First of all, we have to agree that there is evidence pointing to 'cataclysmic events' as you call them, as per the link I gave earlier. In other words, the causes you will attribute to the geologic formation you point out will probably be the same as I do . The issue then is how long ago did this occur.
This becomes difficult to analyse since mars is far and so limited testing has been done. But as you said, for liquid water to be we need an atmosphere. And of course this brings two questions:
1- What is the minimal atmospheric pressure required for liquid water to exist.
2- Since there is little atmosphere left around mars, how much time would it take for this atmosphere to go off into space ?
I know 6000 years doesn't seem like a lot when we are used with millions and billions, but it still is a shitload of time and before saying it isn't long enough for the atmosphere of to go away, we would have to do the calculations.
I have looked for the equations for this but haven't found them. Unfortunetely, from what I understand of the problem, it requires some knowledge of statistics and thermodynamics, two subjects which I have yet to encounter at university (hopefully next year).
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And finally, I have to ask what is the difference between a valley and a plain for example that makes the valley become a sign of long ages ? For all I know, a plain is formed by gigantic ice sheets which also take a rather long time to form and melt.
What I'm saying is that every geological feature in a naturalistic point of view is sign of great age. Heck, the planet is sign of a load of time since by natural means, it probably takes more then a couple millions years to form.
In other words, how is a canyon different from a valley, a plain, a planet, a sun in terms of being a sign of long age ? If I say God created the sun, does it become omphalism because it takes a billion years for a hydrogen cloud to collapse and become a sun ?
Edited by slevesque, : No reason given.