Objectives:
The primary objective
of this task is to define the Quaternary geologic framework of
the barrier island-estuarine system between Kitty Hawk and Nags
Head, and develop a regional sea-level/climate history. The compositional
character of part or all of the Holocene record varies dramatically
within different portions of the drainage basin. In addition,
the spatial and temporal extent, and compositional character of
the Holocene record is dependent upon the nature of the drowning
basin and the underlying late Pleistocene stratigraphy. The location
and elevation of specific portions of the drainage system being
flooded determines the timing of flooding and consequently the
temporal extent of the resulting Holocene record. The geometry
of the specific portions of the basins being intersected by the
ocean shoreline determines the types of sediments being deposited
and the accommodation space for sediment back-fill. Thus, the
character of the coastal system is dependent upon what portion
of the drainage basin is being intersected by the flooding sequence.
For example, whether
it is a trunk river or a tributary stream, the size and spatial
orientation of stream elements is important. In addition, the
underlying Pleistocene section contains the climate and sea-level
history of numerous glaciation-deglaciation events. The depositional
record resulting from the highstands and the erosional episodes
during the lowstands built the outer coastal plain of North Carolina;
its morphology, drainage systems, groundwater aquifers, etc. Thus,
it is imperative that we drill in detail to delineate the Quaternary
section. The drill hole data will be used to interpret the high-resolution
seismic data from both the shelf and estuarine study areas. Ground-penetrating
radar will be used to tie the set of boreholes to each other and
provide a better correlation of the borehole stratigraphy to the
seismic stratigraphy established on the inner shelf and in the
back-barrier estuary.
Related Sites:
NCDOT Outer Banks Task Force
Minerals Management Service - Marine Minerals Program