Rock fluidization during peak-ring formation of large impact structures

Riller, U. et al. (2018) Rock fluidization during peak-ring formation of large impact structures. Nature, 562(7728), pp. 511-518. (doi:10.1038/s41586-018-0607-z) (PMID:30356184)

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Abstract

Large meteorite impact structures on the terrestrial bodies of the Solar System contain pronounced topographic rings, which emerged from uplifted target (crustal) rocks within minutes of impact. To flow rapidly over large distances, these target rocks must have weakened drastically, but they subsequently regained sufficient strength to build and sustain topographic rings. The mechanisms of rock deformation that accomplish such extreme change in mechanical behaviour during cratering are largely unknown and have been debated for decades. Recent drilling of the approximately 200-km-diameter Chicxulub impact structure in Mexico has produced a record of brittle and viscous deformation within its peak-ring rocks. Here we show how catastrophic rock weakening upon impact is followed by an increase in rock strength that culminated in the formation of the peak ring during cratering. The observations point to quasi-continuous rock flow and hence acoustic fluidization as the dominant physical process controlling initial cratering, followed by increasingly localized faulting.

Item Type:Articles
Additional Information:Pickersgill, A.E. is a member of the IODP-ICDP Expedition 364 Science Party.
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Pickersgill, Dr Annemarie
Authors: Riller, U., Poelchau, M. H., Rae, A. S. P., Schulte, F. M., Collins, G. S., Melosh, H. J., Grieve, R. A. F., Morgan, J. V., Gulick, S. P. S., Lofi, J., Diaw, A., McCall, N., Kring, D. A., and IODP–ICDP Expedition 364 Science Party,
College/School:College of Science and Engineering > School of Geographical and Earth Sciences
Journal Name:Nature
Publisher:Nature Research
ISSN:0028-0836
ISSN (Online):1476-4687
Published Online:24 October 2018
Copyright Holders:Copyright © 2018 Springer Nature Limited
First Published:First published in Nature 562(7728): 511-518
Publisher Policy:Reproduced in accordance with the publisher copyright policy

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