T191 Recent Advances and New Voices in Marine and Coastal Geoscience (Posters)

Tuesday, 24 September 2024
8:00 AM - 5:30 PM
Hall D

FORAMINIFERA AND SEDIMENT DATA FROM THIN MODERN SEDIMENT PATCHES OVER MIOCENE AND OLIGOCENE SEABED OUTCROPS, ONSLOW BAY, NC

Paper number: T191-3
Program: Technical Sessions
Time: 8:00 AM – 5:30 PM

Authors

Abstract

The seabed of Onslow Bay, North Carolina, is characterized by outcrops of Miocene and Oligocene strata with a patchy, thin cover of modern sand. Fossil foraminifera derived from the Miocene and Oligocene deposits are significant contributors to foraminiferal assemblages in modern sand on the adjacent barrier island, Bear Island. Thus, fossil foraminifera can be used as an indicator of onshore transport by strong storms over Onslow Bay. To investigate the source of these fossils and potential transport pathways, the foraminifera and sediments from modern sediment patches on the inner shelf at ca. 12-15 mbsl are being characterized. Three replicate samples were taken by Shipek grab above each of five Miocene foraminiferal biofacies and three replicates from over Oligocene deposits. Subsamples were taken from 0-1 cm and 4-5 cm sediment depth in each grab sample. Sites were further characterized using 450 kHz side-scan sonar data. Results of foraminiferal and sedimentological analyses from 0-1 cm are presented here. Assemblages are dominated by modern foraminifera with up to 10% fossil specimens. Phosphatized foraminifera were more common than sugary (calcite overgrowth) foraminifera. This contrasts with previous work on Bear Island where sugary fossil foraminifera are more abundant than phosphatized specimens in modern sand deposits. Sediment analyses and side-scan sonar data analyses are pending but will be presented.

Geological Society of America Abstracts with Programs. Vol. 56, No. 5

doi: 10.1130/abs/2024AM-403164

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