The Keystone Thrust Fault lies just west of Las Vegas. It clearly shows
Paleozoic rocks (left) thrust over Mesozoic rocks (right). This is the same
relationship found in the giant fields of the Wyoming/Utah thrust belt with the
main difference being the help from the Colorado River in exhuming the buried
faults. The structures in Nevada have been in tact for the last 65 million years
and the seals on these structures have not been compromised by unproven,
theoretical extension faults.

Photos courtesy of Alan Chamberlain, CEDAR STRAT