On the Road Again - volume 4 - Page 8

Ben, I am not certain that this is a conglomerate in the classic definition. Yes it seems to be lithified sedimentary rock but it looks to be relatively homogenous deposit separating along fractures and erosion of less well cemented segments. False color imaging would be a good guide on this and sedimentation in a playa situation with a shallow channel would set the scene for what we see.

The findings at Erebus and Victoria have, IMHO, reduced the surge theory to a very very low probability option.

The dust accumulation does look a bit unusual, LWS. I appreciate your comment!

Just a quick update-- I went back and looked at NavCam images of the mast, and found that the dust started to accumulate after Sol-1714. There may be more images in this series taht I didn't catch, and there may be earlier dust accumulations prior to earlier cleaning events. This may not mean anything in the long run, it's just another data point for Meridiani Madness...

Here's hoping this works:

1714
[link]

1749
[link]

1770
[link]

1774
[link]

1776
[link]

1780
[link]

1782
[link]

1898
[link]

1961
[link]

2058
[link]

2086
[link]

2125
[link]

Here is the sol 2128 ( Jan 18, 2010 ) map position.

The sol 2128 move was a healthy 67 meters from the last position. Oppy is now about 160 meters from Concepcion crater.

There is an interesting 35 cm rock about 60 meters ahead. Maybe the first big chunk of rock from the fresh crater?

Great location map Hort; do you have one showing our position relative to Endeavour?

Serpens; I interpret the current Meridiani bedrock surface to represent an unconformity and the clasts are fragments eroded from the underlying Meridiani beds which have not travelled far.
The exotic loose gravel is probably heterogeneous lag material.
I can't estimate the hiatus between the Meridiani unconformity and the sand ripples but it could be a very long time in fact the ripples may have taken many millions of years before they were stabilized.
IMO many geologic processes on Mars took a really long period of time .

Exactly, Ben. We are travelling on an unconformity. The current erosional surface of the "Endurance Formation" and older erosional surfaces that have been exposed during crater formation and that has been recently been exposed by the shifting ripples. For the most part, the ripples are very slowly moving, the blueberries and coarser fractions tend to do a very good job of armoring the underlying sands. But every now and then we see an older erosional surface, and that is a good peek at the paleoenvironement of this area.

Look at the Navcam view of what is underfoot to-sol (Sol-212 :

I've not be able to figure where this is in the wider angle images.

Weve been traveling along essentially flat-lying strata, so we've not gone anywhere in the section. I think that is about to change. Conception crater is near a local topographic high and once we pass that feature we will be very close to starting downhill. Once we start downhill, we will more importantly start going down in the section. In other words, the surface will expose deeper strata. Things are going to get interesting.

Here is a rough DEM map, courtesy of the Univ of Berlin, HRSCview. Victoria is at the top, Endeavour is lower right corner, and the present location of Oppy is about halfway down the map and to the left of Victoria. Roughtly, Yellow is high, Green is inbetween and Blue is the topographic low.

http://hrscview.fu-berlin.de/cgi-bin/ion-p?ION__E1=UPDATE%3Aion%3A%2F%2Fhrscview.ion&image=3220_0001&image1=4+images&lat=-2.155&lon=354.576&zoom=5&mode=nd%2Bdtm&scale=19&pview=North&exag=1.5&viewport=900x600&image0=3220_0001&code=25146952&UPDATE.x=315&UPDATE.y=224

--Bill

Ben,
I follow the unconformity. Your explanation of heterogeneous lag material makes much more sense than my desiccation fragmentation. We went well below the old surface in Victoria and there were certainly disconformities evident - but no clasts. Any thoughts on what layer may be equivalent to what we see here? I guess the rover team have a good idea of what this is because they didn’t bother to take a closer look. Mayhap they will tell us one day.

>The pattern of the dust accumulation you >referred to in your #133 looks somewhat >like the water splats on the Phoenix wheel >strut.
>
>Thanks for your informative posts.
>
>Winston

The dust accumulation does look unusual, which caught my eye. I appreciate your comment.

We've seen dust accumlation on the solar panels and the sundial gnomon, so dust, by itself, isn't unusual. I went back, looked at Navcam images and was able to determine that this dust started accumulating after Sol 1714. There may be other Navcams, and I plan to look at Pancams to see if this dust is imaged. In the Big Scheme of things this is minor, but another data point in the Meridiani madness.

Here is a list of the Navcams that I've seen the dust on the antenna. I tried an earlier message with links to the images, but the forum server gakked on a dozen thumbnails and sent itot the bit bucket. Here is the slim version:

Sol
Image

1710
1N279996497EFF9489P0600L0M1

1714
1N280352800EFF94B2P1907L0M1

1749
1N283448473EFF94BBP1961L0M1

1770
1N285326827EFF94ITP1607L0M1

1774
1N285684574EFF94SCP1605L0M1

1776
1N285858670EFF9500P1930L0M1

1780
1N286203282EFF95DLP1962L0M1

1782
1N286380404EFF95EPP1957L0M1

1898
1N296673587EFFA1W1P1605L0M1

1961
1N302275380EFFA5ARP1978L0M1

2058
1N310889066EFFA9PDP1730L0M1

2086
1N316834706EFFAA00P1987L0M1

2125
1N316834706EFFAA00P1987L0M1

--Bill

Sorry for the doppel-post; that earlier msg that I thought got nuked was pulled out of the bit-bucket. Oh well, now you have links to the NavCam antenna images.

I did some checking on Oppy's activities and the antenna dust started to accululate during the conjunction stop-over at Santorini (Sols 1713-1770 or so). Remember that she departed from Victoria around Sol 1680. No ideas why the dust would start accumulating then, up to an including to-Sol (shows well on the NavCams today).

Closer and closer to Fresh Crater-- out of the ripple field and almost onto the bedrock route. Maybe by Friday?

--Bill

Here is the sol 2130 ( Jan 20, 2010 ) map position.

Today's drive was another healthy 67 meter backwards drive and it's about 100 meters to Concepcion crater. S0 - we should see a close view of the crater by Friday.

Any ideas why the crater is dark? I would have guessed a very fresh crater would have a lot of bright bedrock scattered about.

Bill, I freed the original post from the bit-bucket. Unfortunately, the forum software flags posts with a lot of links as "spam", I check the "spam" bucket ( It's an ugly job but someones gotta' do ot ) every few days or so.

Speaking of ugly...

Here is a montage of the antenna from sol 1492 to 2125:

I'll leave it to Bill to describe what's going on and to hypothesize about the incredible tenacity of the dust to stick to the antenna.

I was just looking at Hort's images of the two craters. Is it just me that has the impression that the distribution of the berries on the evaporite rock surfaces near to the craters seem to be somewhat different to what we have become accustomed to?

It seems that practically all the berries seem to be concentrated in the dust filling the cracks between the rocks (the mini channels) and on the dust dunes themselves. There are hardly any berries that can be seen peeping from the surfaces of the rocks.

Since these craters are supposed to be quite young (the youngest seen so far) Is this a possible indication that these rocks, presumably ejecta, might not have the theoretical berry component that they should have (all berries are supposed to have originated from the rocks) and the berries near these craters have come from elsewhere?

Winston

Hort-- Great, I was getting ready to start on a dusty-antenna montage. Yours will save a lot of work.

I honestly don't have the foggiest notion of what's going on... the nature of that dust accumulation is bizarre. But, we'll toss it out and be thinking it over.

On the dark tone of the rocks of Conception, I was thinking that broken rock has a rough, vertical surface and we're seeing something that is mostly shadowed. But I'm not so sure, those rocks look _too_ dark. We'll see it close-up soon enough.

Yep, the instant I hit "Post" I knew that the earlier post was a boo-boo. That many links cried "SPAM" and that many links can be a drag on server resources. I'll be carefuller...

I had a Lunar and Planetary Science Confererence paper by Tim Parker pointed out to me that has a nice topo map of our route. Currently, Oppy is about midway along the westernmost N-S leg. Within the next few weeks, she should start heading downhill and Down Section(!!!). And the views of Endeavour ought to improve (I've long since given up on "Heck of a View" predictions).

But, who knows. We'll see what we see when we see it...

--Bill

http://www.lpi.usra.edu/meetings/lpsc2010/pdf/2638.pdf

The sol 2131 drive was a short 20 meter backwards drive from the sol 2120 position. I don't see any obvious problems with the wheels so I don't know why it was so short.

The drive stopped a few meters short of a 25 meter clear stretch of bedrock towards the south.

Perhaps the plan is a forward autonav drive to the crater rim tomorrow???

I gave up a long time ago trying to get into the mind of the drivers.

Here's another one of these "linear features" cutting across a big ripple and the smaller ripples or grooves on it's surface. It crosses this image about one quarter from the bottom:

And it continues in this image:

(I think I may have seen another image of this feature in recent sols but I've done a little searching and not found it. )

Again, it seems weird how narrow it is. We've seen this sort of thing before correlated with fractures in the bedrock that extend out of sight under the ripple. But if the ripple is several centimeters deep what sort of influence would propagate upward without spreading out? Is this feature three-dimensional or just an interrupted line of color?

Bill Harris, re your 152, Don't forget that the assumption that movement downhill on these plains will be movement down-section is unproven. As the paper you linked points out, investigators are facing "persistent challenges" in determining if there was any movement up-section as Oppy climbed the 30 meters between Eagle and Victoria. Downhill is down-section where dealing with sediments that were laid down level and are still level. Hopefully, we shall see how true these assumptions are on the trek to Endeavour.

Hey, thanks, its great to hear that the LPSC 2010 Abstracts are out.

Sol 2131 Navcams are at Exploratorium and Pancams ought to be there in a while. Looks like tomorrow is the arrival day.

The antenna is a choked circular waveguide and so the apparent accumulation could possibly be an electromagnetic effect. The variations could therefore be determined by when the photos were taken in relation to transmissions and whether possible accumulated charge had bled off.

Or as Bill says, it could just be bizarre.

Kye, it may be wishful thinking-- I've been hoping for 6 years that we'll start moving downsection some day. Now that we are about to start downhill, maybe we will. But, without marker beds, we don't know where we are...

I've seen several lineations on the bedrock areas and I keep looking for expressions in the ripples (remember the Anatolia Features that we saw early in the traverse).

Pancams are up. One thing I notice is a lot of rubble (ejecta) _on_ the bedrock areas and less on the ripples. Says a lot about the mobility of the dust since this crater is only a "few years" old.

--Bill

sol 2131 R12 4x1 in next drive direction:

with a link to the 3D pairs.

The bedrock in this area is decidedly unflat. What's going on here geologically speaking?

FMR or Hort. Some posts seem to be missing.

Winston