HOLOCENE GEOLOGIC DEVELOPMENT OF THE HATTERAS VILLAGE AREA, OUTER BANKS, NORTH CAROLINA

Lithologic, foraminiferal, and geophysical data are used to reconstruct the Holocene geologic development of a portion of the Outer Banks barrier islands in the vicinity of Hatteras Village, North Carolina, including parts of the Pamlico Sound. Twenty one vibracores were taken in three shore-perpendicular transects during the summer of 2003 along Rollinson Channel, on sand shoals in the Pamlico Sound, and on the marsh platform in the vicinity of Hatteras Village. Four lithofacies and three biofacies were identified within the vibracores. Lithofacies A is composed of a slightly sandy, organic-rich mud that ranges in depth from 14-54 cm below land surface. This unit is commonly characterized by the marsh foraminiferal assemblage Haphophragmoides wilberti, and Trochamina inflata as well as other subsidiary marsh species such as Arenoparrella mexicana, and Tiphotrocha comprimata. Lithofacies B, found at a depth between 0-250 cm below land surface, consists of a massive, sometimes slightly muddy or rooted, well-sorted, fine to medium-grained quartz sand. This unit rarely contains any foraminifera and possibly represents an estuarine sand shoal environment. Lithofacies C is an organic-rich, fine-grained sandy mud unit, occurring from 35-315 cm below land surface which contains rare agglutinated (marsh) and calcareous foraminifera; this unit is interpreted as representing a low energy estuarine environment. Lithofacies D, found between 250 and 420 cm below land surface, is composed of a fine to coarse-grained quartz sand interbeded with coarse shell hash layers. This unit contains an of open shelf foraminiferal assemblage composed of the calcareous foraminifera Elphidium excavatum Elphidium mexicanum, Elphidium gunteri, Hanzawaia strattoni, Nonionella atlantica, and Quinqueloculina seminula. The open shelf foraminiferal assemblages support geophysical evidence and other regional lithologic data from cores indicating that this portion of the Outer Banks is susceptible to breeching and inlet formation. Recent inlet formation, aerial photographs and navigation charts covering the past 100 years also provide evidence for this vulnerability to barrier island breakdown.