Varnished Colorado River gravel on ancient terrace surface
![Oblique view of flat surface mantled with tightly packed, well-rounded cobbles & pebbles, shiny reddish-brown to black surface](/index.php/styles/full_width/public/thumbnails/image/DSCN3077_2014FEB17.jpg?itok=5ypMbjhN)
Detailed Description
Linear tracts and small patches of well rounded and varnished pebbles and cobbles mark the traces of ancient channels, bars, and floodplain terraces of the lower Colorado River. Extremely long durations of exposure to the desert environment transform the surfaces of these deposits to flat, and tightly packed pavements of spectacularly discolored and varnished river rocks.
Sources/Usage
Public Domain.