Cordilleran Section - 103rd Annual Meeting (4–6 May 2007)

Paper No. 5
Presentation Time: 2:50 PM

THE LATEST EOCENE BADGERS NOSE FLORA OF THE WARNER MOUNTAINS, NORTHEAST CALIFORNIA: THE “IN BETWEEN” FLORA


MYERS, Jeffrey A., Department of Earth Science, Western Oregon University, Monmouth, OR 97361, myersj@wou.edu

The 34-35 Ma Badger's Nose flora of the east face of the Warner Mountains, northeastern California, is the only known latest Eocene assemblage from the region between the Willamette Valley of western Oregon and central Colorado. It fills a gap in the paleobotanical succession of the interior Pacific Northwest between the late Eocene Whitecap Knoll flora (~ 38.5 Ma) and earliest Oligocene (33.6 Ma) assemblages of the Bridge Creek flora. Badger's Nose vegetation consisted of Metasequoia-dominated lake margin woodland that lacked both the abundant and diverse lianas of middle Eocene floras, such as the Clarno flora, as well as the diverse temperate hardwoods and conifers of the early Oligocene Bridge Creek flora. The composition of the flora was also intermediate, forming a low diversity assemblage that included both thermophilic holdovers from the warm middle Eocene as well as temperate elements that later comprised the Bridge Creek flora. Many taxa are similar or identical to those in latest Eocene and Oligocene floras of both the coast and the Cordillera. Not surprisingly, the moist, warm temperate Badger's Nose climate was intermediate between that of the middle Eocene and that of the Oligocene, capable of supporting a few hardy warm temperate/subtropical plants, as well as some cooler temperate plants. The Badger's Nose flora is truly an “in between” assemblage and reflects accrued floristic and vegetational migrations and extirpations caused by climate changes of the late Eocene, and is a precursor to the rise of diverse temperate forests of the Oligocene.