SEDIMENTOLOGIC STUDIES OF THE COLORADO DELTA.
Final rept. 1 Jul 64-30 Jun 66,
UNIVERSITY OF SOUTHERN CALIFORNIA LOS ANGELES DEPT OF GEOLOGY
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The report reviews the work accomplished under the original contract including literature review, sedimentologic data analysis, and surficial characteristics of the Colorado Delta with emphasis on the lower portions of the delta. The Colorado is distinctive since it is a major delta built under highly arid climatic conditions. This special climatic setting produces a very different assemblage of surficial types with barren mud flats predominating, and salinas second in importance but with marshes a negligible type in contrast to most other major deltas such as that of the Mississippi River where marshes are the dominant surficial form. The lack of peat deposits may also contribute to the much less evident compaction subsidence of the delta and the relatively stable form of the feature since its first exploration some four centuries ago. A second unusual condition is that the delta is situated in the graben formed by one of the major active fault systems of the world. Thus faulting and active movement of a tectonic nature are the major influences on the form of the delta. Traces of scarps can be seen on aerial photographs of the deltaic plain. Several problems are evident for future research including a study of the clay mineralogy of this delta, particularly in areas of exceptionally high salinity tectonic effects on sedimentation and rates of accretion.
- Geology, Geochemistry and Mineralogy