Old Delta Sediments
Posted by: 
brwhiz
N 42° 09.845 W 111° 49.916
12T E 431278 N 4668329
This valley floor was once under over 80 feet of water below the surface of ancient Lake Bonneville.
Waymark Code: WMJNZK
Location: Idaho, United States
Date Posted: 12/10/2013
Views: 5
Old Delta Sediments
Diverted into this valley by lava flows, Bear River deposited a huge, mostly red clay, delta here where it entered a vast inland sea that covered much of Utah.
Some 14,500 years ago, its shoreline here suddenly went down about 80 feet following an enormous discharge into Snake River. From then on, it gradually receded to become Salt Lake. Bear River then has to cut through and erode its old delta, forming steep sides and gullies you see here today.