2015 GSA Annual Meeting in Baltimore, Maryland, USA (1-4 November 2015)

Paper No. 17-12
Presentation Time: 11:00 AM


BLACK, Morgan1, BROOKE, Sharon1 and O'KEEFE, Jen2, (1)Earth and Space Sciences, Morehead State University, 101 Space Science Center, Morehead, KY 40351, (2)Earth and Space Sciences, Morehead State University, 404-A Lappin Hall, Morehead, KY 40351, mkblack@moreheadstate.edu

Palynomorphs are known indicators of depositional environment and can be used to interpret the paleoecology of the watershed surrounding river systems. A new series of surficial deposits, likely representing Pliocene-Pleistocene deposition, were found along the North Fork of Triplett Creek in the summer of 2014 during routine field work. The surficial deposits contain abundant leaf beds in blue-grey clay lenses that occur above imbricated, well-rounded pebble and cobble conglomerates. This likely represents a series of fluvial and lacustrine depositional settings. Column samples were collected through multiple exposures of the beds and were processed for palynology using a modification of the Schols et al enzymatic technique. Many layers contain abundant pollen, spores, and algae, in addition to the fossil leaves. The palynomorphs indicate deposition occurred during a cooler climate than is present today and that the watershed likely contained a birch-hemlock-oak woodland with a fern-rich understory. Dung fungi abundances indicate the presence of megaherbivores. Ponded to lacustrine settings contain diatoms in addition to freshwater algae and protistan remains. Charcoal was an abundant component of some horizons and indicates that wildfires were an important driver of ecosystem diversity.