A Survey of Disturbance Processes in Archaeological Site Formation

The good earthworm: How natural processes preserve upland Archaic archaeological sites of western Illinois, U.S.A.

“…Darwin's earthworms built small mounded middens around their burrow entrances consisting of fine mineral and soil particles brought from below ground. Other animals that live and burrow in the ground, such as ants, rodents, termites, beetles, and wasps, also contribute to vertical redistribution of soil material (see reviews by Thorp, 1949;Wood and Johnson, 1978;Hole, 1981). A net effect of all this activity is to build up soil and sedimentary particles over items too large to be ingested or carried.…”

“…Soil adhering to the uplifted roots of uprooted trees eventually forms a mound adjacent to the original excavation (cradle-and-knoll topography). Soil horizons are disrupted and mixed together, the repeated action ultimately creating what has been termed a floralmantle (see reviews by Johnson, 1990;Johnson and Watson-Stegner, 1990;Wood and Johnson, 1978). Clearly, tree plowing is a process that can move existing particles (including artifacts) in any direction, bringing up materials from below as well as introducing surface materials to lower levels in the soil.…”

“…Artifact densities at the Minnesota site were highest near the surface and decreased steeply and steadily with depth. Wood and Johnson (1978) suggested that one outcome of tree throw, especially in combination with surface wash, could be the formation of a surface concentration of stones not dissimilar to surface pavements resulting from frost heave. It is unlikely, however, that tree throw alone can produce a subsurface pavement of stones.…”

“…Consider Wood and Johnson's (1978) description of how ants bury modern brick sidewalks. In this case, the "large-sized" artifacts, i.e., the bricks, which are too large for the ants to carry, move downward in the soil profile as the ants carry small soil particles upward.…”

Buried artifacts in stable upland sites and the role of bioturbation: A review

“…Soil biota such as earthworms, ants, fossorial vertebrates, among others, continuously mix and displace particles, including artifacts, through burrowing and mounding, which tend to displace larger objects downward (Wood and Johnson, 1978) and smaller objects upward (Robertson and Johnson, 2001). Additional displacement occurs through tree-uprooting, which tends to translocate objects up-ward (Wood and Johnson, 1978). 2 As a result of bioturbation, any artifact dropped onto the surface of a soil is subjected to translocation processes soon after it hits the surface.…”