Imperial College London
Professor John Cosgrove

ProfessorJohnCosgrove

Faculty of Engineering, Department of Earth Science & Engineering

Professor of Structural Geology
 
 
 
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Contact

 

+44 (0)20 7594 6466j.cosgrove

 
 
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Location

 

2.36ARoyal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Schieber:2016:10.1111/sed.12318,
author = {Schieber, J and Bish, D and Coleman, M and Reed, M and Hausrath, EM and Cosgrove, J and Gupta, S and Minitti, ME and Edgett, KS and Malin, M},
doi = {10.1111/sed.12318},
journal = {Sedimentology},
pages = {311--358},
title = {Encounters with an unearthly mudstone: Understanding thefirst mudstone found on Mars},
url = {http://dx.doi.org/10.1111/sed.12318},
volume = {64},
year = {2016}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - The Sheepbed mudstone forms the base of the strata examined by the Curiosity rover in Gale Crater on Mars, and is the first bona fide mudstone known on another planet. From images and associated data, this contribution proposes a holistic interpretation of depositional regime, diagenesis and burial history. A lake basin probably received sediment pulses from alluvial fans. Bed cross-sections show millimetre to centimetre-scale layering due to distal pulses of fluvial sediment injections (fine-grained hyperpycnites), fall-out from river plumes, and some aeolian supply. Diagenetic features include mineralized synaeresis cracks and millimetre-scale nodules, as well as stratiform cementation. Clay minerals were initially considered due to in situ alteration, but bulk rock chemistry and mineralogy suggests that sediments were derived from variably weathered source rocks that probably contained pre-existing clay minerals. X-ray diffraction analyses show contrasting clay mineralogy in closely spaced samples, consistent with at least partial detrital supply of clay minerals. A significant (ca 30 wt%) amorphous component is consistent with little post-depositional alteration. Theoretical modelling of diagenetic reactions, as well as kinetic considerations, suggest that the bulk of diagenetic clay mineral formation occurred comparatively late in diagenesis. Diagenetic features (synaeresis cracks and nodules) were previously thought to reflect early diagenetic gas formation, but an alternative scenario of synaeresis crack formation via fabric collapse of flocculated clays appears more likely. The observed diagenetic features, such as solid nodules, hollow nodules, matrix cement and ‘raised ridges’ (synaeresis cracks) can be explained with progressive alteration of olivine/glass in conjunction with centrifugal and counter diffusion of reactive species. Anhydrite-filled fractures in the Sheepbed mudstone occurred late in diagenesis when fluid pressures built up to ex
AU  - Schieber,J
AU  - Bish,D
AU  - Coleman,M
AU  - Reed,M
AU  - Hausrath,EM
AU  - Cosgrove,J
AU  - Gupta,S
AU  - Minitti,ME
AU  - Edgett,KS
AU  - Malin,M
DO  - 10.1111/sed.12318
EP  - 358
PY  - 2016///
SN  - 1365-3091
SP  - 311
TI  - Encounters with an unearthly mudstone: Understanding thefirst mudstone found on Mars
T2  - Sedimentology
UR  - http://dx.doi.org/10.1111/sed.12318
UR  - http://hdl.handle.net/10044/1/44405
VL  - 64
ER  -
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