Poster

         Paleobotany

Late Eocene wood assemblages from the Crooked River Basin, Oregon

Presenting Author
Elisabeth Wheeler
Description
Well-preserved silicified woods are common in the Pacific Northwest. Three localities near the town of Post, Oregon, provide insights into the late Eocene vegetation and climate ca 36 million years ago and data for comparing with both older and younger wood floras of region. All three localities contain some woods with features unique to present-day genera, some referable to family but not to genus, some referable to order, and some whose affinities could not be determined. Locality 1 -  Brummer’s Spring (UF 254) includes a Cedreloxylon (Meliaceae), three types or Rosaceae wood,  one type of Laurinoxylon (Lauraceae), Malvaceae. Locality 2: Dietz Hill locality (UF 278) includes woods with features of  the Asian endemic  Keteleeria (Pinaceae), as well as Magnolia, Carya, Aesculus,, Quercus, Cupressaceae, Araliaceae, Fabaceae, Sapindaceae, Urticalean Rosids, two types of Laurinoxylon (Lauraceae), and a palm.  Locality 3: Post Hammer (UF 279) contains Pistacia (Anacardiaceae), Celtis (Cannabaceae), Acer (Sapindaceae), Pterocaryoxylon (Juglandaceae), Wataria (Malvaceae). Platanoxylon (Platanaceae), and Fagus (Fagaceae) occur at all three localities. These woods and taxa identified from silicified fruits and seeds of similar age represent a diverse assemblage of warm temperate to subtropical woody plants, some with East Asian affinities. Comparing the wood functional traits of  the late Eocene Post assemblage to the older Clarno Nut Beds (mid-Eocene) woods and to the younger woods associated with Oligocene Bridge Creek flora attests to increased seasonality and cooling climate in the region.