416
Views
8
CrossRef citations to date
0
Altmetric
Articles

Multiscale, multiphysics geomechanics for geodynamics applied to buckling instabilities in the middle of the Australian craton

, , , , , & show all
Pages 3055-3077 | Received 03 Nov 2014, Accepted 04 May 2015, Published online: 17 Aug 2015
 

Abstract

We propose a new multi-physics, multi-scale Integrated Computational Materials Engineering framework for ‘predictive’ geodynamic simulations. A first multiscale application is presented that allows linking our existing advanced material characterization methods from nanoscale through laboratory-, field and geodynamic scales into a new rock simulation framework. The outcome of our example simulation is that the diachronous Australian intraplate orogenic events are found to be caused by one and the same process. This is the non-linear progression of a fundamental buckling instability of the Australian intraplate lithosphere subject to long-term compressive forces. We identify four major stages of the instability: (1) a long wavelength elasto-visco-plastic flexure of the lithosphere without localized failure (first 50 Myrs of loading); (2) an incipient thrust on the central hinge of the model (50–90 Myrs); (3) followed by a secondary and tertiary thrust (90–100 Myrs) 200 km away to either side of the central thrust; (4) a progression of subsidiary thrusts advancing towards the central thrust ( Myrs). The model is corroborated by multiscale observations which are: nano–micro CT analysis of deformed samples in the central thrust giving evidence of cavitation and creep fractures in the thrust; mm–cm size veins of melts (pseudotachylite) that are evidence of intermittent shear heating events in the thrust; and 1–10 km width of the thrust – known as the mylonitic Redbank shear zone – corresponding to the width of the steady state solution, where shear heating on the thrust exactly balances heat diffusion.

Notes

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Australian Research Council [ARC Discovery grant number DP140103015].

Reprints and Corporate Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

To request a reprint or corporate permissions for this article, please click on the relevant link below:

Academic Permissions

Please note: Selecting permissions does not provide access to the full text of the article, please see our help page How do I view content?

Obtain permissions instantly via Rightslink by clicking on the button below:

If you are unable to obtain permissions via Rightslink, please complete and submit this Permissions form. For more information, please visit our Permissions help page.