8255

• UCREFRP Catalog Number: 8255
• Author: Grams, P. E. and J. C. Schmidt.
• Title: Geomorphology of the Green River in the Eastern Uinta Mountains, Colorado and Utah.
• USFW Year: n.d.
• USFW - Doc Type: Logan, Utah.
• Copyright Material: NO

Grams and Schmidt 1

1. INTRODUCTION
Bedrock gorges and deep canyons are among Earth's most spectacular landscapes.
Canyons are found on most continents and occur where major drainages cross topographic
barriers. The geomorphic organization of canyon-bound rivers is determined by (1) the
characteristics of the bedrock into which the canyon has been eroded, (2) the
characteristics and frequency of hillslope and tributary sediment delivery to the trunk
stream, (3) the hydrology of the trunk stream, and (4) the characteristics and volume of the
sediment load of the trunk stream. The relative influence of these factors in determining
channel geometry, longitudinal profIle, and distribution of alluvial deposits has only been
investigated in a few places, especially the 400-km long Grand Canyon in northern
Arizona.
The purpose of this paper is to describe the role that bedrock lithology and
structure and tributary sediment delivery play in determining channel and floodplain
geomorphology in the canyons of the Green River in the eastern Uinta Mountains of
Colorado and Utah (Fig. 1). The geomorphic character of this stream is evaluated by
examination of channel geometry, longitudinal profile, and patterns of alluvial deposition
and erosion. The study area is located at the northern edge of the Colorado Plateau and
includes a diverse assemblage of lithologies and geologic structures that influence the
pver's geomorphology. Data collected and analyzed for this study include: detailed
surficial geologic maps of the river corridor, surveyed channel cross sections, and bed-
material measurements. The geomorphic organization of the Green River in the Uinta
Mountains is compared to Grand Canyon and generalized to the Colorado Plateau.
2. PREVIOUS WORK
Perhaps the most extensive canyons in the United States are found in the Colorado
Plateau, a large region of uplifted sedimentary rocks. The disparity between the
orientation of present stream courses and trends of dominant geologic structures causes the
largest rivers of the region totglverse diverse geologic formations of varying erosional