Relative Dating of Terraces of the Owens River, Northern Owens Valley, California, and Correlation with Moraines of the Sierra Nevada

Abstract

AbstractIn the northern Owens Valley, the Owens River has cut and preserved three terraces uplifted above its modern floodplain. We have analyzed soils and used other relative-dating techniques in order to differentiate the terrace surfaces, to correlate from the terraces to moraines of the eastern Sierra Nevada, and to test the effects of relief and climatic differences on relative-dating results. Most of the relative-dating techniques attempted were successful in differentiating the terraces of the Owens River sequence. In addition, weathering rinds, soil descriptions, and an early Holocene14C date for the youngest terrace support correlation of the three terrace levels with the three post-Sherwin-age glacial stages (Tioga, Tahoe, and pre-Tahoe) found in nearby canyons of the Sierra Nevada. Other relative-dating techniques that are commonly employed, however, suggest distinct differences between the terrace and moraine sequences. These differences probably reflect the difference in relief, such that slow erosion of the moraine crests may have retarded soil development relative to the flat terrace surfaces and altered surface-weathering processes. Use of relative-dating analyses to correlate between dissimilar geomorphic systems requires caution but use of a broad range of techniques and absolute-age calibration may make correlation possible.