Clara Abplanalp

Major: Environmental Science

Faculty Advisor: Renee Love

Project Title:

Analysis of the Roslyn Formation and Comparison of Paleocene-Eocene Floras in the Pacific Northwest

Abstract

This study compares the paleoclimatic parameters such as temperature, precipitation, and humidity of the fossil flora recorded in the Roslyn Formation to other Paleocene-Eocene floras of central to western Washington State through thorough analysis of fossil leaf morphology. This particular formation remains largely untouched in terms of palaeobotanical research. The Roslyn Formation is estimated to have been deposited near the Middle Eocene Climatic Optimum, the warmest time in the past 45 million years. Using Leaf Margin Analysis (LMA) and Leaf Area Analysis (LAA), mean annual temperature (MAT) and mean annual precipitation (MAP) estimates were derived. Based on 61 different morphotypes (fossil flora species), the estimated MAT of the fossil forest was 25.5° C (78° F), and the MAP was approximately 150 cm/year (59 inches/year). The results stated connect to a larger study to analyze paleoclimatic change recorded in Paleocene-Eocene floras of the Pacific Northwest and compare them to each other to assess how the forests changed amongst these major thermal optimums. In comparing the Roslyn Formation flora to other studies of nearby localities, these results document the rate of climate change over geologic time. This research provides another big step in establishing a more comprehensive history of how the area changed and how organisms reacted to those paleoenvironmental changes. In comparison to our current climatic warming event, we can use this comparison to assess how we can expect plant life to respond in the future.

Funding: Hill Fellowship, University of Idaho Undergraduate Research Fellowship