Meridiani Perspective

http://www.msss.com/mars_images/moc/2003/11/15/2003.11.15.M0301935.gif

This pre-MER landing MGS image is a great example of erosion at work and how the process has re-exposed several formerly buried craters in Northern (Sinus) Meridiani. Eagle and Endurance craters no doubt experienced a similar exhumation to the eventual condition we see them in today (the arrows indicate craters that are emerging from beneath layered material). The depth of burial of Eagle and Endurance post impact remains to be determined.

This image also demonstrates the magnitude of material removed from the meridiani deposit (and redistributed) to expose the craters and the amount of material remaining. When viewed in this perspective the geologic time interval examined at Eagle and Endurance represent just a minute fraction of the events that occurred to deposit these sediments.

Good example.

It puts an interesting perspective on the section of Meridiani around Endurance. Where exactly does the balance stand between erosion and deposition today?

Erosion appears to be winning, and this makes sense in terms of the desert pavement landscape that dominates the plains.

From the perspective of permacrust, has the permacrust persisted in areas that have had past traces of water? What makes (or made) a deposition environment on Mars?

I'd still say that topographical relief has had an enormous influence on the rate of erosion.

I think the pavement retards erosion.so at first it would have been very fast ersion as there would be few berries, then once it built up to where it is now on top ersion will be very slow and posibily starting to the deposition point now or soon.

What makes (or made) a deposition environment on Mars?

Alde, that's a very big point needing consideration for meridiani. If the deposits, which are hundred of meters thick, are sedimentary, what was the source and mode of transport of the sediment. A typical terrestrial source such as highlands and the means of transport in the form of a drainage system are not yet obvious. If the deposits are evaporites, consider the amount of water needed to evaporate to get the hundreds of meters of salts. The amount is significant. Unless tectonic movement has occurred in the vicinity of meridiani that raised the layered deposits or lowered the basin margins, there are many questions in need of answers. Aeolin and or volcanic sources could be part of the sediment equation. Compared to Gusev crater which has an apparent sediment source the meridiani "basin" needs work.

Even on the volcanic side, we don't really understand the origins of Martian volcanics.

On Earth, the vast majority of volcanic activity is associated with tectonic plates, and such volcanoes are relatively young.

If we look at the volcanoes on Earth, past and present that are not associated with plate tectonics as possible Martian analogs, that leaves us with hot spots associated with Magma chambers, and possibly short-lived shield events associated with impact.

Perhaps this topic needs a new thread.