Genesis of corrugated fault surfaces by strain localization recorded at oceanic detachments
| العنوان: | Genesis of corrugated fault surfaces by strain localization recorded at oceanic detachments |
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| المؤلفون: | Ross Parnell-Turner, Sven Petersen, Jean-Arthur Olive, Javier Escartín, D. K. Smith |
| المساهمون: | Woods Hole Oceanographic Institution (WHOI), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Institute for Cell and Molecular Biosciences, Newcastle University [Newcastle], Helmholtz Centre for Ocean Research [Kiel] (GEOMAR), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), GEOMAR - Helmholtz Centre for Ocean Research [Kiel] (GEOMAR) |
| المصدر: | Earth and Planetary Science Letters Earth and Planetary Science Letters, Elsevier, 2018, 498, pp.116-128. ⟨10.1016/j.epsl.2018.06.034⟩ Earth and Planetary Science Letters, 498 . pp. 116-128. |
| بيانات النشر: | HAL CCSD, 2018. |
| سنة النشر: | 2018 |
| مصطلحات موضوعية: | 010504 meteorology & atmospheric sciences, mid-ocean ridge, Slip (materials science), Fault (geology), 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), oceanic detachment faulting, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), Bathymetry, 14. Life underwater, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [SDU.STU.TE]Sciences of the Universe [physics]/Earth Sciences/Tectonics, geography, geography.geographical_feature_category, Subduction, corrugations, Mid-ocean ridge, Seafloor spreading, Tectonics, Geophysics, [SDU]Sciences of the Universe [physics], Space and Planetary Science, Seismology, Geology |
| الوصف: | International audience; Seafloor spreading at slow and ultraslow rates is often taken up by extension on large-offset faults called detachments, which exhume lower crustal and mantle rocks, and in some cases make up domed oceanic core complexes. The exposed footwall may reveal a characteristic pattern of spreading-parallel corrugations, the largest of which are clearly visible in multibeam bathymetric data, and whose nature and origin have been the subject of controversy. In order to tackle this debate, we use available near-bottom bathymetric surveys recently acquired with autonomous deep-sea vehicles over five corrugated detachments along the Mid-Atlantic Ridge. With a spatial resolution of 2 m, these data allow us to compare the geometry of corrugations on oceanic detachments that are characterized by differing fault zone lithologies, and accommodate varying amounts of slip. The fault surfaces host corrugations with wavelengths of 10–250 m, while individual corrugations are finite in length, typically 100–500 m. Power spectra of profiles calculated across the corrugated fault surfaces reveal a common level of roughness, and indicate that the fault surfaces are not fractal. Since systematic variation in roughness with fault offset is not evident, we propose that portions of the exposed footwalls analyzed here record constant brittle strain. We assess three competing hypotheses for corrugation formation and find that the continuous casting and varying depth to brittle–ductile transition models cannot explain the observed corrugation geometry nor available geological observations. We suggest a model involving brittle strain localization on a network of linked fractures within a zone of finite thickness is a better explanation for the observations. This model explains corrugations on oceanic detachment faults exposed at the seafloor and on normal faults in the continents, and is consistent with recently imaged corrugations on a subduction zone megathrust. Hence fracture linkage and coalescence may give rise to corrugated fault zones, regardless of earlier deformation history and tectonic setting. |
| وصف الملف: | text |
| اللغة: | English |
| تدمد: | 0012-821X |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::640abd5014a9aa70129748dca763ff6d https://hal.archives-ouvertes.fr/hal-02330321/document |
| حقوق: | OPEN |
| رقم الأكسشن: | edsair.doi.dedup.....640abd5014a9aa70129748dca763ff6d |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 0012821X |
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