Exploring Mt Sharp north of the dunes - Part 1: Beyond Pahrump Hills, Site 45-50, Sol 923-1147, March 12-October 28, 2015 Options

[elakdawalla]

Finally drove away from Pahrump Hills on sol 923. Wheel tracks sure are piling up at the end of the drive -- there seems to have been quite a bit of slip.

[admin note: I was going to start a new thread for this, but realized our thread naming may be a bit out of whack because we're really not journeying to Mt Sharp anymore, are we? We'll discuss it with admins and I'll move/rename posts when we figure out our naming schema.]

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[Arizona Dave]

Regarding the veins and the fractures, the thing Im trying to understand is this:

These vein outcrops occur near the lower elevations of this large crater, Mt Sharp and the Rims being anywhere form 2 to 3.5 miles higher in elevation. Its now widely accepted that where Curiosity is exploring was under water far longer than previously estimated, and then that water slowly evaporated, leaving behind layered sedimentary rock layers and other tell-tale signs of long periods of a "shallow sea".

So, if these veins are the result of minerals precipitating under high pressure, then this would mean these veins formed under Several Kilometers of overburden...and now they are been exposed due to "erosion" the questions are:

a) Being near the bottom of Gale crate, rather than the top, where did the KM's of rock and overburden erode to? Erosion goes downhill, there isnt anywhere for KM's to have eroded to, The crater prevents excavation of sediment outside of the rim (thus all erosion remains inside the crater) - and

There is clear evidence of surface water at this location, and that it was under water at different shallow depths for perhaps billions of years...so, that situation in effect negates the overburden hypothesis, because again, the surface water action evidence is side-by-side with the veins.

Is it more possible this is non-pressure related, and more ancient heat/hydrothermal in nature?

If we accept Mars has been pretty dry for the last Billion years, then we are seeing something that had been roughly the same for a billion years...those flaky paper-thin wafer of rock resting in position where they are well above the surface show the wind load isnt enough to move them...so certainly not KM of overburden were removed simply by wind.

Im thinking Non Terrestrial erosion and mineralization mechanisms need to be considered...Mars has no Techtonic plates, and less water no matter how long it existing, and 2/5th the gravity, meaning erosion forces far less than earth...

Id love to hear some thesis on how these veins are so near the surface - thx.

[centsworth_II]

...so certainly not KM of overburden were removed simply by wind.

Barring an error in my quick math, an average of 1mm removed per 100 years will lead to 10 km removed in a billion years.

[Arizona Dave]

Barring an error in my quick math, an average of 1mm removed per 100 years will lead to 10 km removed in a billion years.

Yes, mathematically thats correct, but "Where" did the material go?

a) Not all overburden is "dust/sand" at least 50% of overburden would be hard rock and thus at least 50% of that overburden could not be moved by wind, thus it cannot be located outside of the crated, rocks dont roll uphill.

Where does the 1mm/year data come from? 1mm/yr is a HUGE amount of material, and 1mm/yr assume 100% of that 1mm/yr was removed from the crater and deposited somewhere else...this brings up another interesting question: Does dust and sand only get removed from the crated to higher areas, or does dust also get blown in from outside the crater and deposited to Lower areas (dust and sand usually settles to lower/depressed areas over time)

c) WHERE did 1mm per year go? Only outside the crater?

d) at 1% of the earth's atmosphere, 100mph winds on mars would exert the force of a 1mph wind on earth...living in AZ for 20 years, dust storms simply dont happen in winds under 30-40 mph, and we certainly dont get 1mm of dust/sand per year removed or deposited in AZ...The dust in Mar's atmosphere is very fine dust, due to the lack of air compared to earth, so what mechanism not only eroded, but excavated all that material to Only Outside the crater?

Gale Crater itself is known to be as old or older than the sea/lake that they now know existed there. Mars' entire geology is entirely different than Earths...craters since almost he beginning of its forming still exist...while 99% of Earths craters and been sublimated via Plate Tectonics, and mass erosion.

Im really asking as serious question here, I dont see the mechanism to not only erode, but then Move the Kilometers of material away...not only that, but the clear signs of surface water, with the Veins Fracturing those surface water features means that the veins formed After? the water was lost, or at least When the Water was there...this them means Kilometers of Overburden were not only Deposited over the area to create the pressures required to form them, but then subsequently that same material was removed...

It had to come from somewhere and then it had to go somewhere...Or, the veins were formed under Low pressure/Surface conditions.

I think its absolutely fascinating whatever they are and however they formed...The paper thin wafer pieces all over are especially intriguing. Viewing these images in Streoscopic makes 2D photos seem bland.