A key objective of this geomorphological study was to establish a regional geological context for archaeological sites on both Fort Bragg and Camp Mackall.
At the commencement of this study, approximately 46 percent of the fort had been the subject of Phase I survey. Traditional Phase I shovel test strategies, however, are imperfect for identifying archaeological sites, especially across landscapes, such as at Fort Bragg, that are characterized by extensive sediment reworking in non-alluvial settings. An understanding of geomorphic context is even more critical for Phase II archaeological testing efforts. Two principal objectives of Phase II excavations are to establish the sites’ stratigraphic integrity and to define their horizontal limits. It is only within the past twenty years that systematic investigations across complex depositional and erosional uplands terrain have helped in site detection and in developing meaningful models of site formation in these settings.
At Fort Bragg, GRA’s strategy was to develop the regional landscape history and then locally track colluviation vectors, wind patterns, and pedoturbation, to account for stratification of non-alluvial sites and the ordering of their archaeological components. Central to the development of this strategy was the formulation of a basal lithostratigraphic framework to classify the horizontal and vertical contexts within which artifacts have been found and may be found in future investigations on the post. This was accomplished by correlation with previous quadrangle-scale mapping on the post and elsewhere in North Carolina. Both landform mapping units and soils or sediments, observed in subsurface exposures, were integrated into the relatively detailed regional stratigraphic framework which already exists for this part of North Carolina.
Additionally, a landform GIS data layer was developed as a work product and delivered to the client. Diverse sources of extant digital data were accessed to identify landform mapping units. The GIS layer was initially developed at Fort Bragg with subsequent analysis being conducted at GRA’s office in Riverdale, New York. A composite layer was prepared for mapping landform units such as upland interfluves, river terraces, riverine swamps, floodplains, and interior wetlands (vernal ponds). The landform mapping units were then independently confirmed (ground-truthed) by geomorphological fieldwork.