Fossil intermediate-depth earthquakes in subducting slabs linked to differential stress release

Journal article
(Original article)


Publication Details

Author(s): Scambelluri M, Pennacchioni G, Gilio M, Bestmann M, Plumper O, Nestola F
Journal: Nature Geoscience
Publisher: NATURE PUBLISHING GROUP
Publication year: 2017
Volume: 10
Journal issue: 12
Pages range: 960-+
ISSN: 1752-0894


Abstract

The cause of intermediate-depth (50-300 km) seismicity in subduction zones is uncertain. It is typically attributed either to rock embrittlement associated with fluid pressurization, or to thermal runaway instabilities. Here we document glassy pseudotachylyte fault rocks-the products of frictional melting during coseismic faulting-in the Lanzo Massif ophiolite in the Italian Western Alps. These pseudotachylytes formed at subduction-zone depths of 60-70 km in poorly hydrated to dry oceanic gabbro and mantle peridotite. This rock suite is a fossil analogue to an oceanic lithospheric mantle that undergoes present-day subduction. The pseudotachylytes locally preserve high-pressure minerals that indicate an intermediate-depth seismic environment. These pseudotachylytes are important because they are hosted in a near-anhydrous lithosphere free of coeval ductile deformation, which excludes an origin by dehydration embrittlement or thermal runaway processes. Instead, our observations indicate that seismicity in cold subducting slabs can be explained by the release of differential stresses accumulated in strong dry metastable rocks.


FAU Authors / FAU Editors

Bestmann, Michel Dr.
Professur für Geologie unter besonderer Berücksichtigung der Strukturgeologie [Tektonik] und Photogeologie


External institutions
Universiteit Utrecht (UU) / Utrecht University
University of Genova / Università degli Studi di Genova
University of Padova / Universita degli Studi di Padova
University of Padua


How to cite

APA:
Scambelluri, M., Pennacchioni, G., Gilio, M., Bestmann, M., Plumper, O., & Nestola, F. (2017). Fossil intermediate-depth earthquakes in subducting slabs linked to differential stress release. Nature Geoscience, 10(12), 960-+. https://dx.doi.org/10.1038/s41561-017-0010-7

MLA:
Scambelluri, Marco, et al. "Fossil intermediate-depth earthquakes in subducting slabs linked to differential stress release." Nature Geoscience 10.12 (2017): 960-+.

BibTeX: 

Last updated on 2018-22-07 at 23:11