Boom boom pow: shock-facilitated aqueous alteration and evidence for two shock events in the Martian nakhlite meteorites

Daly, L. et al. (2019) Boom boom pow: shock-facilitated aqueous alteration and evidence for two shock events in the Martian nakhlite meteorites. Science Advances, 5(9), eaaw5549. (doi: 10.1126/sciadv.aaw5549)

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Abstract

Nakhlite meteorites are ~1.4 to 1.3 Ga old igneous rocks, aqueously altered on Mars ~630 Ma ago. We test the theory that water-rock interaction was impact driven. Electron backscatter diffraction demonstrates that the meteorites Miller Range 03346 and Lafayette were heterogeneously deformed, leading to localized regions of brecciation, plastic deformation, and mechanical twinning of augite. Numerical modeling shows that the pattern of deformation is consistent with shock-generated compressive and tensile stresses. Mesostasis within shocked areas was aqueously altered to phyllosilicates, carbonates, and oxides, suggesting a genetic link between the two processes. We propose that an impact ~630 Ma ago simultaneously deformed the nakhlite parent rocks and generated liquid water by melting of permafrost. Ensuing water-rock interaction focused on shocked mesostasis with a high density of reactive sites. The nakhlite source location must have two spatially correlated craters, one ~630 Ma old and another, ejecting the meteorites, ~11 Ma ago.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Pickersgill, Dr Annemarie and Cohen, Dr Benjamin and Campanale, Mr Fabrizio and Lee, Professor Martin and Daly, Dr Luke and Chung, Mr Peter and Griffin, Dr Sammy and Hallis, Dr Lydia
Authors: Daly, L., Lee, M. R., Piazolo, S., Griffin, S., Bazargan, M., Campanale, F., Chung, P., Cohen, B. E., Pickersgill, A., Hallis, L. J., Trimby, P. W., Baumgartner, R., Forman, L. V., and Benedix, G. K.
College/School:College of Science and Engineering
College of Science and Engineering > School of Geographical and Earth Sciences
Journal Name:Science Advances
Publisher:American Association for the Advancement of Science
ISSN:2375-2548
ISSN (Online):2375-2548
Published Online:04 September 2019
Copyright Holders:Copyright © 2019 The Authors
First Published:First published in Science Advances 5(9):eaaw5549
Publisher Policy:Reproduced under a Creative Commons license

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
697411A journey from the solar nebula to planetary bodies: cycling of heat, water and organicsMartin LeeScience & Technology Facilities Council (STFC)ST/N000846/1GES - GES ADMINISTRATION
519741Follow the water: insights into the martian hydrosphere from nakhlitesMartin LeeScience & Technology Facilities Council (STFC)ST/H002960/1GES - GES ADMINISTRATION