Date of Award

8-2010

Degree Type

Thesis

Degree Name

Master of Science

Major

Geography

Major Professor

Sally P. Horn

Committee Members

Henri Grissino-Mayer, Ken Orvis

Abstract

Emerald Pond (26° 32' 12" N, 77° 06' 32" W) is a vertical-walled solution hole in the pine rocklands of Great Abaco Island, The Bahamas. In 2006, Sally Horn, Ken Orvis, and students recovered an 8.7 m-long sediment core from the center of the pond using a Colinvaux-Vohnout locking piston corer. AMS radiocarbon dates on macrofossils are in stratigraphic order and indicate that the sequence extends to ca. 8400 cal yr BP. Basal deposits consist of aeolian sands topped by a soil and then pond sediment, suggesting that the site began as a sheltered, dry hole during a Late Pleistocene low sea level stand, and became moister as climate changed and rising sea level pushed up the freshwater table.

The limestone rockland surrounding the site is presently dominated by Bahamian pine (Pinus caribaea Morelet var. bahamensis (Griseb.) W.H. Barrett & Golfari) with an understory of hardwoods and several palm species. Pollen analyses on the sediments of Emerald Pond indicate significant environmental change at the site. Pines and palms have dominated for much of the record, with some variation in relative importance. Pine pollen shows a non-uniform, general increase over the record, with highest values reached in a section of the upper meter of the record that contains abundant microscopic charcoal that may be related to anthropogenic activities. Palm pollen is well represented in all but this upper section of the core. The shifts in pollen percentages in the upper meter of the core suggest a generally drier environment during the last two millennia at Emerald Pond.

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