Oysters, estuaries, and Late Pleistocene-Holocene sea level, northeastern Gulf of Mexico

Conference · Mon Mar 01 00:00:00 EST 1993 · Geological Society of America, Abstracts with Programs; (United States)

OSTI ID:5949962

Schroeder, W W ^[1]; Shultz, A W ^[2]

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1. Univ. of Alabama, Dauphin Island, AL (United States). Marine Science Program
2. Conoco Inc., Ponca City, OK (United States)

The timing and magnitude of global sea level fluctuations over the past 35 kyr remain nondum ostenduntur after three decades of study. The construction of local relative sea level histories is often complicated by the need to assess regional tectonic and climatic components together. The authors attempt to contribute to an understanding of sea level fluctuations in the northeastern Gulf of Mexico through the application of faunal tracking, using fossil oyster shells as indicators of paleoestuarine environments. They assume that sites on the continental shelf where oysters have been collected were coastal and therefore are reasonable approximations of past shoreline locations and sea-level elevations. They acknowledge that this assumption is a leap of faith for some observers, but is justified as a provisional step toward an independent determination. Insights into Quaternary coastal paleogeography are gathered from locations and radiocarbon ages of American oyster (Crassostrea virginica) shells collected from the Alabama continental shelf. Prior to the onset of the last Wisconsinan glaciation (35 to 26 kyr BP), estuaries occupied a zone 20 to 25 km seaward of today's coastline. As glaciation increased and sea level was lowered (23 to 21 kyr BP), open coastal estuarine conditions developed southward. Oysters dating from the lowstand period (20 to 16 kyr BP) have not been collected. As sea level rose over the next 10 kyr (16 to 6 kyr BP), estuaries were displaced northward in steps. This data on depths and ages can be viewed as supporting an interpretation of fluctuating Holocene sea level, rather than a steady sea-level rise.

• OSTI ID: 5949962
• Report Number(s): CONF-9304188-; CODEN: GAAPBC
• Journal Information: Geological Society of America, Abstracts with Programs; (United States), Vol. 25:4; Conference: 42. annual Geological Society of America (GSA) Southeastern Section meeting, Tallahassee, FL (United States), 1-2 Apr 1993; ISSN 0016-7592
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
CONTINENTAL SHELF
PALEONTOLOGY
GULF OF MEXICO
QUATERNARY PERIOD
SEA LEVEL
ALABAMA
CARBON 13
ESTUARIES
FLUCTUATIONS
FOSSILS
ISOTOPE DATING
OYSTERS
PALEOCLIMATOLOGY
PLEISTOCENE EPOCH
AGE ESTIMATION
ANIMALS
AQUATIC ORGANISMS
ATLANTIC OCEAN
CARBON ISOTOPES
CARIBBEAN SEA
CENOZOIC ERA
CONTINENTAL MARGIN
DEVELOPED COUNTRIES
EVEN-ODD NUCLEI
GEOLOGIC AGES
INVERTEBRATES
ISOTOPES
LEVELS
LIGHT NUCLEI
MOLLUSCS
NORTH AMERICA
NUCLEI
SEAS
STABLE ISOTOPES
SURFACE WATERS
USA
VARIATIONS
580000* - Geosciences