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

"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 *
****************
* SERIOUS, *
****************
* SARCASTIC *
****************
* OTHER? *
****************

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.

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

"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

Kurt Spunkle wrote:
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



oh foo, you beat me to it! LOL


- nate

"Nate Smith" wrote in message
...
Kurt Spunkle wrote:
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



oh foo, you beat me to it! LOL



Anyone up for a fishing trip?

"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? *
****************

hrtbreak wrote:

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?

Not to criticize your other speculations, but diatoms secrete
siliceous tests, not carbonate. There are other critters, of
course, that DO turn CO2 into CO3 in rocks.


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?


We don't really know how consolidated it is - it may not have had
to be under "extreme" pressure. On earth sediments lithify with
proper cement and not too much pressure. As for the tilting,
maybe by the impact process that formed the crater. Given the
small scale of the outcrop (about 4" they say), those would be
VERY thin lava flows. Possible, yes; probable - ?


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? *
****************




--
_____________________________________
Richard I. Gibson, Gibson Consulting
Gravity-Magnetic-Geologic Interpretations
http://www.gravmag.com

301 N. Crystal Street
Butte, Montana 59701 USA
Phone/Fax (406) 723-9639

Education Director, World Museum of Mining
http://www.miningmuseum.org

"Richard I. Gibson" wrote in
message ...
hrtbreak wrote:

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?

Not to criticize your other speculations, but diatoms secrete
siliceous tests, not carbonate. There are other critters, of
course, that DO turn CO2 into CO3 in rocks.
---clip---
See speculation qualifications below. My point was that if there were
carbonate-based rocks in large quantities, would there be all that free CO2
left in the atmosphere? We don't really know enough to guess what the
environmental cycles on this alien planet are like, but I had to start my
baseless speculations somewhere. Then again, there wouldn't be evidence of
"large quantities", either.

We don't really know how consolidated it is - it may not have had
to be under "extreme" pressure. On earth sediments lithify with
proper cement and not too much pressure. As for the tilting,
maybe by the impact process that formed the crater. Given the
small scale of the outcrop (about 4" they say), those would be
VERY thin lava flows. Possible, yes; probable - ?

When I wrote this, I think they were saying the formation was about a
foot-and-a-half tall. The weird soil mechanics seen around the landers
might be a factor in the formation process, too, I suppose.

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? *
****************




--
_____________________________________
Richard I. Gibson, Gibson Consulting
Gravity-Magnetic-Geologic Interpretations
http://www.gravmag.com

301 N. Crystal Street
Butte, Montana 59701 USA
Phone/Fax (406) 723-9639

Education Director, World Museum of Mining
http://www.miningmuseum.org