An iridium abundance anomaly at the palynological Cretaceous-Tertiary boundary in northern New Mexico

C. J. Orth; J. S. Gilmore; J.D. Knight; C. L. Pillmore; R.H. Tschudy; J.E. Fassett

doi:10.1126/science.214.4527.1341

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An iridium abundance anomaly at the palynological Cretaceous-Tertiary boundary in northern New Mexico

C. J. Orth·J. S. Gilmore·J.D. Knight·C. L. Pillmore·R.H. Tschudy·J.E. Fassett

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Abstract

An iridium abundance anomaly, with concentrations up to 5000 parts per trillion over a background level of 4 to 20 parts per trillion, has been located in sedimentary rocks laid down under freshwater swamp conditions in the Raton Basin of northeastern New Mexico. The anomaly occurs at the base of a coal bed, at the same stratigraphic position at which several well-known species of Cretaceous-age pollen became extinct.

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Source-reported bounding extent: 35.078782124856104° to 36.98949799286949° latitude; -109.03751829060221° to -103.04195147308809° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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BibTeX RIS

C. J. Orth, J. S. Gilmore, J.D. Knight, C. L. Pillmore, R.H. Tschudy, J.E. Fassett. 1981. An iridium abundance anomaly at the palynological Cretaceous-Tertiary boundary in northern New Mexico. https://doi.org/10.1126/science.214.4527.1341

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