JimO wrote:

msnbc.com (Oberg): "Avoiding the 'F word' on Mars -- F*SSIL"
NASA won't speculate about possibility of fossils, but that doesn't mean
others aren't
http://msnbc.msn.com/id/4480097/


Now that I've had a chance to look at the Ottawa, Ontario website (I
think you overloaded his server with your article!) and having been an
amateur paleontologist for around 30 years, I think he may well have a
point here in regards to some of these things being real fossils; I
thought it was very strange that most of the "Blueberries" seemed to be
approximately the same size, and his close-up of this one in particular:
http://aix1.uottawa.ca/~weinberg/mar..._pop_p_037.jpg does seem to
show that they are attached to some sort of a root or stem structure,
with a connection point, as shown on these pictures:
http://aix1.uottawa.ca/~weinberg/mar...mple_m_039.jpg
http://aix1.uottawa.ca/~weinberg/mar...alls_m_025.jpg
But the one that really tipped the scales in my opinion is this one:
http://aix1.uottawa.ca/~weinberg/mar...tica_m_034.jpg
If I had found this while rockhounding, I would have had no doubt that I
was looking at a fossil, due to the equal sizes of the segments that
make up the object.
Regarding the voids that appear in the rocks (vugs) they may well be due
to dissolved crystals that were in the rocks at their formation... but I
have had excellent luck when fossil hunting by breaking open rocks that
have such voids, as they are often caused by dissolved shells of
mollusks and brachiopods that are exposed to weathering on the rock's
exterior, intact fossilized examples of which will be found inside of
the rock in question. Looking for rocks with "dents" on the outside is
my favored method of identifying ones worthy of further examination
when many rocks are present.

Pat

P.S. For amateur rockhounds- always look at the _bottom_ of any rock
before tossing it aside; I came within a second or two of tossing away a
rock that had a bit of coral on top, only to find out it had a beautiful
crystal-covered snail shell set into a cavity in the bottom.

P.P.S. On the other hand, limit this suggestion to smaller sized rocks-
the thin flat limestone ones over say three feet wide sometimes will
have a large wasp nest under them, and they are very persistent in their
pursuit of the person who tips their house upside down.