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Geomorphology of Gale Crater, Rock on!
HSchirmer
post Jun 16 2019, 11:18 PM
Post #271


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QUOTE (serpens @ Jun 14 2019, 01:33 AM) *
(snip)
There is clear evidence that the sedimentary formations investigated by Curiosity since landing predominantly reflect fluvial lacustrine environments and the accessible 300 metre odd thickness of the Murray formation was laid down over some considerable time in a reasonably deep, neutral pH lake.
(snip)


There is a caveat there, layers of sediment on the bottom of a lake sample the conditions at the bottom of the lake.
If there's a neutral pH salt spring in an otherwise acidic or basic lake, the sediments record the neutral pH, because the neutral salt spring water is denser and accumulates in the depths of the lake.

Same problem with seasonal temperature and lake turnover.
Lake sediments in freeze-thaw climates are deposited at only two temperatures:
EITHER 4 Celcius wich is where water is densest, during winter, spring and summer, OR when the lake "turns over" in fall when the water is average ambient temperature.


Let's imagine a Mars where there is fine hydrophobic dust and fine hydrophilic dust.
You'll have a buoyancy gradient between those chemical particles, a constant wind might give you "tiger-stripes"
so that different chemicals from dust concentrate along the lake surface and only some reach the lake bottom.

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serpens
post Today, 01:30 AM
Post #272


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I don't think that a pseudo Langmuir circulation effect has any relevance to the Murray formation or indeed to the sum of data and analysis covering Curiosities traverse.
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