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Unmanned Spaceflight.com _ Mars _ Geology (April 2006)

Posted by: AlexBlackwell Mar 17 2006, 07:28 PM

Two new papers published in the April 2006 issue of Geology:

Cracks and fins in sulfate sand: Evidence for recent mineral-atmospheric water cycling in Meridiani Planum outcrops?
Gregory V. Chavdarian and Dawn Y. Sumner
Geology 34, 229–232 (2006)
http://www.gsajournals.org/gsaonline/?request=get-abstract&doi=10.1130%2FG22101.1

The Huygens-Hellas giant dike system on Mars: Implications for Late Noachian–Early Hesperian volcanic resurfacing and climatic evolution
J.W. Head, L. Wilson, J. Dickson and G. Neukum
Geology 34, 285-288 (2006)
http://www.gsajournals.org/gsaonline/?request=get-abstract&doi=10.1130%2FG22163.1

Posted by: RGClark Mar 17 2006, 08:15 PM

QUOTE (AlexBlackwell @ Mar 17 2006, 07:28 PM)

Is this referring to the "razorback" structures:

The 'Razorback' Mystery.

http://marsrover.nasa.gov/gallery/press/opportunity/20040716a.html

Anyone know how recent the article suggests they are?

- Bob Clark

Posted by: Bob Shaw Mar 17 2006, 11:40 PM

Bob:

Hmmm... ...they seem to be describing classic 'desert rose' formations.

Bob Shaw

Posted by: AlexBlackwell Mar 18 2006, 12:01 AM

QUOTE (RGClark @ Mar 17 2006, 08:15 PM)

Anyone know how recent the article suggests they are?

One should note that Chavdarian and Sumner use similar features in White Sands to analogize to Meridiani Planum, Mars. With respect to the word "recent" as they apply it to Mars, the authors, not surprisingly, are very careful in not giving a specific time interval. Having said that, I'll note that the authors refer to field work at White Sands in 2005 where changes were observed on the period of months:

QUOTE

In January [2005], cracks were ubiquitous along interdune-dune boundaries and across erosional surfaces on dune slopes. The cracked sand was moist and cohesive, consistent with active crack growth. In contrast, cracked sand on dune slopes in March [2005] and June [2005] was dry and not cohesive, and cracks were filled with loose sand, implying that cracks were not actively forming. Cracks were abundant; all exposures of cemented sand on stoss surfaces showed cracks once surficial sand was removed. Moist, actively forming cracks were present along the interdune-dune oundaries in March, but were absent in June [2005] when sand was dry.

Posted by: AlexBlackwell Mar 23 2006, 05:50 PM

QUOTE (AlexBlackwell @ Mar 17 2006, 07:28 PM)

The Huygens-Hellas giant dike system on Mars: Implications for Late Noachian–Early Hesperian volcanic resurfacing and climatic evolution
J.W. Head, L. Wilson, J. Dickson and G. Neukum
Geology 34, 285-288 (2006)
http://www.gsajournals.org/gsaonline/?request=get-abstract&doi=10.1130%2FG22163.1

For those without access to Geology, a 312 Kb PDF reprint is available http://www.planetary.brown.edu/pdfs/3256.pdf.

Posted by: BruceMoomaw Mar 25 2006, 08:35 AM

Chavdarian and Sumner's LPSC abstract on the subject is here: http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1888.pdf .

Posted by: RGClark Mar 25 2006, 07:23 PM

QUOTE (BruceMoomaw @ Mar 25 2006, 08:35 AM)

Chavdarian and Sumner's LPSC abstract on the subject is here: http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1888.pdf .

Thanks for that. I found on the MarkCarey.com/mars forum a link to a preliminary version of the paper, apparently an undergradute student thesis under the direction of a faculty adviser:

Cracks and Razorbacks: Pieces of Mars at White Sands National Monument, New Mexico.
http://www.geology.ucdavis.edu/~sumner/research/Chavdarian05SrThesis.pdf

And a link for images from the paper here:

http://www.geology.ucdavis.edu/~sumner/research/Chavdarian05Figures.pdf

Bob Clark