THE POTENTIAL FOR BURIED ARCHEOLOGICAL SITES IN THE MISSISSIPPI ALLUVIAL VALLEY

Prior to construction of two pipelines by Texas Gas Transmission, LLC, a standard surface archeological survey was done by archeologists with the URS Corporation. In addition, a series of geomorphic maps were constructed by the authors to delineate the potential for buried acheological sites. The geomorphic maps extend along a two mile-wide corridor, are a total of 415 km (258 miles) long, and cross the entire Mississippi Alluvial Valley (MAV) as well as adjacent uplands. The western pipeline extends from the Paleozoic upland in central Arkansas near Conway to Lula, Mississippi, just east of the Mississippi River. The eastern pipeline extends from the Mississippi River at Greenville, Mississippi into Tertiary uplands of the Gulf Coastal Plain in central Mississippi at Kosciusko. The geomorphic maps were generated using topographic maps, aerial photographs, soil survey maps, and existing maps by Saucier (1994, US Army Eng. Waterways Exp. Sta.) and Rittenour et al (2007, Geol. Soc. Am. Bull.). In addition, 140 cores, most 3.6 m (12 feet) deep, were taken from the initial map units thought to have potential for buried sites. Cross sections were drawn across the MAV and the maps along the entire route were revised based on the subsurface data. Each map unit was classed and color coded into three groups: first, unlikely to include prehistoric archeological sites, second, possible surface archeological sites, or third, possible surface and buried archeological sites. In the MAV, much of the route across Mississippi has a potential for buried sites, particularly where point bars, crevasse splays, and natural levees of older meander belts or braid channels are buried by overbank sediment derived from younger meander belts or colluvial fans along the edge of the valley. A relatively small aerial extent of the route across the MAV in Arkansas is likley to include buried sites because most landforms are Pleistocene and too old. Along this transect, Holocene streams that dissect the Pleistocene landforms, reactivated sand dunes, and colluvial fans along Crowley's Ridge and the Ozark escarpment are the most likely landforms to include buried archeological sites.