Field investigation of dried lakes in western United States as an analogue to desiccation fractures on Mars

Elmaarry, Mohamed Ramy; Watters, W. A.; Yoldi Martínez d. M., Zuriñe; Pommerol, Antoine; Fischer, D.; Eggenberger, U.; Thomas, Nicolas (2015). Field investigation of dried lakes in western United States as an analogue to desiccation fractures on Mars. Journal of Geophysical Research: Planets, 120(12), pp. 2241-2257. Wiley 10.1002/2015je004895

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Potential Desiccation Polygons (PDPs), tens to hundreds of meters in size, have been observed in numerous regions on Mars, particularly in ancient (>3Gyr old) terrains of inferred paleolacustrine/playa geologic setting, and in association with hydrous minerals such as smectites. Therefore, a better understanding of the conditions in which large desiccation polygons form could yield unique insight into the ancient climate on Mars. Many dried lakebeds/playas in western United States display large (>50m wide) desiccation polygons, which we consider to be analogues for PDPs on Mars. Therefore, we have carried out fieldwork in seven of these dried lakes in San Bernardino and the Death Valley National Park regions complemented with laboratory and spectral analysis of collected samples. Our study shows that the investigated lacustrine/playa sediments have (a) a soil matrix containing 40-75% clays and fine silt (by volume) where the clay minerals are dominated by illite/muscovite followed by smectite, (b) carbonaceous mineralogy with variable amounts of chloride and sulfate salts, and significantly, (c) roughly similar spectral signatures in the visible-near-infrared (VIS-NIR) range. We conclude that the development of large desiccation fractures is consistent with water table retreat. In addition, the comparison of the mineralogical to the spectral observations further suggests that remote sensing VIS-NIR spectroscopy has its limitations for detailed characterization of lacustrine/playa deposits. Finally, our results imply that the widespread distribution of PDPs on Mars indicates global or regional climatic transitions from wet conditions to more arid ones making them important candidate sites for future in situ missions.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Physics Institute > Space Research and Planetary Sciences
08 Faculty of Science > Physics Institute > NCCR PlanetS

UniBE Contributor:

Elmaarry, Mohamed Ramy; Yoldi Martínez d. M., Zuriñe; Pommerol, Antoine and Thomas, Nicolas

Subjects:

500 Science > 520 Astronomy
500 Science > 530 Physics

ISSN:

2169-9097

Publisher:

Wiley

Language:

English

Submitter:

Katharina Weyeneth-Moser

Date Deposited:

17 Jun 2016 15:45

Last Modified:

13 Mar 2018 17:02

Publisher DOI:

10.1002/2015je004895

Web of Science ID:

000368941100012

BORIS DOI:

10.7892/boris.81964

URI:

https://boris.unibe.ch/id/eprint/81964

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