Matijevic Hill detailed survey, Sol 3153 - 3290 Options

[ronald]

Some movement on sol 3153 to Copper Cliff:

Also visible in the Matijevic Pan.

Finished watching the two videos posted above - very interesting stuff - Thanks stewjack for posting the links!

[serpens]

Ronald, really nice presentation thank you. The choice of 3-d methods is very much appreciated.

[ronald]

Thanks

A quick one for sol 3155:

[Tesheiner]

Use this thread for all images, discussions, etc. post sol 3153.

[Stu]

Really looking forward to Oppy getting stuck into the rocks here...

[Bill Harris]

RE: the "NewBerries" discovered at this zone of the column:

Impact spherules as a record of an ancient heavy bombardment of Earth

Asteroids hitting Earth typically vaporize a mass of target rock comparable to the projectile’s mass. As this vapour expands in a large plume or fireball, it cools and condenses into molten droplets called spherules.

http://www.nature.com/nature/journal/v485/...ature10982.html

From my review of the literature and observations of the stratigraphy at the site, I am inclined to regard the "spherules of unknown affinity" simply as impact spherules.

--Bill

[dburt]

"Simply as impact spherules" may not be as simple as it sounds. Impacts can form spherule-like objects by multiple processes, including, e.g., condensation of silicate vapor to a glass, which you cited, condensation of sticky steam to mineral grains forming accretionary lapilli (e.g., the larger spherules stratigraphically associated with the Chicxulub Crater assumed to have killed the dinosaurs), hollow vesicles in impact glass later filled with minerals, or spherulites associated with devitrification (rapid partial crystallization) of impact glass (which spherulites characteristically have a radiating internal structure also noted at high magnification in some of the "newberries"). Multiple types of impact spherules might be expected to be preserved on Mars, much more commonly than on Earth, whose early impact record has been completely erased or is incomplete (biased by differential settling through sea water and heavily altered by aqueous processes).
-dburt

[ronald]

Fancy Vermilion - Sol 3156:

Big version here.

[serpens]

The interesting aspect on the provenance of these new-berries is their position towards the bottom of the original crater rim. This seems a most unlikely position for deposition of lapilli or condensation spherules originating with the Endeavour impactor and provides an indication that this is part of the pre-impact surface / sub surface.

[Stu]

Opportunity MI mosaic...

[ronald]

Some more Copper Cliff from sol 3156:

Could be a part of the Matijevic Hill Memory Game
Big version here.

[SteveM]

Opportunity MI mosaic...

Very pretty. Do any of the resident geologists have an idea of what kinds of processes could have produced those fine veins in this rock?

Steve M

[Eutectic]

Fracturing followed by fluids depositing the white mineral in the fractures. Brecciation is common with impact. We saw similar fine veins near the south end of Cape York. Here's a link to a picture of a terrestrial breccia; different scale, fracturing mechanism, and fracture fill, but the filled fracture idea is the same:

http://www.nr.gov.nl.ca/nr/mines/outreach/.../breccia1lg.jpg

[eoincampbell]

Does Vermilion look like a contact point between rock types that Steve Squyres alluded too in his recent AGU talk?

[serpens]

Really looking forward to Oppy getting stuck into the rocks here...

Me too, although interpretation will be a nightmare. For instance the Copper Cliff MI pan shows glass, spherules, angular and rounded clasts, tiny veins and possibly a clast within a clast. While this is a polymictic impact product we cannot assume that the glass and spherules are cogenetic. Cape York is probably giving us an insight into the multiple impact products of the Hadean but our understanding will be through a glass darkly.