Both the historic vertical control record and the late Quaternary geologic history suggest that the existing divide between the sub–sea-level Salton basin and the Gulf of California is maintained in part by tectonic uplift. Comparisons among the results of first-order levelings referred to the San Diego tide station indicate that the southern Imperial Valley, immediately north of the crest of the Colorado River delta, rose more than 0.40 m during the period between 1926–1927 and 1973–1974 and collapsed in part between 1973–1974 and 1978 for a net uplift of about 0.15 m. This geodetic evidence, combined with geologic observations, suggests that continuing crustal swelling along the deltaic crest during latest Holoccne time has biased the flow of the Colorado River away from the Salton basin and toward a course along the southeast flank of the delta and into the Gulf of California.

First Page Preview

First page PDF preview
You do not currently have access to this article.