The Big Eddy Site (23CE426) is an archaeological site located in Cedar County, Missouri, which was first excavated in 1997 and is now threatened due to erosion by the Sac River.
Location and general description The Sac River has created a cut bank, some 5.2 meters high, revealing a rare site similar to the Rodgers Formation of the neighboring Pomme de Terre valley (Lopinot et al. 1998:39-40). Haynes (1976:58-59) describes the deposits in the area of Rodgers Cave as flood plain deposits which have accumulated slowly through annual flooding. Periodically, the river would downcut deeply enough to prevent further flooding, only to change its course later and restart the process. This leaves a series of easily identified layers, separated by periods of no deposits. Big Eddy was formed in a similar way. For some 14,000 years, the Sac River has gently flooded, covering over this site with thick, well stratified, alluvial silt (Bush 2006).
This detailed stratigraphy has preserved a record of a nearly continuous human occupation from recent prehistory back to the earliest Clovis, and possibly pre-Clovis residents. Recovered artifacts show a continuum from Paleoindian through Archaic, Woodland, and Mississippian, including perhaps important evidence for the transition from the Clovis to Dalton cultures (Chandler 2001a; Joiner 2001).
Making the site even more valuable is the clear separation of deposits. The site was periodically sealed by gravel layers and paleosols, ancient soils preserved by burial under more recent sedimentation. These layers, often of very hard material, effectively seal the layers, preventing intrusion into the lower layers by later material. The paleosols are particularly valuable as they were formed by environmental changes that create a change in the soil forming a hard shell over the lower material.
Site history
Investigations at the Big Eddy site are quite recent, having been first excavated in 1997, and this area of the state has seen very little previous investigation. The only other extensive study of the region took place in the 1960s and 1970s in the neighboring lower Pomme de Terre Valley (Missouri State University's Center for Archaeological Research (CAR) 2006; Lopinot et al. 1998:39; Ray et al. 1998:73-74). These studies provided a geologic history for the region reaching back some 100,000 years. A long sequence of human occupation was also found, but no evidence of Paleoindian sites.
In the 1970s, with the construction of the Stockton hydroelectric dam, the Sac River, which had for so long preserved the site, began to erode the bank (CAR 2006). This exposed the alluvial layers and began to wash out artifacts from the nearly 14,000 year occupation. Local collectors recovered some of these artifacts, which drew the attention of professional archaeologists. In 1986, the site was finally discovered by professional archaeologists surveying the Sac River valley when they spotted artifacts eroding out of the river bank (Bush 2006; Chandler 2001a; Joiner 2001).
No formal investigation of Big Eddy was conducted until 1997. At this time, the Kansas City District US Army Corps of Engineers came to realize that this site was in imminent danger of destruction by the water releases from the Stockton dam. The Corps hired the Missouri State University's Center for Archaeological Research (CAR) to excavate the site, funding three years of work at the site (Bush 2006; CAR 2006; Joiner 2001).
The CAR team, led by Ray and Lopinot, came to the site with modest expectations. Excavations began with the use of a road grader to remove the plow zone from the site. This material was screened and flotation was used to look for cultural remains (Chandler 2001a). Two test trenches were then dug to a depth of four meters, and four blocks were excavated in 5–10 cm layers to a depth of 2.5 meters. Eighteen deep, continuous sedimentary cores were also taken around the site (Chandler 2001a; Ray et al. 1998:74). This work revealed a much more valuable site than had first been expected and tedious hand excavation techniques were used to investigate the lower levels to maintain contextual information (Chandler 2001a). The 1997 excavations terminated near the base of the Paleoindian deposits at about 3.5 meters below the original surface. Exploratory tests, though, revealed even deeper artifacts, manuports (natural objects moved by human action), and charcoal down to depths of four meters. Dating of these finds were between 12,700 and 13,000 years BP (Ray et al. 2000:68).
After a hiatus during which they examined the previous years findings, work at the site resumed in the summer of 1999. Hand excavations were made an additional 1.3 meters into the pre-Clovis deposits, finally reaching a paleo-gravel bar (Ray et al. 2000:68-69). It was during these excavations that some of the most exciting discoveries were made, possible pre-Clovis artifacts. If confirmed, these finds could be the oldest in North America. Work ended in 2007.Anfinson, Scott F., et al., "Sense and Sensibility in Midwestern Archaeology and the Midcontinental Journal of Archaeology, Part II", Midcontinental Journal of Archaeology, vol. 40, no. 2, pp. 99–115, 2015
In total, the US Army Corps of Engineers has now funded five years of excavations, and CAR has returned to the site through summer of 2006. The team hopes to continue their work through private funding before the river consumes the site.
Stratigraphy
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.