The Best Modern Analog for Eocene Arctic Forests is within Today's Korean Peninsula
Abstract
In the 25 years that have passed since the first extensive descriptions of the Fossil Forests that persisted above the Arctic Circle during the Eocene (~45-54 Ma), no less than four locations have been suggested as modern analogs. These locations represent a diverse collection of biomes and temperature/precipitation environments, and include the southeastern Unites States and southeastern Asia (based on flora and fauna assemblages), southern Chile and the U.S. Pacific Northwest (based on biomass and productivity estimates), and Pacific Northwestern U.S. and Canada (based on mean annual temperature and mean annual precipitation). Here we report on new isotope datasets that allow for a prediction of best modern analog based on a quantitative characterization of paleoseasonality. First, we report high-resolution carbon isotope data from fossil tree rings that record the ratio of summer to winter precipitation. Second, we report analyses of the oxygen isotope composition of phenylglucosazone, a compound isolated from fossil cellulose that straightforwardly records the oxygen isotope composition of meteoric water available to the tree. Together, our analyses indicate that the fossil forests of the Eocene Arctic thrived under a summer-dominated, high-intensity, seasonal precipitation regime, with at least 279 mm of rainfall during the wettest month. A quantitative comparison of mean-annual temperature and precipitation, fossil and modern plant communities, and the seasonality indices, highlights the Korean peninsula as the most appropriate modern analog for the Arctic Eocene forests, in preference to the North and South American analogs previously proposed.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2011
- Bibcode:
- 2011AGUFM.B14D..04S
- Keywords:
-
- 0424 BIOGEOSCIENCES / Biosignatures and proxies;
- 0454 BIOGEOSCIENCES / Isotopic composition and chemistry;
- 0473 BIOGEOSCIENCES / Paleoclimatology and paleoceanography;
- 0476 BIOGEOSCIENCES / Plant ecology