"Could the Meridiani Spherules be Surficial?" Options

[Kye Goodwin]

I have been reading the response to the reponse to impact-surge linked by Dr Burt in post 170. The MER team objects to the impact-spherule explanation because " The spherules are dispersed nearly uniformly across all strata." I agree that is a valid criticism. It is very much like Dr. Burt's criticism of the MER team's hypothesis, that spherule distributions are not consistent with any conceivable ground-water movement regime that should have controled the development of concretions. I agree strongly with this point of Dr. Burt's as well. Neither theory does a good job of explaining the distribution of the spherules. Also, neither theory does a good job of explaining why the spherules do not apparently disturb the bedding.

There may be a solution in a possibilty that I now raise with some trepidation. I think that there is a chance that the spherules are superficial, and not an integral part of the Meridiani strata at all. This probably sounds crazy to many readers, but before rejecting it outright remember that science is at kind of an impasse on this and could use a new idea. If the spherules are superficial this would explain a number of puzzling observations.

The layering at Homeplate and Meridiani is most simply explained by impact-surge. It is elegantly and inescapably explained by impact-surge. The impact-surge authors have also tried to explain the Meridiani spherules as part an impact event. If doubts are raised that the spherules are integral to the deposit, this would not in any way be inconsistent with the impact-surge origin of the layered structure. On the contrary, an objection to impact surge would be removed.

I intend to start another thread under Opportunity to discuss this question. The first posting should be mine and should be an organized outline of how it might be possible that the spherules have been mis-interpreted as part of the Meridiani layered deposit. I am working on it. If anyone wants to start in on me with the obvious objections, do it here for now. Maybe Dr. Burt would like to respond. No matter what the details of spherule formation in an impact or spherule deposition in the impact sediments, the very uniform distributions that we see are troublingly unlikely. Random distributions are possible from explosive dispersal but less likely than some kind of clustering because of the rapidly changing conditions in the surge cloud. The more-uniform-than-random distributions of spherules on rock characterised by MER-team analysis cannot be explained by impact surge.

[Kye Goodwin]

MarsIsImportant, If the spherules are superficial, that is, not really a part of the Meridiani layered deposits then neither theory needs to explain their distributions or their relationships with the bedding.

Doug, You never give an inch, do you, even for the sake of friendly debate? I do not need to prove that accretion is taking place at Meridiani, but only to raise doubts that it might be. I think it is reasonable to think that rock coatings might have formed at Meridiani based, yes, in part on the appearance of pre and post brushed surfaces. The little bits of bright material left behind at the base of those spherules encourage me because if they were unconsolidated dust they might have been removed by violent air currents close to the spinning brush. Here is the abstract for a talk in which several MER scientists discussed fracture fills and rock coatings at Meridiani, not as processes from an ancient warm-wet Mars but as something that could have happened under conditions more like those found today.

http://www.aas.org/publications/baas/v37n3/dps2005/424.htm

Did you get a chance to read that Kraft and Greely paper? They seem quite willing to accept that rock coatings formed at the Pathfinder site. The rinds like Lemon Rind were thought by the MER team to be added to the top of the Meridiani strata after all other deposition was complete. They haven't said that the rinds are recent, but I maintain that they might be. The rinds sometimes wrap the corners of eroded blocks and occur in the ejecta of not-so-ancient Beagle Crater.

My point is that erosion may not be the only process recently affecting the "rock" at Meridiani, which we should remember is barely rock at all. Spherules are embedded in "rock" allright but that is not proof that they formed or were deposited deep within the layered strata. This gets me to the MI evidence of the relationship between the spherules and the layers but I'll leave that for the next post.

[djellison]

Doug, You never give an inch, do you, even for the sake of friendly debate? I do not need to prove that accretion is taking place at Meridiani, but only to raise doubts that it might be.

It's not about 'giving an inch', and compared to other places, hell, this is still friendly if you ask me

You've proposed a theory on the origin of the spherules. I've raised some issues that I think question that theory- and yet you've twice posted about something else (coatings) rather than tackle the issues raised. Indeed - you're ignoring them. The Spherules in the rock are NOT the same for the full height of the endurance outcrops. They're different from the top to the bottom - and they're totally absent by the time you get to Erebus. You can not possibly explain that if you maintain a surface origin for them.

There IS evidence that they formed within the layers - bellybands have been observerd where they have formed and grown a little between layers - the berries will not have distored layers, the layers distorted the formation of the berries it would seem. Why does this make concretions more 'difficult' to believe. What terrestrial analogues for spherules-in-rock can you cite to say this is not the case? Some have appeared only AFTER a rat hole has been formed and thus catagorically not on a modern surface - unless you are suggesting that many MM's of sulphate / jarosite rich rock are being desposited today.)

If you've ever tried to cut a piece of hematite with a dremel or a drill, you'll know why they exhibit little erosion. A diamond tipped cutting machine takes a couple of hours to get through one, whereas the rock takes a few minutes.

Why is the transport of the berries so hard to imagine via wind...this is a wind that almost totally eroded a wheel track in less than a year. (infact, in the most recent case almost within a week) Imagine what it can do with a billion years.

If you're challenging other theories because you think they have issues, then you have to expect issues to be similarly raised about your own theory. It's not giving an inch - it's exercising the same critical thinking you say you're using with other theories. Of all the theories, it's the one that I have the hardest time buying.

And of course, the biggest issue of all...how do you creative hematite rich spherules on the surface of Mars?

These issues are not about giving an inch. If someone said "they were put there by the berry-ferry" but then couldn't explain how, or why, or answer to some of the contrary evidence then essentially all you've got is a belief system. That isn't science.

Doug

(I've merged the posts from the other thread into this one - they're sit slightly out of order, but it makes sense)

[climber]

...the Spherules in the rock are NOT the same for the full height of the endurance outcrops. They're different from the top to the bottom - and they're totally absent by the time you get to Erebus.

...and back on VC apron.
Question: The decision to land at Merdianii has been taken relying on data from orbit. Do we have finest (spacial) mesurements now where we can see Berries concentrations and absences?