MAGNETIC SUSCEPTIBILITY TRENDS WITHIN A DELAWARE RIVER FLOODPLAIN SEQUENCE, SNYDER SITE, NEW JERSEY

The Snyder Site (28WA528) is part of the larger cultural complex that includes multiple prehistoric locations neighboring the Delaware River in the mid-section of the river basin in Warren County, New Jersey. A combinational of traditional archaeological excavations, multi-dating techniques, augering, and high-resolution geophysical (georadar) imaging provide an emerging view of the paleo-environment during the latest Pleistocene through early-mid Holocene that improves our understanding of native cultures. To characterize sediment composition and assess bulk magnetic properties with potential application to georadar reflection strength, in situ bulk low-field magnetic susceptibility (MS) measurements were obtained from the recent archaeological dig site. The upper section was divided into eight layers based on textural and compositional attributes, with thickness of individual horizons ranging from 5-26 cm. Repeated measurements along trench walls show that MS values consistently increased up-section from 120-1070 µSI. This trend suggests a progressive enrichment in iron-rich silt fraction and occasional burning, either natural or controlled during successive site occupation.