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Meridiani outcrop



 
 
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  #1  
Old January 26th 04, 11:17 PM
Timothy Demko
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Default Meridiani outcrop

My first impression of the much-talked-about Meridiani outcrop is that
it looks like a fractured, platey basalt flow, maybe even pahoehoe. In
the upper right hand corner of the PanCam image, right at the edge of
the picture, there are some interesting curvilinear features that look
like a ropey surface. On the other hand, I could also convince myself
that those features also look like an oblique section through very
large-scale trough cross-bedding (i.e. in a sandstone)...which would be
very, very cool if it is!

http://marsrovers.jpl.nasa.gov/galle...0P2303L2M1.JPG

However, the image is of fairly low resolution and zooming in too much
just makes it pixelated, of course. Jim Bell said at the briefing today
(1/26) that much higher resolution images will soon be taken for the
"Mission Success" 360 panorama. Hope they get them into a Maestro update
so we can thrash around in 'em, and have fun coming up with more
unfounded speculation!
--
Tim Demko
http://www.d.umn.edu/~tdemko
  #2  
Old January 27th 04, 04:05 PM
hrtbreak
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Default Meridiani outcrop


"Timothy Demko" wrote in message
...
My first impression of the much-talked-about Meridiani outcrop is that
it looks like a fractured, platey basalt flow, maybe even pahoehoe. In
the upper right hand corner of the PanCam image, right at the edge of
the picture, there are some interesting curvilinear features that look
like a ropey surface. On the other hand, I could also convince myself
that those features also look like an oblique section through very
large-scale trough cross-bedding (i.e. in a sandstone)...which would be
very, very cool if it is!---clip---


The exposed rock appears to have a fairly complex surface texture. So, are
we looking at the edge of a hole in a pre-impact lava flow (over the entire
plain) where an impactor tore through it? Broken and melted material from
an impact?

JJ Robinson II
Houston, TX
****************
* JOKE *
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* SERIOUS, *
****************
* SARCASTIC *
****************
* OTHER? *
****************

  #3  
Old January 27th 04, 04:23 PM
mlm
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Default Meridiani outcrop

Timothy Demko wrote in
:

My first impression of the much-talked-about Meridiani outcrop is that
it looks like a fractured, platey basalt flow, maybe even pahoehoe. In
the upper right hand corner of the PanCam image, right at the edge of
the picture, there are some interesting curvilinear features that look
like a ropey surface. On the other hand, I could also convince myself
that those features also look like an oblique section through very
large-scale trough cross-bedding (i.e. in a sandstone)...which would
be very, very cool if it is!

http://marsrovers.jpl.nasa.gov/galle...89114EFF0000P2
303L2M1.JPG

However, the image is of fairly low resolution and zooming in too much
just makes it pixelated, of course. Jim Bell said at the briefing
today (1/26) that much higher resolution images will soon be taken for
the "Mission Success" 360 panorama. Hope they get them into a Maestro
update so we can thrash around in 'em, and have fun coming up with
more unfounded speculation!
--
Tim Demko
http://www.d.umn.edu/~tdemko


If it isn't a basaltic outcrop, it will produce quite a few PhDs! I have
a feeling there is quite a bit of dust in the crevices of the outcrop
which influences your interpretation of cross-bedding (and striation).
The presence of an outcrop right in front of the rover amounts to a near
miracle (of course when we see what's over the crater rim we might
consider the find quite boring).

It will be exciting to check out opportunity's environs over the next few
weeks.

Mark.
  #4  
Old January 28th 04, 01:49 AM
Timothy Demko
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Default Meridiani outcrop

mlm wrote:
Timothy Demko wrote


My first impression of the much-talked-about Meridiani outcrop is that
it looks like a fractured, platey basalt flow, maybe even pahoehoe. In
the upper right hand corner of the PanCam image, right at the edge of
the picture, there are some interesting curvilinear features that look
like a ropey surface. On the other hand, I could also convince myself
that those features also look like an oblique section through very
large-scale trough cross-bedding (i.e. in a sandstone)...which would
be very, very cool if it is!

http://marsrovers.jpl.nasa.gov/galle...89114EFF0000P2
303L2M1.JPG

However, the image is of fairly low resolution and zooming in too much
just makes it pixelated, of course. Jim Bell said at the briefing
today (1/26) that much higher resolution images will soon be taken for
the "Mission Success" 360 panorama. Hope they get them into a Maestro
update so we can thrash around in 'em, and have fun coming up with
more unfounded speculation!


If it isn't a basaltic outcrop, it will produce quite a few PhDs! I have
a feeling there is quite a bit of dust in the crevices of the outcrop
which influences your interpretation of cross-bedding (and striation).
The presence of an outcrop right in front of the rover amounts to a near
miracle (of course when we see what's over the crater rim we might
consider the find quite boring).

It will be exciting to check out opportunity's environs over the next few
weeks.


Well, today's (1/27) briefing was very enlightening! The new PanCam
images definitely show fine-scale lamination, and the rest of the
panorama shows some very nice trough cross-bedding/cross-lamination! I'm
suprised that they had Andy Knoll (a paleontologist) did the briefing,
rather than John Groetzinger (a sedimentologist). Andy did a great job,
though, of explaining the significance of cross bedding.

http://marsrovers.jpl.nasa.gov/galle...20040127a.html

What really blew me away though, was to see how small that outcrop
really is! We're used to Spirit's grand vistas, and I, at least, was
fooled into thinking that the outcrop was much farther away, and bigger,
than it is. That crater is very small.

Now we have to get some mini-TES on those rocks. Cross-bedded sandstones
would be exciting enough, but just think about carbonates!
Stromatolites, even? (Thus, Andy Knoll's involvement...)

My speculation: cross-bedded sandstones, probably small-scale trough
cross-bedding from migration of 3D ripples. And yes, subaqueous...
--
Tim Demko
http://www.d.umn.edu/~tdemko
  #5  
Old January 28th 04, 03:05 AM
Kurt Spunkle
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Default Meridiani outcrop


"Timothy Demko" wrote in message
...
mlm wrote:
Timothy Demko wrote


My first impression of the much-talked-about Meridiani outcrop is that
it looks like a fractured, platey basalt flow, maybe even pahoehoe. In
the upper right hand corner of the PanCam image, right at the edge of
the picture, there are some interesting curvilinear features that look
like a ropey surface. On the other hand, I could also convince myself
that those features also look like an oblique section through very
large-scale trough cross-bedding (i.e. in a sandstone)...which would
be very, very cool if it is!


You've all got it wrong. Look at the panorama shot:

http://marsrovers.jpl.nasa.gov/galle...B003R1_br2.jpg


Start at the right side of the image and move to the left. It's a fossil!
You can clearly see the tail bones and vertebrae, as well as various belly
scales and what might be limb bones!

NASA can't cover it up much longer. There is life on Mars, probably living
in underground lakes and oceans! These fossils prove it!

Kurt

  #6  
Old January 28th 04, 04:34 AM
hrtbreak
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Default Meridiani outcrop


"Timothy Demko" wrote in message
...
mlm wrote:
Timothy Demko wrote---clip---


Now we have to get some mini-TES on those rocks. Cross-bedded sandstones
would be exciting enough, but just think about carbonates!

---clip---

The new images, especially in 3D, show what appear to be a number of other
depressions just beyond the one the MER is in. It's no wonder they got a
hole in one, if the course is all holes. There's also another, even more
prominent outcrop of bare rock visible in the distance.

Would one expect to see carbonates fixed in rocks when the atmosphere is
rich in CO2? Doesn't the large-scale fixation of CO2 in our atmosphere into
rock formations require living organisms, like diatoms? Assuming the stuff
we're looking at is built from layers of wind or water borne material, what
process converted it into rock? If it had to be under extreme pressure from
overlying layers to become rock, how would you get vertical movement of the
bedrock toward the surface without tectonic plates? Could you get this kind
of striation with many inundations of low-viscosity lava, for example?

Yes, I'm an engineer, but I didn't have anything better to do at the moment.


JJ Robinson II
Houston, TX
****************
* JOKE *
****************
* SERIOUS? *
****************
* SARCASTIC *
****************
* OTHER? *
****************

  #7  
Old January 28th 04, 07:40 AM
Schrodinger333
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Default Meridiani outcrop

http://science.nasa.gov/headlines/y2...ianiplanum.htm

"If the hematite occurs as a thin layer within a pile of layers, then it's
likely to have formed in a long-ago lake..."
  #8  
Old January 28th 04, 11:50 AM
Carsten
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Default Meridiani outcrop


"Timothy Demko" skrev i en meddelelse
...
My first impression of the much-talked-about Meridiani outcrop is that
it looks like a fractured, platey basalt flow, maybe even pahoehoe. In
the upper right hand corner of the PanCam image, right at the edge of
the picture, there are some interesting curvilinear features that look
like a ropey surface.


The curvilinear feature looks like a
dissolution/precipitation-mineralisation to me

On the other hand, I could also convince myself
that those features also look like an oblique section through very
large-scale trough cross-bedding (i.e. in a sandstone)...which would be
very, very cool if it is!


We'll soon be able to tell

In the meanwhile
What's the significance of a solid rock?

1) A fused volcanic ... a possibility
2) Cemented particles (being it layed out by wind, water or ejected)
Diagenetic processes is thorughly studied on Earth - all involving water.
What process would be working if not water?

/Carsten


  #9  
Old January 28th 04, 08:14 PM
mlm
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Default Meridiani outcrop

Timothy Demko wrote in
:

mlm wrote:
Timothy Demko wrote


My first impression of the much-talked-about Meridiani outcrop is
that it looks like a fractured, platey basalt flow, maybe even
pahoehoe. In the upper right hand corner of the PanCam image, right


Well, today's (1/27) briefing was very enlightening! The new PanCam
images definitely show fine-scale lamination, and the rest of the
panorama shows some very nice trough cross-bedding/cross-lamination!
I'm suprised that they had Andy Knoll (a paleontologist) did the
briefing, rather than John Groetzinger (a sedimentologist). Andy did a
great job, though, of explaining the significance of cross bedding.

http://marsrovers.jpl.nasa.gov/galle...20040127a.html


My speculation: cross-bedded sandstones, probably small-scale trough
cross-bedding from migration of 3D ripples. And yes, subaqueous...
--
Tim Demko
http://www.d.umn.edu/~tdemko

The new colour panorama of the outcrop lends even more depth to the
structure -- it is much too "red" though don't you think. The 3-D images
from yesterday gave good perspective on the shape, including an
interesting "bowl" at the far right of the face -- maybe a secondary
crater(?).

If you look at the descent images (DIMES) taken just before landing, they
show an interesting, brightly ringed crater (much larger that this MER's
hole) with what must be an even larger outcrop of bedrock at its bottom.
It looks to be quite a deep impact structure so observing strata down
there would be a real coup.

There do certainly appear to be fine layers in the hi-res photos Tim.
But stromatolite is a bit far fetched wouldn't you say? Imagine though
if you are partly right and it is sandstone -- that is a very exciting
prospect. You'd expect to find cherts and larger-scale crystalline
quartz as well if there was sandstone wouldn't you? Maybe it is

Oh lets go nuts and call it a slab of Martian marble -- what a truly
stunning dining room table it would make! Now that would be the find of
the century.

It is awe-inspiring to be at the brink of this discovery and be able to
sit here speculating.

Mark

  #10  
Old January 29th 04, 04:18 AM
Joe Knapp
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Default Meridiani outcrop


"mlm" wrote
The new colour panorama of the outcrop lends even more depth to the
structure -- it is much too "red" though don't you think.


I noticed that the Sol 4 images finally used some of the other filters,
specifically the red ones instead of just infra-red. Here's a straight
composite of the L4, L5 and L6 filtered images (r,g,b) of a section of the
outcrop. It's just a mechanical composite without changing anything, so not
saying it's "true" color, but still a different one:

http://www.copperas.com/astro/bedrock_rgb.jpg

Questions to geologists: are they still calling it bedrock? If so what is
the definition of that? Seems like they were saying it could be volcanic or
even wind-blown deposits. Is that defined as bedrock? Also, they were saying
that this is the first discovery of bedrock on Mars, but Dr. Squyres said
yesterday that the outcrop is just a small piece of a vast sheet the size of
Oklahoma, lying just under the surface. How do they know that if bedrock has
not been discovered before?

Joe

 




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