- journal_title：Geology
- Contributor：Noye M. Johnson ; Charles B. Officer ; Neil D. Opdyke ; Geoffrey D. Woodard ; Peter K. Zeitler ; Everett H. Lindsay
- Publisher：Geological Society of America
- Date：1983-
- Format：text/html
- Language：en
- Identifier：10.1130/0091-7613(1983)11<664:ROLCTI>2.0.CO;2
- journal_abbrev：Geology
- issn：0091-7613
- volume：11
- issue：11
- firstpage：664
The kinetics of continental rifting are recorded in the late Neogene sediments of the western Imperial Valley, California. The Gulf of California opened in its present form about 4 m.y. ago, capturing the Colorado River. Some 5 km of deltaic and fluvial sediments accumulated in the Vallecito–Fish Creek area during the interval 4.3−0.9 m.y. ago. Initial sedimentation rates were 5.5 mm yr−1, which diminished in an exponential fashion to 0.5 mm yr−1. When isostatic adjustments are accounted for, this implies tectonic subsidence rates of 1.5 mm yr−1, decreasing systematically to 0.1 mm yr−1. After 0.9 m.y. ago, right-lateral shearing along the Elsinore fault zone cut across the basin, causing it to be tilted and uplifted at a mean rate of 5.9 mm yr−1. The basin was concurrently rotated as a unit 35° clockwise. The dissected pediments and badlands that now characterize the area were formed and eroded in the past 0.9 m.y.