Delta, Estuary, and Lower Portion of the Channel of the Colorado River, 1933 to 1935

Delta, Estuary, and Lower Portion of the Channel of the Colorado River, 1933 to 1935

Delta, Estuary, and Lower Portion of the Channel of the Colorado River, 1933 to 1935

Delta, Estuary, and Lower Portion of the Channel of the Colorado River, 1933 to 1935

Excerpt

The Colorado River, some of whose present-day habits are intensively scrutinized by Godfrey Sykes in this paper, is the great master drainage course of our Pacific Southwest. It is a most remarkable stream. Heading through its tributaries in the lofty ranges of the central and southern Rocky Mountains more than a thousand miles from the sea, it threads a tortuous way across hundreds of miles of rugged and varicolored desert and high plateau. In this huge and region it is the only stream of importance. From much of this country it receives little or no contribution of water; instead it suffers loss of its substance continuously through rapid evaporation to the dry desert atmosphere. Some of the most striking scenic features of western North America have been carved by this river and its tributaries: The Flaming Gorge through the Uinta Mountains of northeastern Utah, the long Vermillion, White, Pink, and Book Cliffs of southern Utah and northern Arizona, and the Painted Desert and the Grand Canyon.

Not content, after wandering across sun-bleached wastes and through thundering canyons, to discharge into the sea through a normal river mouth on an ordinary coast, it ends its journey by pouring from the side into one of the most unique structural troughs known on the Earth's face. This is the depression, 1000 miles or more in length, occupied by the Gulf of California and its landward extension, the Salton Basin, embracing the Imperial and Coachella Valleys. This trough, like the one occupied by the Valley of the Jordan and the Dead Sea in Palestine, and like that forming the Gorge of the Rhine, resulted from subsidence of long, relatively narrow crustal blocks between faults or earth fractures. The crustal slices which subsided to form the Gulf of California lie between the branches of the great San Andreas fault, one of the longest known, reaching from the continental shelf off the coast of southwestern Oregon southward through California and the Gulf for some distance down the west coast of Mexico.

The floor of the Salton Basin-Gulf of California trough has been subsiding in recent geologic time and the sea would invade it some two hundred miles farther but for the fact that the Colorado River has been building an alluvial cone and delta across it concurrently with the subsidence. While marine waters filled a precursor of the present Salton Basin some millions of years ago, the present basin apparently has not been an arm of the sea which was eventually cut off by the Colorado River cone, as has been believed by some investigators. Instead it appears that the cone has been built up by the river as rapidly as the floor of the basin has sunk, a barrier a few tens of feet in height being thus maintained to exclude the Gulf.

Striking as have been the past constructional activities of the river in relation to the downsinking trough, the latest chapter of the river's history . . .

Search by... Author
Show... All Results Primary Sources Peer-reviewed

Oops!

An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.