on Titan: Is That Saturn's Moon Titan or Utah?
Hmm, perhaps. But I don't agree that White Canyon, Utah is representative of karst topography at all. The interesting area certainly hosts an array of classic slot canyons (I've engaged in canyoneering in some of them) but there's no significant limestone and/or gypsum present. Here's the geologic map and stratigraphic column for your perusal.
Friday, March 5, 2010
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Thanks for posting this!
ReplyDeleteAreas just outside Sikun Labyrinthus in PIA10219 (http://photojournal.jpl.nasa.gov/catalog/PIA10219) appear morphologically similar to Polygonal Karst, Tower Karst, Corrosion Plains, and Poljes (see abstract for images). We are referring to the Sikun Labyrinthus area proper as a “fluviokarst-like terrain”, this is what we were comparing to White Canyon. A fluviokarst is where both dissolution and fluvial erosion processes occur. A detailed 2-page LPSC abstract is freely available here: http://www.lpi.usra.edu/meetings/lpsc2010/pdf/1544.pdf
The comparison to White Canyon, UT was made based on apparent drainage density, scale, and also pattern. There is a small section of Sikun Labyrinthus that looks like an exact match to a section of White Canyon Utan, both in scale and pattern. The LPSC poster had a side by side image of Sikun Labyrinthus and White Canyon, but unfortunately this wasn’t part of the press release (it was only black and white). The similarities in the side-by-side version were downright spooky. However, one major morphological difference between the two areas is that White Canyon does not have closed valleys, while Sikun Labyrinthus does.
Is White Canyon, UT “karstic”?
Howard et al [Howard , A.D. et al., "Sapping Features of the Colorado Plateau: A Comparative Planetary Geology Field Guide", NASA, Washington, DC, 108 pp. freely available pdf article (9.2 Mb download): http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19890001030_1989001030.pdf]
described sapping features in the Colorado Plateau, including the White Canyon area. In the Cedar Mesa sandstone, among others, Howard et al. mention that “solutional removal of calcite cement has locally created karstic landforms on slickrock slopes.” (Howard et al., p. 13). So at a small scale, karst-like processes can occur on Colorado Plateau sandstones to form weathering pits and runnels. Can it be responsible for larger scale features like valleys?
In comparing steephead valleys in the French Jura (a karst plateau) to the Colorado Plateau, it was noted that “sapping canyons of similar length and length:width proportions [to reculees in the French Jura] are well developed in the massive resistant sandstones of the Colorado Plateau, where dissolution is considered only a minor contributor (Howard et al., 1988) but perhaps is a critical one.” [Ford and Williams, Karst Hydrogeology and Geomorphology, Wiley, 2007, p. 365).
[As an aside, karst is now recognized as being possible in sandstone and quartzite (silica) rocks as well.
Wray, R.A.L. Cave and Karst Science 24 (1997) 81-86. “Quartzite dissolution: karst or pseudokarst?”
(freely available as html): http://www.speleogenesis.info/archive/publication.php?PubID=16
The Bungle Bungles region of Australia is a tower karst formed in quartzite sandstone. The Gran Sabana in Venezuela (of Angel Falls fame) contains many karst features in the quartzite plateau (tepui).] For recent work, see (pay-for article): Piccini and Mecchia, Geomorphology 106 (2009) 15-25. “Solution weathering rate and origin of karst landforms and caves in the quartzite of Auyan-tepui (Gran Sabana, Venezuela).” Doi: 10.1016/j.geomorph.2008.09.019]
Thanks for your interest!
-Mike Malaska
March 20, 2010