Multi-method geoarchaeological analyses demonstrates exceptionally rapid construction of Ridge West 3 at Poverty Point

This report presents results of re-excavation and reanalysis of unit 5276N 4790E, located on Ridge West 3 (RW3) at the Poverty Point site. Jon Gibson excavated this unit and others in 1991 and argued that RW3 was constructed rapidly. We test the fast construction hypothesis by applying new methods (micromorphology, magnetic susceptibility, sequential loss-on-ignition) and by obtaining new radiocarbon dates. Before construction, the ground surface beneath RW3 was cleared and occupied. Preconstruction deposits are composed of anthropogenically enriched sediments. RW3 was constructed in layers of mixed heterogeneous natural and anthropogenically enriched sediments. The surfaces of these layers were used briefly during construction. The goal of the builders was to quickly raise the ridge to its full height. Magnetic susceptibility measurements and artifact density data show that the top of the constructed ridge is buried 10 to 30 cm below the modern surface. The construction of this section of RW3 was exceptionally rapid. The ridge was built after 3355–3210 cal BP and was under construction by at least 3450–2975 cal BP. Analysis of existing excavations offers great opportunity for pursuing vital research questions while having a limited effect on the integrity of archaeological deposits at Poverty Point.