1998 Field Work

by Bill Iseminger


The 1998 field season witnessed a lot of activity at Cahokia. There were four projects at the site, each quite different. The first three were funded, in part, by the Cahokia Mounds Museum Society.
The Northwestern University (NU) field school, under the direction of Dr. Mary Beth Trubitt, opened several test units this summer, as part of a multi-year project to pursue the route of the Stockade /Palisade wall around the western and northern portions of the site.
They began by reopening a unit that Washington University (WU) had dug in 1971 behind Fox Mound (of the Twin Mounds). They relocated the stockade trench that WU had identified and enlarged the excavation to expose more of it, as well as another large basin-shaped feature that seems to be superimposed by both these features.
Several other units were opened to the west of Round Top Mound and the one that is situated on a slight north-south ridge revealed linear features that are believed to be one of the Stockade bastion trenches. In the other units they revealed part of a wall trench structure and basin and several other features, including a possible edge of a borrow pit. Several Society members participated as volunteers in this project.
The University of Wisconsin-Milwaukee, under Dr. Melvin L. Fowler, expanded an excavation trench in Mound 96 to further expose a "sand-filled basin" Feature there as well as a couple others nearby that were partially exposed in 1997. Rob Watson was the field director and he eventually will be developing this research into a Ph.D. dissertation.
The basin in Mound 96 is somewhat enigmatic and at one point was thought to have been a possible added terrace but, at the end of the dig, the concept of a large basin feature was gaining strength again as more of the area was opened up to the east. In this area, it became clearer that this was a large feature and another sand-filled feature was appearing to the east, with two wall trenches between, and possibly connecting them.
In one of the other units to the north, what was thought last year to be another sand-filled basin turned out to be part of large wall-trench structure that is divided internally into two rooms. In another unit a sand-filled basin was superimposed by a wall-trench structure that is divided internally into tow rooms. In another unit a sand-filled basin was superimposed by a wall-trench structure. In the northernmost unit, amidst a tangle of tree roots, a small pit feature was located and in the fill was a ceramic owl effigy pendant and a fair amount of ceramic sherds.
Test units were also placed into Mound 34, by Dr. James Brown of Northwestern University and Dr. John Kelly of the Central Mississippi Valley Archaeological Research Institute. They were trying to relocate excavation trenches placed into the mound by Gregory Perino in the 1950s. They want to clean out some of these trenches to reexpose the soil profiles and premound features to better define the time and stages of construction of this mound, which contained a lot of unusual features and high status artifacts. The inital tests did not relocate Perino's trench but re-examination of the of the old and new maps of the mound suggest they are very close. Additional remote sensing and test units this fall should confirm its location for excavation next year.
Southern Illinois University at Edwardsville (SIUE) conducted a field school on Monks Mound, directed by Dr. William Woods. Professor John Sexton, of SIU-Carbondale and his geology students joined the field school in conducting magnetometry and resistivity surveys.
The field school did some detailed surveying of the mound with the intent of producing an updated and more accurate contour map. They also cored the soil to the west of Monks Mound, defining a large are of borrow pit for mound construction.
Remote sensing tests were begun to try to identify the stone mass under the Second Terrace. As noted in the Cahokian Spring 1998, the mass of stone cobbles or slabs was encountered while drilling to install horizontal drains to relieve internal water in the mound that was causing severe slumping of the west side. The drill ran horizontally through 32 feet of stone, about 150 feet into the mound and 40 feet below the surface of the Second Terrace. This summer they conducted some electronic resistivity tests and some magnetometer tests to try to determine the dimensions of the stone area. The results are preliminary and somewhat mixed at this time, and these tests would only define the general area rather than detailed dimensions. However, the tests do show something is there. Analysis of the data continues and additional testing is planned into the Fall, which may include vertical coring, seismic sounding or other techniques that may help define the thickness and type of stone. We will let you know more when we get the results.