A 250,000-year climatic record from Great Basin vein calcite; implications for Milankovitch theory
Winograd IJ, Szabo BJ, Coplen TB, Riggs AC. 1988. A 250,000-year climatic record from Great Basin vein calcite; implications for Milankovitch theory. Science. 242(4883):1275-1280
A continuous record of oxygen-18 (delta oxygen-18) variations in the continental hydrophere during the middle-to-late Pleistocene has been obtained from a uranium-series dated calcitic vein in the southern Great Basin. The vein was deposited from ground water that moved through Devils Hole-an open fault zone at Ash Meadows, Nevada- between 50 and 310 ka (thousand years ago). The configuration of the delta oxygen-18 verus time curve closely resembles the marine and Antarctic ice core (Vostok) delta oxygen-18 curves; however, the U-Th dates indicate that the last interglacial stage (marine oxygen isotope stage 5) began before 147 +/- 3 ka, at least 17,000 years yearlier than indicated by the marine delta oxygen-18 record and 7,000 years earlier than indicated by the less well dated Antarctic delta oxygen-18 record. This discrepancy and other differences in the timing of key climatic events suggest that the indeirectly dated marine delta oxygen-18 chronology may need revision and that orbital forcing may not be the principal cause of the Pleisotcene ice ages.
- Type
- Journal Article
- Authors
- Winograd, Isaac; Szabo, Barney; Coplen, Tyler; Riggs, Alan
- Units
- DEVA
- Keywords
- Absolute Age, ash meadows, Calcite, Carbonates, Changes, Dates, Deglaciation, Devils Hole, Environment, Fault Zones, Fluctuations, Geology, Glacial Environment, Glacial Geology, Glaciation, Great Basin, Ground Water, insolation, interglacial environment, Isotopes, middle Pleistocene, Milankovitch theory, Nevada, North America, Nye County Nevada, O 16, O 18, Oxygen, Paleoclimatology, Periodicity, Pleistocene, Quaternary, Seasonal Variations, Sketch Map, south central Nevada, Stable Isotopes, Stratigraphy, Th, Upper Pleistocene, uranium disequilibrium, veins, Western U.S.