Cape York - The "Lakelands", Starting sol 2703 Options

[Phil Stooke]

A circular version of mhoward's nice new panorama.

Phil

[dilo]

Marvellous, guys! Starts to recall me Spirit Odyssey on Husband hill!

[jvandriel]

Another Navcam L0 view taken on Sol 2710.

Jan van Driel

[fredk]

Some comments on Chester Lake (and a false colour (?!) pancam view) here. "Paraphrased" from Squyres:

The new target should be IDD'd... it looks bright and Noachian itself... Need to build a nice story here and relate it to the Tisdales... We think there might be a coating, so we'll have to choose a target carefully and at least APXS it... Consider RAT'ing it to get into its guts...

It is something entirely new, or SOS ("Same Old Sulfates")? This is our first major Noachian target, so let's make it count.

I wonder what about it "looks Noachian"...

[Matt Lenda]

Some comments on Chester Lake (and a false colour (?!) pancam view) here. "Paraphrased" from Squyres:I wonder what about it "looks Noachian"...

Had me fooled, too. I asked myself that all day.

The EOSs and SOWG meetings are particularly cryptic these days; these guys talk and head and shoulders above my comprehension!

-m

[marsophile]

Maybe it is the orbital images of that locality that look Noachian rather than that specific rock.

[Phil Stooke]

The new target is Salisbury... my home town! - I mean the one in Wiltshire, not one of the Salisburys in the colonies.

Phil

[Stu]

Another magnifcent view...



Full size version here: http://twitpic.com/6iynsp/full

[serpens]

I wonder what about it "looks Noachian"...

It looks like an impact breccia, integral to the weathered rim of a crater that pre-dated the Meridiani sediment formation. Could it be anything other than a Noachian construct?

[Bill Harris]

True that, Serpens. The geomorph of this area is more complex and convoluted than we we assume or possibly can imagine. It's like standing on a small chunk of the Canadian Shield and figuring out depositional environments with a handlens and a Brunton.

Ah, the comparative simplicity of seven years on the playa may have spoilt us...

--Bill (almost giddy with anticipation over impending MI's and APXS)

[SteveM]

Could some of you tell a non-geologist what kinds of questions the new detail we're encountering might answer. What more will we learn about the history of Mars -- besides the overly mentioned issue of water.

Steve M

[Phil Stooke]

We don't know all the details, but it seems the sulfate and blueberry rocks of the plains we've just left were formed in a relatively brief period in the middle of Martian history. Water was there, and probably very salty and foul-tasting water! - not very pleasant for life. These rocks at Cape York are much older, and may have formed in very different conditions. What we hope to learn is, what were those conditions? Warm or cold? Reducing or oxidizing conditions? Acidic or alkaline? Lots of water or only a bit? Water in the ground, or melting out of overlying snow? So we would expect evidence of water, but it's the environmental conditions that are most important.

Phil

[Bill Harris]

That is it, exactly. When a rock like basalt weathers, in the presence of water, it breaks down into clay minerals (the phyllosilicates in the news) and various anions and cations ("minerals" dissolved in the water). The type of clays, and other weathering byproducts, is dependent on the ionic makeup of the water to begin with, as well as the temperature and whether the environment was oxidizing or reducing. By looking at the weathered zone on the hill, we can tell what the conditions were way back then.

--Bill

[Stu]

Thanks Bill and Phil, that's a really clear, really useful explanation of the significance of this place. Much appreciated.

[ngunn]

There is the complication of deciding whether any clays that may be found were formed by weathering of the basalts before the impact or after brecciation and deposition on the crater rim. It's not an easy puzzle.