http://SaturnianCosmology.Org/ mirrored file For complete access to all the files of this collection see http://SaturnianCosmology.org/search.php ========================================================== /Palaeogeography, Palaeoclimatology, Palaeoecology/, /Volume 76, Issues 3-4/, /January 1990/, /Pages 349-366/ Kenneth L. Cole *Abstract* The paleoecological reconstruction of Pleistocene deserts along the Colorado River of western North America is attempted using data from fossil packrat middens. The Colorado River drainage is set into a physiographic context along a gradient from the hyperarid Colorado Desert to the moist high elevations on the Colorado Plateau. The Pleistocene and modern distributions of individual plant species along this corridor are compared emphasizing records from the Picacho Peak area of the Colorado Desert and the eastern Grand Canyon. In general, plant species are now distributed 700–900 m higher in elevation and 400–700 km further up-river than they were during the late Wisconsin, however, some plant species have not conformed to the general pattern emphasizing the individualistic nature of species distributions in time. /Palaeogeography, Palaeoclimatology, Palaeoecology/, /Volume 76, Issues 3-4/, /January 1990/, /Pages 331-348/ Owen K. Davis *Abstract* Caves have been a valuable source of paleoenvironmental information since the eighteenth century. In arid portions of western North America, caves have replaced small lakes as the primary source of biotic remains of Quaternary age. Packrat middens, dung of extinct animals, pollen, and archeological artifacts are excellently preserved. Aridity of the sediment, which is influenced by the cave's topographic position, internal morphology, and the regional climate, is the primary cause of good preservation. For stratigraphic pollen analysis, the best sites are those without internal moisture sources and without extensive bioturbation. Pollen samples should be taken near the center of the chamber, where eolian deposition is most rapid. Pollen concentrations in cave sediment are lower (2000–355,000 grains g^−1 ) than in lake sediment, and pollen percentages in cave sediment differ from those in packrat middens due to additional transport mechanisms (on plant tissue and on the packrats themselves) for middens. Pollen diagrams for Bechan Cave, Utah, and Organ Pipe Cactus National Monument, Arizona are presented as examples of cave sediment and packrat midden analysis.