Skip Links

USGS - science for a changing world

Open-File Report 2013–1242

Mechanical Properties of Simulated Mars Materials—Gypsum-Rich Sandstones and Lapilli Tuff

By Carolyn Morrow, David Lockner, and Chris Okubo

Introduction

Observations by the Mars Exploration Rover (MER) Opportunity, and other recent studies on diagenesis in the extensive equatorial layered deposits on Mars, suggest that the likely lithologies of these deposits are gypsum-rich sandstones and tuffaceous sediments (for example, Murchie and others, 2009; Squyres and others, 2012; Zimbelman and Scheidt, 2012). Of particular interest is how the diagenesis history of these sediments (degree of cementation and composition) influences the strength and brittle behavior of the material. For instance, fractures are more common in lower porosity materials under strain, whereas deformation bands, characterized by distributed strain throughout a broader discontinuity in a material, are common in higher porosity sedimentary materials. Such discontinuities can either enhance or restrict fluid flow; hence, failure mode plays an important role in determining the mechanics of fluid migration through sediments (Antonellini and Aydin, 1994; 1995; Taylor and Pollard, 2000; Ogilvie and Glover, 2001). As part of a larger study to characterize processes of fault-controlled fluid flow in volcaniclastic and gypsum-rich sediments on Mars, we have completed a series of laboratory experiments to focus on how gypsum clast content and degree of authigenic cementation affects the strength behavior of simulated Mars rocks. Both axial deformation and hydrostatic pressure tests were done at room temperature under dry conditions.

First posted November 21, 2013

For additional information, contact:
Contact Information, Menlo Park, Calif.
Office—Earthquake Science Center
U.S. Geological Survey
345 Middlefield Road, MS 977
Menlo Park, CA 94025
http://earthquake.usgs.gov/

Part or all of this report is presented in Portable Document Format (PDF). For best results viewing and printing PDF documents, it is recommended that you download the documents to your computer and open them with Adobe Reader. PDF documents opened from your browser may not display or print as intended. Download the latest version of Adobe Reader, free of charge.


Suggested citation:

Morrow, C., Lockner, D., and Okubo, C., 2013, Mechanical properties of simulated Mars materials—Gypsum-rich sandstones and lapilli tuff: U.S. Geological Survey Open-File Report 2013–1242, 11 p., http://dx.doi.org/10.3133/ofr20131242.

ISSN 2331-1258 (online)



Contents

Introduction

Sample Preparation

Experimental Procedure

Results and Discussion

Conclusions

References

Figures


Accessibility FOIA Privacy Policies and Notices

USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
[an error occurred while processing this directive] URL: https://pubs.usgs.gov
Page Contact Information: Contact USGS
Page Last Modified: Thursday, November 21, 2013, 11:57:11 AM