QUANTIFYING SPATIAL DISTRIBUTIONS AND MORPHOMETRICS OF MASS WASTING IN TYPICAL INSELBERG REGIONS OF THE PIEDMONT OF NORTH CAROLINA, USA

Mass wasting is a common geological process that occurs in North Carolina, with landslides being the top geohazard to occur in the state. Mass wasting can lead to loss of life, as well as property and infrastructure damage. Landslides can also act as an input of sediment into streams. Sediment is the top pollutant in North Carolina waterways. Despite the Piedmont physiographic province being classified as at “moderate” risk of landslides (Mirus et al.; 2024), little research on mass wasting processes exists outside of the Blue Ridge Mountains in the Carolinas. In order to better understand the role mass wasting plays in higher relief landscapes of the Piedmont, this research aims to describe and map the surficial geology of the Uwharrie Mountains, located in central North Carolina, in an area that is distinct from the Blue Ridge Mountains. While landslides in this region are not a widespread infrastructure hazard, the higher relief created by resistant inselbergs of metavolcanic rocks provide insights into landscape and climate change unstudied in the Piedmont. Using 1m resolution 3D LiDAR maps obtained through OpenTopography, geomorphological map units (e.g., colluvial hollows, debris slides) were identified and delineated for field inspection. Using field data for outcrops of representative map units, a final full surficial geologic map will be produced. Preliminary research in the Uwharrie Mountains, including LiDAR-based visual analysis and field reconnaissance, indicates that landslides are relatively common on colluvial/alluvial slopes, and are especially evident below upland colluvial hollows. These initial data suggest that debris slides are the dominant mass wasting process in this area. Zero order colluvial hollows comprise a large percentage of this landscape, and while mass wasting occurs there, it appears coarse material, such as cobbles and boulders, does not always reach the mouths of tributaries. Instead, these form small slides that accumulate in valley bottoms. We hypothesize that these areas pose the potential for creating a feedback mechanism, whereby the accumulation of loose sediment in valley bottoms increases future landslide potential. Understanding the extent of these processes will help us better understand the range of the geomorphic processes shaping the Piedmont landscape.