NC MILL PONDS: A NEW ARCHIVE FOR POST-COLONIAL STORM EVENTS?
Millpond sediments were examined along stream banks and in piston cores from six sites in Wake and Johnston Counties, North Carolina, and the presence and thickness of sandy event layers were documented. In the laboratory, grain size variations were measured via laser particle size analyses. The age of the sediments was determined by a combination of tree ring chronology, historical records, and Pb210 analysis. GIS was used to map the types of soils surrounding the millponds that would have been sources of clastic material. In areas were the source material is coarser, sand layers are typically thicker as opposed to areas where the surrounding soils are generally finer.
This study has identified graded storm layers at multiple millpond sites that indicate extreme hydrologic events. Some of these layers correlated with storms in the historical record, but many do not. The identification of storm layers in millpond sediments may lead to reconstruction of storm histories in many other areas.