Quaternary tephra from the Valles caldera in the volcanic field of the Jemez Mountains of New Mexico identified in western Canada
| Autor: | Giday WoldeGabriel, Nicholas J. G. Pearce, Henry C. Halls, John A. Westgate, René W. Barendregt, Michael P. Gorton, Andrei M. Sarna-Wojcicki, Emily S. Schultz-Fellenz, Colin J. Bray, Richard E. Kelley |
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| Přispěvatelé: | Westgate J.A., Woldegabriel G., Halls H.C., Bray C.J., Barendregt R.W., Pearce N.J.G., Sarna-Wojcicki A.M., Gorton M.P., Kelley R.E., Schultz-Fellenz E. |
| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
010506 paleontology
Paleomagnetism Early Pleistocene 010504 meteorology & atmospheric sciences New Mexico Geochemistry Fission-track dating Fission track dating 01 natural sciences Arts and Humanities (miscellaneous) Valles caldera Pumice Utah Caldera Tephra 0105 earth and related environmental sciences Earth-Surface Processes geography geography.geographical_feature_category Saskatchewan Volcano Gla Trace element General Earth and Planetary Sciences Quaternary Bandelier Tuff Geology |
| Popis: | A fine-grained, up to 3-m-thick tephra bed in southwestern Saskatchewan, herein named Duncairn tephra (Dt), is derived from an early Pleistocene eruption in the Jemez Mountains volcanic field of New Mexico, requiring a trajectory of northward tephra dispersal of ~1500 km. An unusually low CaO content in its glass shards denies a source in the closer Yellowstone and Heise volcanic fields, whereas a Pleistocene tephra bed (LSMt) in the La Sal Mountains of Utah has a very similar glass chemistry to that of the Dt, supporting a more southerly source. Comprehensive characterization of these two distal tephra beds along with samples collected near the Valles caldera in New Mexico, including grain size, mineral assemblage, major- and trace-element composition of glass and minerals, paleomagnetism, and fission-track dating, justify this correlation. Two glass populations each exist in the Dt and LSMt. The proximal correlative of Dt1 is the plinian Tsankawi Pumice and co-ignimbritic ash of the first ignimbrite (Qbt1g) of the 1.24 Ma Tshirege Member of the Bandelier Tuff. The correlative of Dt2 and LSMt is the co-ignimbritic ash of Qbt2. Mixing of Dt1 and Dt2 probably occurred during northward transport in a jet stream. |
| Databáze: | OpenAIRE |
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