| This boulder of highly contorted banded gneiss was derived
from the ancient crustal rocks exposed in the Little San Bernardino Mountains.
This rock is Proterozoic in age, probably between 1.5 and 2.0 Billion years.
The boulder was transported downstream by mass wasting, flash floods, or
debris flows before being deposited on the alluvial fans on the west flank
of the Little San Bernardino Mountains. Erosion has re-exposed the boulder
in the wash draining the uplifting Indio Hills. |