Abstract:
In the stratigraphic record of Camp Creek are episodes
of fluvial scour and fill thousands of years old.
Radiocarbon dates and the Mazama tephra, which serves as a
stratigraphic time line, temporally bracket episodes of
vertical aggradation and incision. Before 9000 years B.P.
the valley floor was scoured to the Tertiary bedrock.
Aggradation dominated since that time. Large cut-and-fill
structures indicate that two periods of erosion occurred
prior to incision of the modern arroyo. The first occurred
before 6800 yr B.P. and the second occurred approximately
3000 years ago. The modern arroyo-channel flows at or near
the Tertiary bedrock, is entrenched as much as nine meters
in the valley-fill alluvium and is thought to have
originated during the late 19th century.
