Controls on the seafloor exposure of detachment fault surfaces
Highlights • A small fraction of corrugated detachment fault surfaces is eventually exposed at the seafloor. • Seafloor slopes indicate effective friction of ∼0.2 on shallow part of detachments. • Moderate-offset detachment faults may be largely blanketed by hanging wall material. • Seafloor-shaping...
Published in: | Earth and Planetary Science Letters |
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Online Access: | https://oceanrep.geomar.de/id/eprint/44845/ https://oceanrep.geomar.de/id/eprint/44845/1/Olive.pdf https://oceanrep.geomar.de/id/eprint/44845/6/Olive2019.pdf https://doi.org/10.1016/j.epsl.2018.11.001 |
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ftoceanrep:oai:oceanrep.geomar.de:44845 2023-05-15T17:35:01+02:00 Controls on the seafloor exposure of detachment fault surfaces Olive, Jean-Arthur Parnell-Turner, Ross Escartín, Javier Smith, Deborah K. Petersen, Sven 2019-01-15 text https://oceanrep.geomar.de/id/eprint/44845/ https://oceanrep.geomar.de/id/eprint/44845/1/Olive.pdf https://oceanrep.geomar.de/id/eprint/44845/6/Olive2019.pdf https://doi.org/10.1016/j.epsl.2018.11.001 en eng Elsevier https://oceanrep.geomar.de/id/eprint/44845/1/Olive.pdf https://oceanrep.geomar.de/id/eprint/44845/6/Olive2019.pdf Olive, J. A. , Parnell-Turner, R. , Escartín, J. , Smith, D. K. and Petersen, S. (2019) Controls on the seafloor exposure of detachment fault surfaces. Open Access Earth and Planetary Science Letters, 506 . pp. 381-387. DOI 10.1016/j.epsl.2018.11.001 <https://doi.org/10.1016/j.epsl.2018.11.001>. doi:10.1016/j.epsl.2018.11.001 info:eu-repo/semantics/openAccess Article PeerReviewed info:eu-repo/semantics/article 2019 ftoceanrep https://doi.org/10.1016/j.epsl.2018.11.001 2023-04-07T15:42:17Z Highlights • A small fraction of corrugated detachment fault surfaces is eventually exposed at the seafloor. • Seafloor slopes indicate effective friction of ∼0.2 on shallow part of detachments. • Moderate-offset detachment faults may be largely blanketed by hanging wall material. • Seafloor-shaping processes profoundly alter the morphology of oceanic core complexes. Abstract While oceanic detachment faults have been proposed to account for the accretion of ∼40% of new seafloor in the North Atlantic ocean, clear exposures of large-offset, often-corrugated fault surfaces remain scarce and spatially limited. To help resolve this paradox, we examine the conditions under which detachment fault growth may or may not lead to extensive exposure of corrugated fault planes at the seafloor. Using high-resolution bathymetry from four detachment faults at the northern Mid-Atlantic Ridge, we investigate the rafting of hanging wall-derived debris over emerging fault scarps, which can lead to covering shallow-dipping corrugated fault surfaces. We model this process using critical taper theory, and infer low effective friction coefficients (∼0.2) on the shallowest portion of detachment faults. A corollary to this result is that detachments emerging from the seafloor at angles <13° are more likely to become blanketed under an apron of hanging wall material. We generalize these findings as a simple model for the progressive exposure and flexural rotation of detachment footwalls, which accounts for the continued action of seafloor-shaping processes. Our model suggests that many moderate-offset, hidden detachment faults may exist along slow mid-ocean ridges, and do not feature an exposed fault surface. Article in Journal/Newspaper North Atlantic OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Mid-Atlantic Ridge Earth and Planetary Science Letters 506 381 387 |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
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ftoceanrep |
language |
English |
description |
Highlights • A small fraction of corrugated detachment fault surfaces is eventually exposed at the seafloor. • Seafloor slopes indicate effective friction of ∼0.2 on shallow part of detachments. • Moderate-offset detachment faults may be largely blanketed by hanging wall material. • Seafloor-shaping processes profoundly alter the morphology of oceanic core complexes. Abstract While oceanic detachment faults have been proposed to account for the accretion of ∼40% of new seafloor in the North Atlantic ocean, clear exposures of large-offset, often-corrugated fault surfaces remain scarce and spatially limited. To help resolve this paradox, we examine the conditions under which detachment fault growth may or may not lead to extensive exposure of corrugated fault planes at the seafloor. Using high-resolution bathymetry from four detachment faults at the northern Mid-Atlantic Ridge, we investigate the rafting of hanging wall-derived debris over emerging fault scarps, which can lead to covering shallow-dipping corrugated fault surfaces. We model this process using critical taper theory, and infer low effective friction coefficients (∼0.2) on the shallowest portion of detachment faults. A corollary to this result is that detachments emerging from the seafloor at angles <13° are more likely to become blanketed under an apron of hanging wall material. We generalize these findings as a simple model for the progressive exposure and flexural rotation of detachment footwalls, which accounts for the continued action of seafloor-shaping processes. Our model suggests that many moderate-offset, hidden detachment faults may exist along slow mid-ocean ridges, and do not feature an exposed fault surface. |
format |
Article in Journal/Newspaper |
author |
Olive, Jean-Arthur Parnell-Turner, Ross Escartín, Javier Smith, Deborah K. Petersen, Sven |
spellingShingle |
Olive, Jean-Arthur Parnell-Turner, Ross Escartín, Javier Smith, Deborah K. Petersen, Sven Controls on the seafloor exposure of detachment fault surfaces |
author_facet |
Olive, Jean-Arthur Parnell-Turner, Ross Escartín, Javier Smith, Deborah K. Petersen, Sven |
author_sort |
Olive, Jean-Arthur |
title |
Controls on the seafloor exposure of detachment fault surfaces |
title_short |
Controls on the seafloor exposure of detachment fault surfaces |
title_full |
Controls on the seafloor exposure of detachment fault surfaces |
title_fullStr |
Controls on the seafloor exposure of detachment fault surfaces |
title_full_unstemmed |
Controls on the seafloor exposure of detachment fault surfaces |
title_sort |
controls on the seafloor exposure of detachment fault surfaces |
publisher |
Elsevier |
publishDate |
2019 |
url |
https://oceanrep.geomar.de/id/eprint/44845/ https://oceanrep.geomar.de/id/eprint/44845/1/Olive.pdf https://oceanrep.geomar.de/id/eprint/44845/6/Olive2019.pdf https://doi.org/10.1016/j.epsl.2018.11.001 |
geographic |
Mid-Atlantic Ridge |
geographic_facet |
Mid-Atlantic Ridge |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
https://oceanrep.geomar.de/id/eprint/44845/1/Olive.pdf https://oceanrep.geomar.de/id/eprint/44845/6/Olive2019.pdf Olive, J. A. , Parnell-Turner, R. , Escartín, J. , Smith, D. K. and Petersen, S. (2019) Controls on the seafloor exposure of detachment fault surfaces. Open Access Earth and Planetary Science Letters, 506 . pp. 381-387. DOI 10.1016/j.epsl.2018.11.001 <https://doi.org/10.1016/j.epsl.2018.11.001>. doi:10.1016/j.epsl.2018.11.001 |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.epsl.2018.11.001 |
container_title |
Earth and Planetary Science Letters |
container_volume |
506 |
container_start_page |
381 |
op_container_end_page |
387 |
_version_ |
1766134035593035776 |