Stress release in exhumed intermediate and deep earthquakes determined from ultramafic pseudotachylyte

Details

Serval ID
serval:BIB_8DF0923F7E2C
Type
Article: article from journal or magazin.
Collection
Publications
Title
Stress release in exhumed intermediate and deep earthquakes determined from ultramafic pseudotachylyte
Journal
Geology
Author(s)
Andersen T.B., Mair K., Austrheim H., Podladchikov Y.Y., Vrijmoed J.C.
ISSN-L
0091-7613
Publication state
Published
Issued date
2008
Peer-reviewed
Oui
Volume
36
Pages
995-998
Language
english
Abstract
Stresses released by coseismic faults during subduction toward
lawsonite-eclogite facies conditions in the Alpine subduction complex of
Corsica can be estimated based on the energy required to form
pseudotachylyte fault veins where shear strain can be measured.
Congruent peridotite melting at ambient conditions of 1.5 GPa and 470
degrees C requires a temperature increase of 1280 degrees C to 1750
degrees C. We assume that more than 95% of the work is converted to
heat during faulting, hence that the stress drop is nearly proportional
to the amount of melting and inversely proportional to shear strain.
Minimum estimates or released stress are typically greater than 220 MPa
and as high as 580 MPa. The abundance of pseudotachylyte on small faults
in the studied peridotite suggests that melting is very common on
intermediate and deep earthquakes and that shear beating is important
for seismic faulting at depth.
Create date
09/10/2012 20:50
Last modification date
20/08/2019 15:51
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