Evolving subduction zones in the western United States, as interpreted from igneous rocks

P. W. Lipman; H.J. Prostka; R.L. Christiansen

doi:10.1126/science.174.4011.821

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Evolving subduction zones in the western United States, as interpreted from igneous rocks

P. W. Lipman·H.J. Prostka·R.L. Christiansen

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Abstract

Variations in the ratio of K 2 O to SiO 2 in andesitic rocks suggest early and middle Cenozoic subduction beneath the western United States along two subparallel imbricate zones dipping about 20 degrees eastward. The western zone emerged at the continental margin, but the eastern zone was entirely beneath the continental plate. Mesozoic subduction apparently occurred along a single steeper zone.

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Source-reported bounding extent: 31.724368695952563° to 48.97652831180986° latitude; -126.74221709761946° to -103.42282726016703° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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P. W. Lipman, H.J. Prostka, R.L. Christiansen. 1971. Evolving subduction zones in the western United States, as interpreted from igneous rocks. https://doi.org/10.1126/science.174.4011.821

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