Abstract Detail

Paleobotanical Section

Sandau, Stephen [1].

An Eocene (Uintan) Aged Flora from the Uinta Basin, Utah..

Because of their fixed habit, plants are considered one of the better indicators of environmental conditions. In environmental reconstruction models, fossil plants are of particular value in that they record and convey important information about the local paleo-environment. Descriptions of Eocene floras from Utah’s Uinta Basin and surrounding areas of Wyoming and Colorado during the past century have dealt largely with fossil plants of the Green River Formation. Recently, a new flora has been discovered in the west-central part of the Uinta Basin in late stage Lake Uinta sediments. These plant bearing layers occur stratigraphically above the well-documented Green River flora by as much as 457m (1500ft). Whether these lacustrine sediments should be considered part to the Green River or the Uinta Formation has long been the subject of debate. Magnetostratigraphic data, however, shows a 5-6 million year span between these two floral groups. The nearby Wilson Creek area to the east and the Indian Canyon area to the west show magnetostratigraphic data in connection with Chrons C20n (43.5-42.5)-C19r (42.0-42.5). The presence of species of Macginitiea, Cardiospermum, Populus, Aleurites, and Cadrelospermum in the new flora represents plants adapted to seasonal conditions with high temperatures and low humidity. Although the assemblage is similar to the Green River flora some differences exist. Climate sensitive vertebrates (turtles Echmatemys, Baena, and crocodiles), along with this flora substantiates previous interpretations that warm temperatures prevailed throughout the mid-Eocene in the Uinta Basin.

1 - Brigham Young University, Geology, S389 ESC, Provo, Utah, 84602, USA

Keywords:
Eocene
fossil
paleocology
temperature
western North America
Uinta Basin
Utah.

Presentation Type: Poster
Session: 32-60
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM
Abstract ID:248