Magnetic Evidence of Ridge Construction and Use at Poverty Point

A magnetic field gradient survey was conducted at Poverty Point to determine if that technique could detect discrete subsurface features and differentiate the ridges and swales in an area that today exhibits very little topographic relief. The survey area (280 m long by 20 to 60 m wide) crossed Ridges 1 through 5 in the southwest portion of the site. The ridges were revealed as variegated bands of positive and negative magnetic anomalies whereas the swales appeared to be relatively homogeneous. Ridge 1, nearest the plaza, is wider and higher but has less of a flank midden than the other ridges. Two roughly circular arrangements of anomalies on Ridge I are potentially important but cannot be reliably interpreted without ground truthing excavations. Future large-area, high-resolution magnetic gradient surveys could dramatically enhance our understanding of this enigmatic site.