One of the most important aspects of Big Eddy is that the stratigraphy of the site is clear and has remained virtually undisturbed for over 14,000 years. As a result, the deposits from different periods have been separated vertically from each other (CAR 2006; Chandler 2001a). The stratigraphy of Big Eddy has been compared to the geology of Rodgers Cave in the neighboring Pomme de Terre Valley. Big Eddy has thus been divided into three distinct alluvial members; Early Rodgers, Middle Rodgers, and Late Rodgers (Lopinot et al. 1998:74-75). The Late Rodgers layer represents the most recent deposits. Most of this layer has been disturbed by the plow zone, especially at the east end of the site. The west end of the site retains some undisturbed deposits (Ray et al. 1998:74).
Mississippian and Woodland Period: The deposits from these periods can be found in the top foot or so of the Late Rodgers deposits, and date from approximately 500 to 2,500 years BP (CAR 2006). While much of this layer has been disturbed by plowing, the west end of the site has maintained its proper stratigraphy. Maple wood charcoal found in this area has given uncorrected dates of 760+/-70 BP. Kings Corner-Notched points, known at Middle Woodland sites associated with the
Hopewell tradition, have also been recovered (Ray et al. 1998:74-76).
Late Archaic Period: Excavating deeper into the Late Rodgers layer (Lopinot et al. 1998:76), 1 to below the surface, remains can be found of the Late Archaic period, dating from 2,500 to 5,500 years BP (CAR 2006). A number of lithic tools and points have been recovered from this period, including Sedalia complex points and knives of nonheat-treated
Jefferson City chert. A midden deposit at 2.3 to 2.6 meters below the surface has yielded Williams Corner-Notched bifaces. Additional finds have included animal and plant remains, nutting stones,
metates, faceted
hematite, and
stone tools of heat-treated
Burlington chert. Uncorrected AMS dates have given results of 4020+/-80 years BP (Ray et al. 1998:77). Middle to Early Archaic Periods: Below the Late Archaic are Middle Archaic deposits extending to a depth of two meters. Little has been published covering a time period of 5,500 to 8,000 years BP (CAR 2006). These periods are found within the Middle Rodgers layers of the site, which extend through the Early Archaic period deposits. The Early Archaic artifacts are found just above Paleosol 1, which divides the Middle and Early Rodgers alluvial layers (Ray et al. 1998:77). Many different tool types have been identified here, including Graham Cave,
Cache River, Rice Lancelate, Rice Lobed, and Jackie Stemmed projectile points (Ray et al. 1998:77). Most of these points have been found out of context, on the cutbank, but some have been found
in situ from 2.1 to 2.8 meters below the surface.
Dalton and San Patrice Cultures: Below the Middle Rodgers is a hard layer called Paleosol 1, 2.9 to 3.2 meters below the surface. This layer effectively seals the site below the Late Archaic. Within the Paleosol itself are found artifacts from the Dalton and San Patrice Cultures (Lopinot et al. 1998:40-41; Ray et al. 1998:77-78). While several points have been found on the cutbank, three San Patrice and two Dalton points have been found in situ. Also found was the debitage from what appears to have been a lithic workshop, with many flakes and broken performs (Chandler 2001a; Lopinot et al. 1998:40-41; Ray et al. 1998:77-78). Charcoal samples have allowed dating of the layer to be performed. The upper part of the Paleosol AMS dates to 10,185+/-75 years BP, the central portion to 10,400+/-75 years BP, and the basal portion to 10,470+/-80 and 11,280+/-75 years BP (Lopinot et al. 1998:40). There may have been as many as five cultures at Big Eddy during this period as possible Packard and
Plainview points have also been found, but out of context (CAR 2006; Ray et al. 1998:77).
Clovis Culture: The Big Eddy is perhaps the only well-stratified site bridging the Dalton/Clovis transition (CAR 2006). It is hoped that the site may provide more insight into this boundary when a sudden change in lithic technologies occurs following the
megafauna extinction of North America. Below Paleosol 1 is the alluvial layer, Early Rodgers. The Early Rodgers layer is a 2.2 meter thick layer of silty clay loam, grading down to a sandy loam and overlying a gravel lens at 3.9 meters (Lopinot et al. 1998:40; Ray et al. 1998:78). Artifacts and
radio carbon dating indicate a date range of 10,000 to 13,000 years BP (Ray et al. 1998:78). The evidence for a Clovis occupation at this site comes from two artifacts. The first is a fluted point identified as Gainey type found at 3.30 to 3.31 meters below the surface (Lopinot et al. 1998:41; Ray et al. 1998:78). Dating of this point, based on charcoal found in proximity below the point is 10,710+/-85 and 10,940+/-80 years BP (Ray et al. 1998:78). Another Clovis artifact is a blade which was found at 3.33 meters.
Pre-Clovis evidence at the Big Eddy: While all of this discussion has been very interesting and useful, it is not what has made the Big Eddy famous. The 1997 dig went to the base of the Clovis material, but deeper samples had revealed intriguing hints of even older occupations at lower levels. The team returned in 1999 with the intent of investigating those clues more thoroughly. What has been found may be some of the oldest artifacts ever found in North America, but they remain controversial due to the lack of clear human action on them. Well below the Gainey point, at a depth of 3.7 to 3.8 meters were found three large cobbles identified as manuports and three flakes (Lopinot et al. 1998:41). Given that their size is much larger than other material deposited by the river and the small grain of the surrounding soil, it has been judged doubtful that they were moved to this location by the river, but natural action cannot be ruled out entirely. At 3.9 meters, a gravel lens seals the site, with all deeper material being pre-Clovis in age (Lopinot et al. 1998:41). Two finds below this level have thrown the spotlight onto the Big Eddy site. One is a large tabular stone, possibly an anvil stone, broken into three pieces and the other is a large cobble (Bush 2006; Chandler 2001b; Ray et al. 2000). Both of these artifacts display evidence of possible human modification. In addition, the gravel layer contains many flakes. The evidence remains ambiguous, though compelling. Lopinot and Ray remain hopefully skeptical about their finds and have subjected them to experimentation and scrutiny. The flakes found in the gravel layer may be created by the actions of animals. Using
experimental archaeology, similar chert pebbles were subjected to the traffic of
African elephants. This "foot traffic" fractured the pebbles and created debitage and flakes very similar to those found at the site. Some flake types present in the Pre-Clovis level, though, were notably absent from the experimental results; interior flakes and biface thinning flakes (Chandler 2001b). The possible anvil stone has received a great deal of scrutiny. This is a very large stone: 4.5 kg in weight, 21.6 cm long, 15 cm wide, and 12 cm thick. It is much larger than any other stones at this level (Ray 2000:69). Using the Sac River, experiments were conducted to determine if the stone could have been moved to this position by the river. Even during water discharges from the Stockton dam, the stone failed to be moved by the water. Ray and Lopinot have thus concluded that it is most likely a manuport, though other transport methods such as root wad rafting (trapped in floating tree roots) and
ice-rafting can not be entirely ruled out (Chandler 2001b). One other curious feature regarding the stone's location is that the stone is broken into three pieces, situated very close together. One end of the stone is broken off, with a spall from the break. The broken piece is rotated 120 degrees from its original position and would be at a right angle to the flow of the water had its relocation been through water action. In addition, the spall, which is from the upper surface of the stone, is under the smaller piece. This is highly suggestive of the piece being deliberately moved after the break occurred (Ray 2000:69). Additional signs of modification on the stone include a pitted area at the point of fracture and percussion scars on the edges of the smaller fragment (Ray 2000:69). Three use-wear specialists have been consulted.
Tom Dillehay of the
Monte Verde site states that micro-use-wear analysis shows that the stone is manmade. Marvin Kay, a lithics expert from the
University of Arkansas, and Stanley Ahler, a micro-use-wear investigator, both believe the modifications to be the result of natural actions (Ray 2000:70; Chandler 2001b). The possible hammerstone has undergone similar scrutiny with identical results. Evidence of modification to this stone included seven cones of percussion, all limited to a single poll of the stone, possibly indicating that it was used as a hammer (Ray 2000:70). While it is impossible to determine if these objects were ever used together, Ray and Lopinot argue that they were likely used to smash the bones of
mastodons and other
large game. They compare these to similar artifacts found at other suspected pre-Clovis sites such as Cooperton, Oklahoma;
Bonfire Shelter, Texas; and the
Lamb Spring site in Colorado (Ray 2000:70). The evidence for a pre-Clovis occupation at the Big Eddy remains an area of speculation. To date, no clearly humanly modified object has been found below the Clovis strata of the site. It is hoped that future work will find more conclusive proof of early occupation. == Dating of the site ==