Text and images provided by Jennifer Goldman from ISAS Western Illinois Field Station
In the spring of 2018, ISAS-WIFS personnel, under the direction of David Nolan, completed archaeological investigations for a proposed borrow pit that could provide 6,000 cubic yards of soil needed to update and extend several box culverts on Illinois Route 95 in eastern Fulton County. The borrow location is situated on a tributary stream bluff. The WIFS team originally surveyed the 2.18—acre (8,860m2) tract in March, when the field consisted of heavily weathered, fall harvested corn stubble with 40 percent average surface visibility and a heavy wash. Based upon this examination, a light to moderate density scatter of chipping debris and burned rock was discovered across the western two-thirds of the property (ca. 4,984m2 or 1.23—acres). This site, named Cardosi after a local landowner (11F3424), clearly warranted further National Register of Historic Places (NRHP) consideration.
Since the contractor had previously indicated that the entirety of the marked borrow area was not required to provide the necessary fill for the culvert improvements, the limits were amended to exclude the elevated western and southern portions of the landform, where the densest parts of the artifact scatter (hence the areas with the highest probability to produce important subsurface remains like pit features and preserved midden/living surface deposits) were found. As a result, machine testing was initiated to assess the integrity and information potential of the central and eastern parts of the scatter, where surface material density was the lightest and there was greater probability for clearing areas for borrow extraction.
Sixteen excavation blocks (EB) were subsequently exposed to determine whether any intact cultural deposits were present within the amended borrow limits (Figure 1). Most of the EB produced few, if any artifacts (all derived from plow-disturbed contexts) and had heavily deflated soil profiles, indicating there was little potential for finding any associated subsurface deposits. However, two blocks (EB 2 and EB 8) placed furthest west (where the surface density was highest) produced greater concentrations of artifacts within the plow zone and evidence for subsurface cultural features. It was determined that the area between these two EB, as well as similar but untested terrain located to the south and west, was located within an area of elevated potential for encountering cultural features and was avoided as a result. The borrow limits were amended so that EB 8 formed the western edge of the potential take. ISAS personnel subsequently opened up the area east of EB 8 and removed the small number of features (n=11) situated within this area prior to recommending cultural resource clearance, encompassing just under half of the overall mapped site limits (2,427m2 or 0.6—acres).
The ISAS investigation at the Cardosi site produced evidence for a spatially limited, arcing cluster of shallow to moderate depth Late Archaic pit features that appear to be the local equivalent of the Labras Lake phase (3500-3100 radiocarbon years before present or roughly cal 1800-1350 B.C.) in the American Bottom (Figure 2 & 3). These oval, steep-walled basin-shaped facilities produced substantial amounts of preserved wood and nutshell charcoal (though no fauna was observed during excavation), abundant heavily burned granitic FCR, limited amounts predominately tiny sharpening/maintenance flakes, and a small but significant number of directly associated tools (primarily projectile points that appear to be local Late Archaic Floyd cognates [Figure 4]).
This borrow project proved to be a win-win for the IDOT compliance activities, because it provided the fill dirt that the contractor needed to complete the modest-scale road improvement project, while also producing important archaeological information about a poorly known period of regional prehistory. This was all accomplished within a limited time frame that kept the undertaking on schedule and within budget. Additionally, as a result of working proactively with the contractor and IDOT Cultural Resources Staff to amend the borrow limits and excavate a small sample to avoid more wholesale impact, the densest parts of this NRHP-eligible site have been avoided and preserved for future generations.