Hydrogen isotopes in Eocene river gravels and paleoelevation of the Sierra Nevada.
نویسندگان
چکیده
We determine paleoelevation of the Sierra Nevada, California, by tracking the effect of topography on precipitation, as recorded in hydrogen isotopes of kaolinite exposed in gold-bearing river deposits from the Eocene Yuba River. The data, compared with the modern isotopic composition of precipitation, show that about 40 to 50 million years ago the Sierra Nevada stood tall (>/=2200 meters), a result in conflict with proposed young surface uplift by tectonic and climatic forcing but consistent with the Sierra Nevada representing the edge of a pre-Eocene continental plateau.
منابع مشابه
Provenance of Eocene river sediments from the central northern Sierra Nevada and implications for paleotopography
[1] Geochronology of fluvial deposits can be used to characterize provenance, the paleotopography of sediment source regions, and the development of regional drainage systems. We present U‐Pb and (U‐Th)/He ages of detrital zircon grains from Eocene gravels preserved in several paleoriver systems along the western flank of the central and northern Sierra Nevada. These ages allow us to trace the ...
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ورودعنوان ژورنال:
- Science
دوره 313 5783 شماره
صفحات -
تاریخ انتشار 2006