGY https://hdl.handle.net/11563/142623 doi:10.1111/jmg.12528 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85082967556 https://onlinelibrary.wiley.com/doi/abs/10.1111/jmg.12528 HP–LT metamorphism lawsonite–clinopyroxene blueschists Northern Calabria shear zones subduction info:eu-repo/semantics/article 2020 ftunivbasilicata https://doi.org/10.1111/jmg.12528 2024-03-28T01:14:48Z Lawsonite blueschists are important markers of cold subduction zones, subjected to intense fluid circulation. This is because lawsonite preservation in exhumed blueschists and eclogites is typically linked to cold exhumation paths, accompanied by hydration. In the Catena Costiera (Calabria, southern Italy), lawsonite–clinopyroxene blueschists of the Diamante–Terranova Unit, affected by ductile shearing and retrogression, are exposed. Blueschists contain zoned clinopyroxene crystals, showing core–rim compositional variation from diopside to omphacite and hosting primary inclusions of lawsonite and titanite. Thermodynamic modelling of phase equilibria in the NCKFMASHTO system revealed peak metamorphic conditions of 2.0–2.1 GPa and 475–490°C for the Alpine subduction in Calabria. The subsequent post‐peak metamorphic evolution mainly proceeded along a decompression and cooling path up to ~1.1 GPa and ~380°C. The final exhumation stages are recorded in the sheared blueschists where a mylonitic to ultramylonitic foliation developed at ~0.7 GPa and 290–315°C. Therefore, the P–T evolution of the Diamante–Terranova blueschists mostly occurred in the stability field of lawsonite, sustained by H2O‐saturated conditions during the exhumation path. The results of this study indicate that the blueschists underwent peak metamorphic conditions higher than previously thought, reaching a maximum depth of ~70 km under a very cold geothermal gradient (~6.6°C/km), during the Eocene subduction of the Ligurian Tethys oceanic crust in Calabria. Article in Journal/Newspaper Terranova Università degli Studi della Basilicata: CINECA IRIS Journal of Metamorphic Geology 38 5 451 469 |
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Open Polar |
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Università degli Studi della Basilicata: CINECA IRIS |
op_collection_id |
ftunivbasilicata |
language |
English |
topic |
HP–LT metamorphism lawsonite–clinopyroxene blueschists Northern Calabria shear zones subduction |
spellingShingle |
HP–LT metamorphism lawsonite–clinopyroxene blueschists Northern Calabria shear zones subduction Fabrizio Tursi Caterina Bianco Andrea Brogi Alfredo Caggianelli Giacomo Prosser Giovanni Ruggieri Eleonora Braschi Cold subduction zone in northern Calabria (Italy) revealed by lawsonite–clinopyroxene blueschists |
topic_facet |
HP–LT metamorphism lawsonite–clinopyroxene blueschists Northern Calabria shear zones subduction |
description |
Lawsonite blueschists are important markers of cold subduction zones, subjected to intense fluid circulation. This is because lawsonite preservation in exhumed blueschists and eclogites is typically linked to cold exhumation paths, accompanied by hydration. In the Catena Costiera (Calabria, southern Italy), lawsonite–clinopyroxene blueschists of the Diamante–Terranova Unit, affected by ductile shearing and retrogression, are exposed. Blueschists contain zoned clinopyroxene crystals, showing core–rim compositional variation from diopside to omphacite and hosting primary inclusions of lawsonite and titanite. Thermodynamic modelling of phase equilibria in the NCKFMASHTO system revealed peak metamorphic conditions of 2.0–2.1 GPa and 475–490°C for the Alpine subduction in Calabria. The subsequent post‐peak metamorphic evolution mainly proceeded along a decompression and cooling path up to ~1.1 GPa and ~380°C. The final exhumation stages are recorded in the sheared blueschists where a mylonitic to ultramylonitic foliation developed at ~0.7 GPa and 290–315°C. Therefore, the P–T evolution of the Diamante–Terranova blueschists mostly occurred in the stability field of lawsonite, sustained by H2O‐saturated conditions during the exhumation path. The results of this study indicate that the blueschists underwent peak metamorphic conditions higher than previously thought, reaching a maximum depth of ~70 km under a very cold geothermal gradient (~6.6°C/km), during the Eocene subduction of the Ligurian Tethys oceanic crust in Calabria. |
author2 |
Tursi, Fabrizio Bianco, Caterina Brogi, Andrea Caggianelli, Alfredo Prosser, Giacomo Ruggieri, Giovanni Braschi, Eleonora |
format |
Article in Journal/Newspaper |
author |
Fabrizio Tursi Caterina Bianco Andrea Brogi Alfredo Caggianelli Giacomo Prosser Giovanni Ruggieri Eleonora Braschi |
author_facet |
Fabrizio Tursi Caterina Bianco Andrea Brogi Alfredo Caggianelli Giacomo Prosser Giovanni Ruggieri Eleonora Braschi |
author_sort |
Fabrizio Tursi |
title |
Cold subduction zone in northern Calabria (Italy) revealed by lawsonite–clinopyroxene blueschists |
title_short |
Cold subduction zone in northern Calabria (Italy) revealed by lawsonite–clinopyroxene blueschists |
title_full |
Cold subduction zone in northern Calabria (Italy) revealed by lawsonite–clinopyroxene blueschists |
title_fullStr |
Cold subduction zone in northern Calabria (Italy) revealed by lawsonite–clinopyroxene blueschists |
title_full_unstemmed |
Cold subduction zone in northern Calabria (Italy) revealed by lawsonite–clinopyroxene blueschists |
title_sort |
cold subduction zone in northern calabria (italy) revealed by lawsonite–clinopyroxene blueschists |
publishDate |
2020 |
url |
https://hdl.handle.net/11563/142623 https://doi.org/10.1111/jmg.12528 https://onlinelibrary.wiley.com/doi/abs/10.1111/jmg.12528 |
genre |
Terranova |
genre_facet |
Terranova |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000541173200001 volume:38 issue:5 firstpage:451 lastpage:469 numberofpages:19 journal:JOURNAL OF METAMORPHIC GEOLOGY https://hdl.handle.net/11563/142623 doi:10.1111/jmg.12528 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-85082967556 https://onlinelibrary.wiley.com/doi/abs/10.1111/jmg.12528 |
op_doi |
https://doi.org/10.1111/jmg.12528 |
container_title |
Journal of Metamorphic Geology |
container_volume |
38 |
container_issue |
5 |
container_start_page |
451 |
op_container_end_page |
469 |
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