Linking megathrust earthquakes to brittle deformation in a fossil accretionary complex

Dielforder, Armin; Vollstaedt, Hauke; Vennemann, Torsten; Berger, Alfons; Herwegh, Marco (2015). Linking megathrust earthquakes to brittle deformation in a fossil accretionary complex. Nature communications, 6, p. 7504. Nature Publishing Group 10.1038/ncomms8504

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Seismological data from recent subduction earthquakes suggest that megathrust earthquakes induce transient stress changes in the upper plate that shift accretionary wedges into an unstable state. These stress changes have, however, never been linked to geological structures preserved in fossil accretionary complexes. The importance of coseismically induced wedge failure has therefore remained largely elusive. Here we show that brittle faulting and vein formation in the palaeo-accretionary complex of the European Alps record stress changes generated by subduction-related earthquakes. Early veins formed at shallow levels by bedding-parallel shear during coseismic compression of the outer wedge. In contrast, subsequent vein formation occurred by normal faulting and extensional fracturing at deeper levels in response to coseismic extension of the inner wedge. Our study demonstrates how mineral veins can be used to reveal the dynamics of outer and inner wedges, which respond in opposite ways to megathrust earthquakes by compressional and extensional faulting, respectively.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geological Sciences
08 Faculty of Science > Institute of Geological Sciences > Tectonics

UniBE Contributor:

Dielforder, Armin; Vollstaedt, Hauke; Berger, Alfons and Herwegh, Marco

Subjects:

500 Science > 550 Earth sciences & geology

ISSN:

2041-1723

Publisher:

Nature Publishing Group

Language:

English

Submitter:

Marco Herwegh

Date Deposited:

29 Jun 2015 10:32

Last Modified:

30 Jun 2015 04:01

Publisher DOI:

10.1038/ncomms8504

PubMed ID:

26105966

BORIS DOI:

10.7892/boris.69859

URI:

https://boris.unibe.ch/id/eprint/69859

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