Pristine Early Eocene Wood Buried Deeply in Kimberlite from Northern Canada |
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| Authors: | Alexander P. Wolfe Adam Z. Csank Alberto V. Reyes Ryan C. McKellar Ralf Tappert Karlis Muehlenbachs |
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| Affiliation: | 1. Department of Earth and Atmospheric Sciences, University of Alberta, Edmonton, Canada.; 2. Environment and Natural Resources Institute, University of Alaska, Anchorage, Alaska, United States of America.; 3. Department of Geoscience, University of Wisconsin, Madison, Wisconsin, United States of America.; 4. Institute of Mineralogy and Petrography, University of Innsbruck, Innsbruck, Austria.; The Pennsylvania State University, United States of America, |
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| Abstract: | We report exceptional preservation of fossil wood buried deeply in a kimberlite pipe that intruded northwestern Canada’s Slave Province 53.3±0.6 million years ago (Ma), revealed during excavation of diamond source rock. The wood originated from forest surrounding the eruption zone and collapsed into the diatreme before resettling in volcaniclastic kimberlite to depths >300 m, where it was mummified in a sterile environment. Anatomy of the unpermineralized wood permits conclusive identification to the genus Metasequoia (Cupressaceae). The wood yields genuine cellulose and occluded amber, both of which have been characterized spectroscopically and isotopically. From cellulose δ18O and δ2H measurements, we infer that Early Eocene paleoclimates in the western Canadian subarctic were 12–17°C warmer and four times wetter than present. Canadian kimberlites offer Lagerstätte-quality preservation of wood from a region with limited alternate sources of paleobotanical information. |
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