An iridium abundance anomaly at the palynological Cretaceous-Tertiary boundary in northern New Mexico
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. Copyright ?? 1981 AAAS.
Citation Information
Publication Year | 1981 |
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Title | An iridium abundance anomaly at the palynological Cretaceous-Tertiary boundary in northern New Mexico |
Authors | C. J. Orth, J. S. Gilmore, J.D. Knight, C. L. Pillmore, R.H. Tschudy, J.E. Fassett |
Publication Type | Article |
Publication Subtype | Journal Article |
Series Title | Science |
Index ID | 70011769 |
Record Source | USGS Publications Warehouse |