Spirit's hematite finding is in a rock dubbed "Pot of Gold," about the
size of a softball. "This rock has a shape as if somebody took a
potato and stuck toothpicks in it, then put jelly beans on the ends of
the toothpicks," said Dr. Steve Squyres of Cornell University, Ithaca,
N.Y., principal investigator for the rovers' science instruments. "How
it got this crazy shape is anyone's guess.
I haven't even heard a good theory yet."

I'll offer one then.

I don't find much choice but to take a start at considering it as an
erosional phenomenon.
I have previously posted a link to the only earthbound rock I have seen with
a comparable character:

http://www.sitecenter.dk/geocsite/ge...hots&UID=10064

It has glassy droplets sticking out in what I assess as a sedimentary rock
or atleast a softer rock than the glass. Weather this rock, which I call
Hedgehog, is a result of erosion in a beach-environment or weather it is
aerial abrasion is uncertain, but I picked it up on the beach (near Trodos
massif, Cyperus) ... If it indeed is a rock eroded in an energetic
environment as a sea-surf, it becomes fairly reasonable that a rock with a
similar composition/internal structuring could develop an odd exterior as
seen on 'pot of gold' in a less energetic environment as a subareal Martian
one without a wet/chemical component and one working over a prolonged period
of time.
It's obvious that 'pot of gold' has developed subaerially and my only
'second thought' is why comparable rocks has not been found on earth - since
the type of original rock is present here, or atleast the eroded spherules.
I can be convinced that 'pot of gold', even after Mars' standards, is an
extreme case and that the scarcity of this kind of rock here prevents
similar findings.
Well,... I postpone considerations on practical erosional phenomena: Why
does the erosion leave a stem?
An abrasive desert environment on Earth is probably different in character.
It has a strong abrasive component in the entrainment of sand in a saltating
population surging close to the ground. It's possible that such a process
has been active in the vicinity of 'pot of gold' (if memory serves me
right), but I would prefer a prolonged activity of a suspended fine
windborne fraction because the tuff spherules in such a process has a
stronger ability to influence the boundary-layer process: they provide the
sufficient lee to protect erosion closer to the rock.

my 2 cents worth

Carsten


Dr. Doug Ming, a rover science-team member from NASA's Johnson Space
Center, Houston, said, "There's apparently some type of weathering, a
removal of material, but we're still trying to determine whether it's
by chemical or mechanical processes."

snip