On my fifth day at Zzyzx Road (Thursday, March 22) we turned our
attention to the soil mechanics and chemistry of the Mojave
National Preserve. We traveled with soil experts from the
Natural Resources Conservation Service to conduct several digs
of soils typical of this area. About one mile off I-15 along the
south side of Zzyzx Road we climbed a low hill and dug a small
trench into the soil about three feet deep, keeping the upper
slope sharp so that we could look at the soil profile. At first
glance this hill would seem to be volcanic (that’s what I
thought as I drove past it coming in) but it had a mixture of
rocks carried down to it from uphill, and the hill itself is
probably an erosional remnant. Across the freeway we could see
similar layers, mostly ancient, tilted limestones. Digging down,
we found fairly well sorted layers, some containing mostly sand,
others small pea gravel, etc. About six inches down was a hard
white layer that looked almost like chalk – which is what it
basically turned out to be