QUESTION:
How would I create Martian-like soil here on Earth?

ANSWER from Mary Urquhart on January 14, 1998:
Mars soil is similar to clay soils found near basaltic lava flows in places
like Hawaii.  Your best bet in Texas is to find a reddish clay or clay soil.
(I happen to know that some is common in certain parts of East Texas. I grew
up in Dallas and my family used to camp near lakes with beautiful red/yellow
clay.) The big problem with soils on the Earth is the high organic content
(including clays, like the black loam of Dallas, in addition to visible
plant bits.)

If you find reddish soil, first dry the soil throughly, then sift it (using
a flour sifter, but ask your parents before you use their's) for hard lumps
and plant pieces.  If the soil hardens into clumps during drying, try
breaking it up before sifting.  You should be left with a dry, dusty,
reddish soil.  As far as sterilization is concerned, that depends on what
you want to do with the soil. If you plan on heating it, do so AFTER the
above process to make sure it is the right consistency before you seal it
up.

Mary Urquhart                                    
Laboratory for Atmospheric and Space Physics  
University of Colorado at Boulder