Journal ArticleDOI
Thin crust, ultramafic exposures, and rugged faulting patterns at the Mid-Atlantic Ridge (22°–24°N)
Mathilde Cannat,Catherine Mével,Marcia Maia,Christine Deplus,Cecile Durand,Pascal Gente,Pierre Agrinier,Abdel Belarouchi,Gilles Dubuisson,Eric Humler,Jennifer R. Reynolds +10 more
TLDR
In this paper, the authors find a good correlation between domains of positive residual gravity anomalies (inferred to have a thin crust) and the distribution of ultramafic samples and also find that thin-crust domains have a rugged topography, thought to reflect strong tectonic disruption.Abstract:
Off-axis rock sampling in the lat 22°–24° N region of the Mid-Atlantic Ridge shows that the emplacement of mantle-derived rocks in the sea floor has been a common process there for the past few million years. We find a good correlation between domains of positive residual gravity anomalies (inferred to have a thin crust) and the distribution of ultramafic samples. We also find that thin-crust domains have a rugged topography, thought to reflect strong tectonic disruption. We propose that these thin-crust domains are made of tectonically uplifted ultramafic rocks, with gabbroic intrusions and a thin basaltic cover. We also suggest that strong tectonic disruption may be a direct consequence of the lithological and rheological heterogeneity of these thin-crust domains.read more
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Journal ArticleDOI
Ophiolite genesis and global tectonics: Geochemical and tectonic fingerprinting of ancient oceanic lithosphere
Yildirim Dilek,Harald Furnes +1 more
TL;DR: A review of these ideas as well as a new classification of ophiolites, incorporating the diversity in their structural architecture and geochemical signatures that results from variations in petrological, geochemical, and tectonic processes during formation in different geodynamic settings is presented in this article.
Journal ArticleDOI
Geochemistry of subduction zone serpentinites: A review
TL;DR: A review of the geochemistry of serpentinites, based on the compilation of ~900 geochemical data of abyssal, mantle wedge and exhumed serpentinite after subduction, is presented in this paper.
Journal ArticleDOI
Megamullions and mullion structure defining oceanic metamorphic core complexes on the Mid-Atlantic Ridge
TL;DR: In this article, the authors identified 17 large, domed edifices (megamullions) that have surfaces corrugated by distinctive mullion structure and that are developed within inside-corner tectonic settings at ends of spreading segments.
Journal ArticleDOI
Reevaluating carbon fluxes in subduction zones, what goes down, mostly comes up.
TL;DR: Carbon fluxes in subduction zones can be better constrained by including new estimates of carbon concentration in subducting mantle peridotites, consideration of carbonate solubility in aqueous fluid along subduction geotherms, and diapirism of carbon-bearing metasediments.
Journal ArticleDOI
Corrugated slip surfaces formed at ridge–transform intersections on the Mid-Atlantic Ridge
Johnson R. Cann,Donna K. Blackman,Deborah K. Smith,E. McAllister,B. Janssen,Sidney L. M. Mello,E. Avgerinos,A. R. Pascoe,Javier Escartín +8 more
TL;DR: In this article, the authors present sonar images of two ridge-transform intersections on the Mid-Atlantic Ridge (near 30° N), which show that both active and fossilized inside-corner highs are capped by planar, dipping surfaces marked by corrugations and striations oriented parallel to the plate spreading direction.
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