Duck Bay Adventure - Page 26

Hi Hort
re. your #495

I wish I really had time to post properly again. I still have a month or so to go to finish a project which is taking up a lot of time and making it impossible for me to do reasonable checks etc. on the Mar's Rover releases (even to checking sol numbers from the exploratorium data)

So thanks for the comments.

The relevant images do look like wheel surface scuffs but I don't recall seeing one of these before with a distinct cavity in the side and with a thin layer of dust away from the scuff hole that has such a dscrete even edge resembling a liquid flow. I'll search, when I have time, for some of my scuff pictures to see if this feature was captured before. Anyhow the layer is obviously dry dust but it doesn't look to me like a characteristic layer of fine dry dust dislodged by Oppy's wheel movements, but I am most likely wrong.

I agree that the colour of the dust in the near side of the trench looks like that of the microchannel and I take Kye's point about the lack of berries in the body of soil in the microchannel. I wonder what is the reason for this?

Anyhow, thanks again.

Back to lurking

Winston

Hort / Extrasense

I forgot to add above that another reason for my suggesting that there was moisture involved was the tracks at the extreme lower right portion of the latest image. Look at those tracks at 2X. They look very much as if the rover took up some soil from just underneath the surface and SMEARED it on the evaporite rocks. They don't look like dust.

Winston

THis is the area I was referring to above (reply 502)

Winston

I doubt the idea that spherules where brought over to the soil surface from rocks or anywhere, since the sand/ground should have been formed after rocks where in place.

The spherules arrival then would be active during the the ground formation, and they would be present in the volume.

So the timeline needed to produce the surface only spherules population, does not seem to be reasonable.

Spherules should have to be formed on the current surface. Which means that they are not concretions.

e s

Horton, re your 500, Here is a Squyres paper from LPSC 2008 that explains why he thinks that the bright band is a diagenetic feature rather than a different sort of material starting from the time of deposition:

http://www.lpi.usra.edu/meetings/lpsc2008/pdf/2192.pdf

I can just see the bedding cutting diagonally across the bright band in this image of Cape St Vincent:

This is a tidy new fact but it doesn't help much to eliminate either of the two main sedimentary theories, as far as I can understand. The bright band is at different elevations at Endurance and Victoria, but the Athena team just tips this whole scene level in their past so that the water table could have been level. The Brine-splatters have suggested that sulphate might wick upward in the deposit in the aftermath of a big surge.

I have suggested that sulphate could be moved downward from the surface where it has always been present in the kilometers of dust that have moved over this landscape through geologic time. However, I'm not yet willing to accept that the bright band would have the same composition where it has been buried under Victoria's ejecta. It doesn't even appear bright all around the crater, but only intermittently.

The scuff deposit seems consistent with dry fine dust. I support Hort's concept though I think 1/2 to 1 billion years odd needs to be added to Boom. I don't think we can really get our mind around what is meant by a SLOW process on Mars.

Interesting that the paper Kye links shows a distinct fracture fill truncated at an erosional surface. Yes yes, I know, life the universe and everything can be attributed to impact surge. But the more information these amazing rovers garner the more likely the McLennan, Bell, Squires (and a host of other subject matter expert's)theory on the history of Meridiani becomes.

sol 1444 L234567R12345 wheel scuff here.

The full filter image does reveal differences in the undisturbed soil in the microchannel and the scuff.

Again, there are a few berries that are much darker than most.

What distinguishes these darker berries?

They have puzzled me since day one. Does anyone know of a paper that even discusses these oddities?

I did a comparison of the filter averages in a 5x6 box on a dark berry highlight and compared it to a nearby lighter berry highlight:

Filter - Dark/Light ratio

R7 - 0.70 L2 - 0.48
R6 - 0.56 L3 - 0.54
R5 - 0.53 L4 - 0.53
R4 - 0.51 L5 - 0.63
R3 - 0.53 L6 - 0.80
R2 - 0.57 L7 - 0.90

The darker berry is darker in all filters but darkest in the near red ( R4 ).

So, is it fair to conclude that the difference in the dark berries is the absence of a reddish coat?

Is the reddish coat "just" atmoshperic dust? If so why does the dust not "stick" to some berries?

Damn queer place, Mars.

When it comes to Mars, Hort's panoramas are definitive. If you can't hear a who in there, you are probably who hearing impaired. However MRO certainly has put a whole new slant on it.

Ceres - the fifth planet from a star called the sun. Smaller is better :

http://arxiv.org/abs/0711.1152

I'm not saying there are any who's there, and certainly everything is also highly modified and now all covered up, but this is another water planet. We're going to need another couple of deep space networks for sure, and the fact that we can also image nearby asteroids and asteroid flybys with these things is a real plus.

Brian, re your 506, I don't understand why the "fracture fill truncated at an erosional surface" is significant. If the lower strata of Cape Verde represent ancient dunes as Squyres thinks, then wouldn't the "erosion" involve the aeolian removal of sand? Does that mean that the fracture fill must have developed much later after the sand had lithified sufficiently to fracture? Maybe the fracture just did not propagate across the ancient boundary and has subsequently been filled.
There are often several plausible interpretations for any observation. Is there some way to interpret this "truncated fill" that proves something?

Speaking of expert opinion, here are two more independent Mars scientists, McCollom and Hynek, who look at the Meridiani sediments and interpret them most plausibly as surge deposits:

http://www.lpi.usra.edu/meetings/7thmars2007/pdf/3257.pdf

Brian, re your 506 and my 509, I've been thinking about the truncated fill. Maybe the important implication is that the deposition of the layered material must be well separated in time from the deposition of the fill material which would preclude, for example, using a single wet catastrophic event to explain both. That would be true for any fill though. I still don't understand if there are implications to the truncation of the fill.

Hi Kye,
My thinking goes this way. Previously the razorbacks that we have seen in both Endurance and Victoria were on the side of wider cracks (block edges) on the eroded crater slopes. But the fill in the super resolution of Cape Verde seems to be have developed in a thin, primary crack. So the crater slope razorbacks probably also formed in thin primary cracks which then widened as a function of desiccation. The Cape Verde vertical razorback must have developed after the sediment had lithified and cracked. The sandstone was subsequently eroded down and then another migrating sand dune event followed by lithification occurred. To me this termination of fill at an erosional boundary indicates that the fracture fill almost certainly occurred well prior to the Victoria impact.

The razorbacks are common to both Endurance and Victoria and this would make percolation of water through cracks more likely than vapour events or the residual alteration rinds I think you proposed. While only referring to the bright ring as being diagenetic, Squires hints that the physical aspects of the bright ring are supported by a geochemistry that indicates a retreating water table and the JPL press release states that the ring is attributed to the upper limit of the water table.
[link]

This concept seems to be supported by the long razorback that extends up to 'Smith' and fits the fact that the bedding cuts across the bright ring feature, which would seem to diminish any likelihood that the ring layers could have been surge events.

Regardless the Squires paper seems to have been hastily written (typos are not normally a feature of his careful work) and it will be interesting to see the geochemical workup when it becomes available.

3D of left scuff here.

Looks like Oppy is backing out.

Bummer. I was hoping this fracture fill aka rock hedge material would be studied closely:

sol 1421 3D "wiggle" animation of interesting area on rock in Lyell layer:

from 3D crossed eye pair here.

and "wiggle" of 3 and 4 image averages here

OK, I see lots of stuff worth a comment.

The white flat area seems to be the result of an instrument press on the rock. Er, was a "blueberry" compressed? A 5 pound force flattens a berry? Naaah.

Lots of linear features that will not "go away".

There is one curious more or less vertical "rod" capped by rock near the center of the animation.

More Mars weirdness.

Hi Hort

Thanks very much for your wiggle anims. I was thinking of doing some anims and 3-D anaglyphs of the same area myself but did'nt have the time.

Your wiggle anims are very suggestive of biology being intimately involved in the development of those "rock" surfaces at the "micro" level or as near to it as the Oppy imager will allow (think some kind of exotic martian coral).

Just think, Why would a putatively extremely dry environment, filled with dry very fine dust, result in the ubiquitous arrangement of that dust into the shapes that are characteristic of life on Earth?

We don't see featureless collections or clumps or masses of dust but lifelike organization.

Why would van der walls or other inanimate physical forces do this in the absence of life forces?

Practically everywhere on Meridiani is like that. We have been concentrating on the Berries but the lifelike, "cellular type" organization is seen in the SOD's, in the MI's of the evaporite surfaces and practically everywhere else.

I think we are letting the Scientists and their physical instruments and closed minds obscure the visual evidence of life that parades itself before us practically everytime we look at an MI of Meridiani Planum.

Winston

LWS
What we see is consistent with non biological erosion. And exactly what analogue to life on Earth do you see?

Yay!

Looks like Oppy has manouvered back in front of the Gilbert layer, closer to the rock in reply 512.

The Duck Bay adventure since the "toe dip" is now 160 sols old. a few more weeks and just this part of the adventure will be 2 nominal missions long!

Horton,

thanx for reminding me of the 3-d wiggle stuff. If I might be so bold, being older than most here, that's a mighty advantageous display technique for those of us who otherwise find their eyes get stuck viewing cross-eyed pairs.

Much easier on the brain too.

As usual, you've outdone yourself.

Hi Brian

Show me a picture of non-biological erosion effects at the near-micro level on Earth that resembles hort's wiggle anim above.

Read my #514 again re. the life analogue.

Once again, my main contention in these posts is that practically everyone is looking at meridiani planum as an area which is showing the effects of billions of years of erosion from a stage after the cataclysms.

I'm just saying; "whoa, couldn't it be the other way around?" Might we not be seeing a slow accretion of salts, etc and berries that has been going on for perhaps eons also but is totally different to what obtains on earth because the macro climatic conditions on Mars are so much different to Earth?

I'm also saying, don't entirely discount the slim possibility that there is an ongoing dynamic water, chemical and yes, microbial interaction at meridiani that produces the berries and guides the formation of the evaporite rocks right now and that erosion is only playing a small part in the structures that we see in the MI's that resemble aggregations of cells, etc.

I'm also saying that it is possible that the consensus position on erosion may be right but that we can't know for sure until better instruments or a human landing party can do more detailed studies, including on the ages of these structures. I also still have some problems with accepting the gospel that we are looking at surfaces that are billions of years old when rover tracks of mere months are completely obliterated, etc.

Winston

Hi Glennfish

I just had a look at your Nanotechnology site. It's fantastic. Extremely easy to read and totally informative. Could'nt you do something about the meridiani berries sometime down the road?

Winston

[i]Show me a picture of non-biological erosion effects at the near-micro level on Earth that resembles hort's wiggle anim above.[/i]

Aeolian and salt fretting will do that at such a scale. No I don't have a picture, but it is very common.