Quartz rheology and short-time-scale crustal instabilities

Klaus Regenauer-Lieb, David A. Yuen

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

We present numerical results of thermal-mechanical feedback in crustal quartz rheology and contrast this behavior to the vastly different character of an olivine mantle. In the numerical experiments quartz is found to have a very strong tendency for short-time-scale instabilities, while our numerical experiments show that olivine has a decisive tendency for a stable thermally lubricated slip. At the same time, olivine can also go through a transitional period of creep bursts, which are physically caused by multiple interacting ductile faults at various length and time scales which collocate quickly into a major shear zone. Since olivine has this strong propensity to self organize in a large apparently stable fault system, it lacks the dynamics of interacting ductile faults evident in other minerals. Quartz behaves totally different and keeps its jerky slip behavior for prolonged deformation. An example is shown here in which a 30 × 50 km piece of a wet quarzitic crust is extended for about 2 Ma. The associated total displacement field clearly shows the unstable slipping events, which have a characteristic time frame of one to several years, In contrast, olivine is very stable and has a much longer time scale for thermal instability of 100 kyrs.

Original languageEnglish (US)
Pages (from-to)1915-1932
Number of pages18
JournalPure and Applied Geophysics
Volume163
Issue number9
DOIs
StatePublished - Sep 2006

Bibliographical note

Funding Information:
We would like to acknowledge reviews of Matt Davis and Klaus Gottschalk. This work was carried out at CSIRO Exploration and Mining Perth and continued at the Johannes Gutenberg-Universität Mainz. The use of computational facilities at the ETH Zürich and the Minnesota Supercomputer Institute at the University of Minneapolis are gratefully acknowledged. We appreciate discussions with Boris Kaus and Satoru Honda. We also received support from CSEDI, Math-GEO and ITR grants from the National Science Foundation and the predictive mineral discovery Cooperative Research Centre pmd*CRC.

Copyright:
Copyright 2011 Elsevier B.V., All rights reserved.

Keywords

  • Instability
  • Quartz
  • Rheology
  • Slow earthquake
  • Thermal-mechanical mode

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