Glauconite from the Precambrian belt series, Montana

R. A. Gulbrandsen; S. S. Goldich; H.H. Thomas

doi:10.1126/science.140.3565.390

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Glauconite from the Precambrian belt series, Montana

R. A. Gulbrandsen·S. S. Goldich·H.H. Thomas

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Abstract

Glauconite from the upper part of the Missoula Group of the Belt Series, Flathead County, Montana, has been dated at 1070 million years by potassium-argon and rubidium-strontium analyses. This is the first glauconite of Precambrian age reported in North America.

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Source-reported bounding extent: 47.80212064650814° to 48.99701773220832° latitude; -116.07442097910472° to -114.18360215485701° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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R. A. Gulbrandsen, S. S. Goldich, H.H. Thomas. 1963. Glauconite from the Precambrian belt series, Montana. https://doi.org/10.1126/science.140.3565.390

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