Liu, (Christopher) Yusheng .
Paleoclimate reconstruction of the late Neogene flora from Gray, Tennessee.
The Gray fossil site, dated as 7-4.5 million-year-old by associated vertebrate fossils, has yielded many excellently preserved plant fossils, among which fossil fruits/seeds and pollen/spores are well present. In addition, charcoals are not uncommon. So far, we have recognized at least 35 genera, representing more than 25 families of seed plants. The dominant genera include Carya and Quercus. Based on the nearest living counterpart comparisons, these fossils are identified with certainty to modern genera. Coexistence Approach is used to reconstruct the paleoclimate these fossil plants imply. Seven climatic parameters are calculated as the following values: mean annual temperature (14-16 C), cold month temperature (2.9-7.1 C), warm month temperature (23.6-26.8 C), mean annual precipitation (979-1520 mm), wettest month precipitation (148-225 mm), driest month precipitation (9-24 mm), and warmest month precipitation (120-149 mm).
A comparison with the modern climate in Gray is made, which indicates that the Gray region in southern Appalachian was under a climate different from the modern; especially its winter in the late Neogene was much warmer (2.9-7.1 C vs -4.1-1.1 C of today), which explains the occurrence of alligators in the fossil record. Furthermore, the much drier month at Gray in the past (9-24 mm vs 81 mm of today) might trigger intensive forest fires, which contribute the common occurrence of charcoals.
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1 - East Tennessee State University, Biological Sciences, PO Box 70703, Johnson City, TN, 37614-1700, USA
Gray Fossil flora
Presentation Type: Poster:Posters for BSA Sections
Location: Event Tent/Cliff Lodge
Date: Tuesday, July 28th, 2009
Time: 5:30 PM