Publication:
Exhumation of ultra-high pressure (UHP) rocks modulated by rifted margin-subduction feedback: implications for their preservation in old collisional orogens

cris.virtual.author-orcid0000-0002-7425-7904
cris.virtual.author-orcid0000-0001-8360-3592
cris.virtual.author-orcid0000-0001-8303-0771
cris.virtualsource.author-orcid96ba97b4-0a95-40c6-bf88-128b53e019d0
cris.virtualsource.author-orcid3a4d5149-308a-4ae9-a77b-7c0be7d4d1b1
cris.virtualsource.author-orcid49b1b6d0-ad93-4744-ac4a-b994caa4f537
cris.virtualsource.author-orcid7e421314-0d5f-49d7-8385-bfe4b093cd38
datacite.rightsrestricted
dc.contributor.authorGanade De Araujo, Carlos Eduardo
dc.contributor.authorRiel, Nicolas
dc.contributor.authorManatschal, Gianreto
dc.contributor.authorTesser, Lucas R.
dc.contributor.authorRubatto, Daniela
dc.contributor.authorHermann, Jörg
dc.contributor.authorWeinberg, Roberto F.
dc.contributor.authorLanari, Pierre
dc.contributor.authorKaus, Boris J. P.
dc.date.accessioned2024-10-26T18:40:33Z
dc.date.available2024-10-26T18:40:33Z
dc.date.issued2024-10-01
dc.description.abstractIn continental subduction, rifted margins can be carried to mantle depths (> 90 km) where ultra-high pressure (UHP) metamorphism above coesite stability is attained. Although different exhumation mechanisms for UHP rocks have been discussed, none of them integrate the recent understanding of rifted continental margins. Here, we perform high-resolution thermomechanical numerical experiments to demonstrate that segments of magma-poor rifted margins that reach UHP conditions can efficiently exhume back to shallower levels, while segments of magma-rich rifted margins cannot. This is because the thick layer of rocks with a basaltic composition in magma-rich margins becomes negatively buoyant during metamorphism, preventing their exhumation. This new concept might be pivotal for explaining why exhumed UHP rocks, a key feature of modern-style continental orogens, only appeared and became common late in Earth's history. We suggest that higher mantle potential temperatures and fertility in Earth's early history favored magma-rich rifted margins, making exhumation of UHP crust inefficient. Conditions for magma-poor rifted margins may have arisen during Earth's middle age (1.5–0.8 Ga) due to a colder, more refractory mantle that limited melting and magmatism. We argue that at the end of Neoproterozoic, these colder and positively buoyant magma-poor rifted margins were then subducted and efficiently exhumed to form the large collisional orogens of Gondwana where Earth's oldest coesite-bearing UHP rocks have been unequivocally found. Since then, UHP rocks have become a key and ubiquitous feature of continental orogens.
dc.description.sponsorshipInstitute of Geological Sciences (GEO) - Metamorphic Geochemistry
dc.description.sponsorshipInstitute of Geological Sciences (GEO) - Petrology
dc.description.sponsorshipInstitute of Geological Sciences (GEO) - Computational Petrology and Geochemistry
dc.description.sponsorshipInstitute of Geological Sciences (GEO)
dc.identifier.doi10.48350/199552
dc.identifier.publisherDOI10.1016/j.epsl.2024.118893
dc.identifier.urihttps://boris-portal.unibe.ch/handle/20.500.12422/179622
dc.language.isoen
dc.publisherElsevier
dc.relation.ispartofEarth and planetary science letters
dc.relation.issn0012-821X
dc.relation.organizationDCD5A442C02AE17DE0405C82790C4DE2
dc.relation.organizationDCD5A442C18FE17DE0405C82790C4DE2
dc.relation.organizationDCD5A442C191E17DE0405C82790C4DE2
dc.subject.ddc500 - Science::550 - Earth sciences & geology
dc.titleExhumation of ultra-high pressure (UHP) rocks modulated by rifted margin-subduction feedback: implications for their preservation in old collisional orogens
dc.typearticle
dspace.entity.typePublication
dspace.file.typetext
oaire.citation.volume643
oairecerif.author.affiliationInstitute of Geological Sciences (GEO)
oairecerif.author.affiliationInstitute of Geological Sciences (GEO) - Metamorphic Geochemistry
oairecerif.author.affiliationInstitute of Geological Sciences (GEO) - Petrology
oairecerif.author.affiliationInstitute of Geological Sciences (GEO) - Computational Petrology and Geochemistry
oairecerif.author.affiliation2Institute of Geological Sciences (GEO)
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unibe.date.licenseChanged2024-08-07 11:45:56
unibe.description.ispublishedpub
unibe.eprints.legacyId199552
unibe.journal.abbrevTitleEARTH PLANET SC LETT
unibe.refereedtrue
unibe.subtype.articlejournal

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