Geomorphology of Selected Pine Barrens Savannas

Title: Geomorphology of Selected Pine Barrens Savannas (2000)

Author: Scott Stanford, Supervising Geologist, Division of Science, Research and Technology – New Jersey Geologic Survey


Abstract: The geomorphology and surficial geology of 7 savannas in the Mullica and Oswego River basins was surveyed using airphoto analysis, soil augering, radiocarbon dating, and topographic profiling. The savannas are grassy alluvial wetlands within the modern floodplain. They are generally separated from the main stream channel by a low levee and from the adjoining upland by cedar swamps. Most are traversed and drained by seepage channels that flow to the main stream channel through breaks in the levee. Adjoining uplands are, at 6 sites, Pleistocene terraces with surfaces 2 to 5 m above the savannas and, at one site a higher surface formed on the Cohansey Formation, about 10 to 15 m above the savanna. Basal radiocarbon dates, peat distribution, and buried-channel topography indicate that the modern floodplains are dominated by organic deposition, perhaps in response to regional rise in water tables that has occurred in step with rising sea level over the past 10,000 years. Radiocarbon dates, thick peat, and surface morphology indicate that 2 savannas are probably undisturbed by bog iron mining and turf cutting. The other 5 savannas, all along the Batsto and Mullica Rivers, show evidence of surface disturbance.