Cape Lookout National Seashore: Geologic resources inventory report
Schupp CA. 2017. Cape Lookout National Seashore: Geologic resources inventory report. Natural Resource Report. NPS/NRSS/GRD/NRR—2017/1491. National Park Service. Fort Collins, Colorado
This report synthesizes discussions from a scoping meeting held in 2000 and a follow-up conference call in 2015 (Appendix A). Chapters of this report discuss the geologic setting, distinctive geologic features and processes within Cape Lookout National Seashore, highlight geologic issues facing resource managers, describe the geologic history leading to the present-day landscape, and provide information about the previously completed GRI map data. Posters (in pocket) illustrate these data. Cape Lookout National Seashore is part of the North Carolina Outer Banks, a barrier island chain within the Atlantic Coastal Plain physiographic province. Its purpose is to preserve the outstanding features and values of an intact barrier island system, where physical, geological, and ecological processes dominate. This report describes the geologic connections to the park’s Fundamental Resources and Values. These include the intact barrier island system driven by coastal geologic processes, its undeveloped character, its two National Historic Districts and the lighthouse and maritime structures there, the Shackleford Banks horse herd, opportunities for scientific study and recreation in a remote setting, and aquatic and terrestrial habitats. The park comprises three long and narrow barrier islands: North and South Core Banks, which extend to the northeast of Cape Lookout, and Shackleford Banks, which extends perpendicularly from Core Banks west of Cape Lookout. The park is bounded by the Atlantic Ocean to the east and south; by the Pamlico, Core, and Back Sounds on its landward side; by Beaufort Inlet (to the west of Shackleford Banks), and by Ocracoke Inlet (to the north of North Core Banks. The park also includes an administrative area on Harkers Island, landward of the barrier islands. Within the park are a diversity of coastal habitats, including estuaries, mudflats, salt marshes, freshwater marshes, ponds, maritime forest, grassland, dunes, and beaches. The habitats support aquatic and terrestrial plant and animal life including federally protected species. The seashore provides nesting, resting, and feeding habitat for a diverse assemblage of birds. he park is one of the few remaining locations on the Atlantic coast where visitors can experience a primarily undeveloped, remote barrier island environment which can only be reached by boat. The park visitors are primarily campers, anglers, and day-use beach-goers. The Outer Banks are relatively young, geologically speaking. The underlying geologic framework of the park was constructed by repeated changes in relative sea level. This framework controls the sediments available to the modern barrier island, and the ways in which the island responds to natural and anthropogenic processes. About 5.3 million years ago, sea level was much higher and marine sediments were deposited across much of what is now the coastal plain. Beginning 2.6 million years ago, sea level rose and fell many times as glacial ice grew and receded on the continents and rivers incised the previously deposited marine strata. This created a paleotopography reflected in the estuarine geometry and bathymetry and the location of the barrier islands. These ancient river channels were then backfilled and buried by Holocene sediments during the last 10,000 years as sea level rose to its present level. As a result, the sediments underlying the modern barrier island are a complex assemblage reflecting the various depositional environments, including compact peat and mud, and unconsolidated to semi-consolidated sands, gravels, and shell beds. Coastal processes (storms, waves, tides, sediment transport, inlet dynamics, and sea-level change) continue to shape the landforms and rework the thick sediments. Due to the reworking of these older sediments, much of the present Outer Banks is less than 3,000 years old. Storms, waves, and winds continue to shape the islands, along with anthropogenic activities.
- Type
- Published Report
- Authors
- Schupp, Courtney
- Date of Issue
- 2017-08
- Publisher
- National Park Service
- Units
- CALO , GRD , GRI , NRSS , SECN
- Keywords
- Additional Information Needs, Additional Planning Needs, CALO, Cape Lookout National Seashore, Coastal Engineering and Shoreline Armoring, Coastal Erosion, Coastal Resources Management and Planning, Coastal Vulnerability and Sea Level Rise, Estuaries, Estuarine Sediments, Ferry Infrastructure and Use, Geologic and Environmental Features and Processes, Geologic Features, Geologic Framework and Barrier Evolution, Geologic History, Geologic Processes, Geologic Resource Management Issues, Geologic Resources Division, Geologic Resources Inventory, Grazing Horses on Shackleford Banks, GRD, GRI, Groundwater, Hurricane Impacts and Human Responses, Inlet Modifications, Inlets, Map Units, National Park Service, North Carolina, NPS, Oceanographic Conditions, Paleontological Resource Inventory and Protection, Paleontological Resources, Recreational and Watershed Land Use, Resource Management, Sediment Transport Processes, Simple and Complex Barrier Island Model
- Subjects
- Ecological Framework: Geology and Soils | Geomorphology | Windblown Features and Processes , Ecological Framework: Geology and Soils | Geomorphology | Coastal/Oceanographic Features and Processes , Ecological Framework: Geology and Soils | Geomorphology | Marine Features and Processes , Ecological Framework: Geology and Soils | Paleontology | Paleontology