QUESTION:
Are there any obvious holes in my theory of Mars evolution?

At one time Mars was covered with water ice and had a denser atmosphere, but
intense volcanic eruptions from Mt. Olympus or in combination with other
volcanos covered the planet with soot and ash. Barnacle Bill is volcanic
andesite feldspar and quartz and Yogi is basically basalt, therefore
probably volcanic ejecta. These catacysmic events created a green house
effect and melted the ice causing floods and eventually after the dust
settled destroyed most of the protective atmosphere. The water evaporated
into space over time and left the rusty, dusty planes of today. Rust which
you know is the result of iron oxidation, changing an Oygen rich envornment
into predominantely carbon dioxide. With polar ice the only remaining along
with vast underground water sheds. Amino acid or algea were able to
reproduce, possibly plants and microbes. but the hostile environment from
massive eruptions interrupted the lifeycle.

ANSWER from Peter Thomas on August 1, 1997:
Concerning Mars history, especially volcanoes, floods, and such:

Olympus Mons, and some other volcanoes, probably post date flood channels of
the main outflows.  The outflow channels also, seem to orginate from ground
water/ice storage, not from surface ice coverings.  Volcanic eruptions,
increased heat flow, etc, might have had something to to with melting ground
ice and causing the large outflow channles.

The volume of the outflow events, although obviously great from the areas
affected, probably did not involve much more than the equivalent of a few
meters or tens of meters water spread over the planet...more like big lakes
than oceans worth.