A Caltech Library Service

Diagenetic origin of nodules in the Sheepbed member, Yellowknife Bay formation, Gale crater, Mars

Stack, K. M. and Grotzinger, J. P. and Kah, L. C. and Schmidt, M. E. and Mangold, N. and Edgett, K. S. and Sumner, D. Y. and Siebach, K. L. and Nachon, M. and Lee, R. and Blaney, D. L. and Deflores, L. P. and Edgar, L. A. and Fairén, A. G. and Leshin, L. A. and Maurice, S. and Oehler, D. Z. and Rice, M. S. and Wiens, R. C. (2014) Diagenetic origin of nodules in the Sheepbed member, Yellowknife Bay formation, Gale crater, Mars. Journal of Geophysical Research. Planets, 119 (7). pp. 1637-1664. ISSN 2169-9097. doi:10.1002/2014je004617.

[img] PDF - Published Version
See Usage Policy.

[img] MS Word (Readme) - Supplemental Material
See Usage Policy.

[img] Image (JPEG) (Figure S1) - Supplemental Material
See Usage Policy.

[img] MS Word (Text S1) - Supplemental Material
See Usage Policy.


Use this Persistent URL to link to this item:


The Sheepbed member of the Yellowknife Bay formation in Gale crater contains millimeter‐scale nodules that represent an array of morphologies unlike those previously observed in sedimentary deposits on Mars. Three types of nodules have been identified in the Sheepbed member in order of decreasing abundance: solid nodules, hollow nodules, and filled nodules, a variant of hollow nodules whose voids have been filled with sulfate minerals. This study uses Mast Camera (Mastcam) and Mars Hand Lens Imager (MAHLI) images from the Mars Science Laboratory Curiosity rover to determine the size, shape, and spatial distribution of the Sheepbed nodules. The Alpha Particle X‐Ray Spectrometer (APXS) and ChemCam instruments provide geochemical data to help interpret nodule origins. Based on their physical characteristics, spatial distribution, and composition, the nodules are interpreted as concretions formed during early diagenesis. Several hypotheses are considered for hollow nodule formation including origins as primary or secondary voids. The occurrence of concretions interpreted in the Sheepbed mudstone and in several other sedimentary sequences on Mars suggests that active groundwater systems play an important role in the diagenesis of Martian sedimentary rocks. When concretions are formed during early diagenetic cementation, as interpreted for the Sheepbed nodules, they have the potential to create a taphonomic window favorable for the preservation of Martian organics.

Item Type:Article
Related URLs:
URLURL TypeDescription
Stack, K. M.0000-0003-3444-6695
Grotzinger, J. P.0000-0001-9324-1257
Kah, L. C.0000-0001-7172-2033
Mangold, N.0000-0002-0022-0631
Edgett, K. S.0000-0001-7197-5751
Sumner, D. Y.0000-0002-7343-2061
Siebach, K. L.0000-0002-6628-6297
Nachon, M.0000-0003-0417-7076
Blaney, D. L.0000-0002-4267-7939
Edgar, L. A.0000-0001-7512-7813
Rice, M. S.0000-0002-8370-4139
Wiens, R. C.0000-0002-3409-7344
Additional Information:© 2014 American Geophysical Union. Issue Online: 13 August 2014; Version of Record online: 22 July 2014; Accepted manuscript online: 21 June 2014; Manuscript accepted: 18 June 2014; Manuscript revised: 15 May 2014; Manuscript received: 28 January 2014. We would like to thank the scientists and engineers of the MSL team, especially the MAHLI, Mastcam, ChemCam, and APXS payload uplink and downlink leads. We also thank M. Chan and D. Loope for constructive comments that helped to improve this manuscript. All data used in this paper can be obtained by contacting the corresponding author.
Subject Keywords:Mars Science Laboratory; Yellowknife Bay; diagenesis; concretions
Issue or Number:7
Record Number:CaltechAUTHORS:20200828-150727637
Persistent URL:
Official Citation:Stack, K. M., et al. (2014), Diagenetic origin of nodules in the Sheepbed member, Yellowknife Bay formation, Gale crater, Mars, J. Geophys. Res. Planets, 119, 1637– 1664, doi:10.1002/2014JE004617
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:105152
Deposited By: Tony Diaz
Deposited On:28 Aug 2020 23:11
Last Modified:16 Nov 2021 18:40

Repository Staff Only: item control page