Eocene woods of central Oregon

Abstract

Eocene terrestrial strata of central Oregon contain abundant and well-preserved fossil woods that are important for understanding past floristic diversity, forest structure, and climate.  In addition to the remarkably diverse and well-preserved Middle Eocene wood assemblage of the Clarno Nut Beds in the type area of the Clarno Formation in the John Day basin, there are well-preserved diverse Late Eocene wood assemblages from the vicinity of Post in the Crooked River Basin.  The Post assemblages discussed herein share some genera with the Nut Beds flora (Acer, Cercidiphyllum, Quercinium, Ulmus), but also include some new elements that remain to be described in detail, including woods referable to the families Anarcardiaceae, Fagaceae, Hamamelidaceae, and Juglandaceae. Comparison of the middle Eocene Nut Beds woods to the younger Post woods documents changes in climate, with the Post assemblages indicating increasing seasonality and an increase in deciduousness.

Keywords

Species diversity, carbon isotopes, radiocarbon dating, paleoecology, Eocene, paleoclimatology, paleobotany, paleobiology, fossil trees, climatic changes, Oregon, plant communities

Citation

Wheeler, E. A.; Manchester, Steven R.; Wiemann, Michael Carl. 2006. Eocene woods of central Oregon. PaleoBios. Vol. 26, no. 3 (Dec. 22, 2006): pages 1-6.