New optically stimulated luminescence ages provide evidence of MIS3 and MIS2 eolian activity on Black Mesa, northeastern Arizona, USA
| Autor: | Leslie D. McFadden, Shannon A. Mahan, Amy L. Ellwein |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
010506 paleontology
geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Optically stimulated luminescence Geochemistry Sediment Colorado plateau 01 natural sciences Arid Deposition (geology) Arts and Humanities (miscellaneous) Tributary General Earth and Planetary Sciences Aeolian processes Quaternary Geomorphology Geology 0105 earth and related environmental sciences Earth-Surface Processes |
| Zdroj: | Quaternary Research. 75:395-398 |
| ISSN: | 1096-0287 0033-5894 |
| Popis: | Eolian deposition on the semiarid southern Colorado Plateau has been attributed to episodic aridity during the Quaternary Period. However, OSL ages from three topographically controlled (e.g. falling) dunes on Black Mesa in northeastern Arizona indicate that eolian sediments there were deposited in deep tributary valleys as early as 35–30 ka, with most sand deposited before 20 ka. In contrast, the oldest OSL ages for sand sheets fall within the Pleistocene-Holocene climatic transition (~ 12–8 ka). Thus most eolian sediment accumulated on Black Mesa under climatic conditions that were in general cooler, moister, and more variable than today, not more arid, pointing to a considerable increase in sediment supply. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|