Potassium-argon ages from the Mount Taylor Volcanic Field, New Mexico

Peter W. Lipman; Harald H. Mehnert

doi:10.3133/pp1124b

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Potassium-argon ages from the Mount Taylor Volcanic Field, New Mexico

Peter W. Lipman·Harald H. Mehnert

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Abstract

Fourteen new K-Ar dates for volcanic rocks of the Mount Taylor field, New Mexico, indicate that most activity occurred between 4.3 and 1.5 m.y. (million years) ago. Peak activity was at about 3.0-2.5 m.y., both on the central andesite-rhyolite shield volcano and on the surrounding alkali basalt-trachyte volcanic plateau, and occurred concurrently with an episode of NNE-trending basin-range faulting. The K-Ar dates also indicate that the regional Ortiz pediment surface, graded to the ancestral Rio Grande, existed in the Mount Taylor area as recently as 3 m.y. ago and that 250-400 m of erosional downcutting has occurred in subsequent time. Growth of the Mount Taylor field was also concurrent with peak volcanic activity along the northeast-trending Springerville-Raton zone, a major late Cenozoic volcanic belt that is considered to reflect the presence of a regional structural discontinuity of Precambrian age in the North American craton.

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Source-reported bounding extent: 35° to 35.375° latitude; -108° to -107.25° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Peter W. Lipman, Harald H. Mehnert. 1980. Potassium-argon ages from the Mount Taylor Volcanic Field, New Mexico. https://doi.org/10.3133/pp1124b

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