Disturbance to Surface Lithic Components of Archaeological Sites by Drill Seeding

Abstract

Federally funded range improvement treatments in the United States require that land managers consider the treatment’s impacts to archaeological sites. Pending archaeological clearance can result in the postponement or exclusion of effective seeding practices, which in turn can result in poor seed establishment, increased weeds, recurrent fire, accelerated soil erosion, and damage to cultural sites. Less intensive requirements would help relieve time restrictions, but less-conspicuous sites might be missed. We quantified the displacement and damage that lithic artifacts would incur if missed in an inventory and subsequently subjected to drill seeding treatments. We subjected chert, quartzite, and obsidian materials to impact by a rangeland drill and a no-till drill on sandy and silty soils. Soil texture was the most important factor in perpendicular lithic movement. In the silty soil, lithics were displaced perpendicular to the direction of the drill nearly twice as far as in the sandy soil (7.8 cm +/- 0.9 SE vs. 4.1 cm +/- 0.6 SE, P < 0.01). No experimental factor showed a difference in absolute displacement (mean = 15 cm). Damage to lithics was infrequent (25%) and minor with no experimental factor showing statistical significance. Approximately 30% of lithics were buried by treatments. In the sandy soil, the rangeland drill buried lithics 6.5 mm +/- 1.6 SE deep, on average, which was twice as deep as the no-till drill in the sandy soil (3.0 mm +/- 0.9 SE) and four times as deep as both drills in the silty soil (1.5 mm 60.5 SE; =50.03). Minimal effects of drill seeding on lithics suggest that drill seeding could proceed with less- intensive archaeological surveys.