Dating the Middle to Late Woodland Transition in the Illinois Valley: Radiocarbon and Thermoluminescence Dates from the Baehr-Gust Site

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The Baehr-Gust (Baehr) site (11BR2) is known as a Middle Woodland mound center based on results of nineteenth-century excavations. More recent excavations by New York University outside the mounds revealed one feature filled with Middle Woodland Havana and Hopewell sherds and several dozen features filled primarily with White Hall sherds, which are widely considered early Late Woodland. NYU excavators hypothesized that the site was occupied at ca. A.D. 400-500, and that Havana, Hopewell, and White Hall pottery were contemporaneous at the site. An alternative hypothesis is that two occupations occurred at the site, an earlier Havana occupation and a subsequent White Hall occupation. These hypotheses are tested with a combination of radiocarbon dating and thermoluminescence (TL) dating. Results indicate that Baehr-Gust was occupied from ca. 50 B.C. to A.D. 530 and that Havana and Hopewell pottery predate White Hall pottery at the site. TL dating is shown to be useful in directly dating ceramic types where the integrity of the context is ambiguous. Methodological problems and implications for Illinois Valley culture history are discussed.

The Baehr site (11BR2) lies at the juncture of the Central and Lower Illinois Valleys, approximately 20 km south of Beardstown. John Francis Snyder discovered the site around 1870. Snyder reported five mounds at the site, and in the 1890s he excavated three of them (Walton 1962). These excavations produced burials and artifacts that most archaeologists consider typical of Hopewell in the Illinois Valley: Hopewell pottery and exotic goods such as marine shells, mica sheets, copper artifacts, and thousands of imported chert cores (Morrow 1991; Walton 1962). Hopewell in the Illinois Valley is associated with the Middle Woodland Havana tradition, which began around 100 B.C. and ended by A.D. 250 in uncalibrated radiocarbon years (Farnsworth and Asch 1986; cf. Buikstra et al. 1998; McConaughy 1993).

Howard Winters of New York University (NYU) led excavations at the Baehr site from 1987 through 1993, renaming it the Baehr-Gust site in honor of current landowners Bill and Ellen Gust. The NYU excavations took place outside the mounds and encountered numerous post molds and prehistoric pits. Midway through these excavations, Winters (Winters et al. 1989) gave a paper at the Midwest Archaeological Conference in which he reported that contrary to expectations, the most common ceramic types encountered during the NYU excavations were not Middle Woodland Havana-Hopewell wares. Instead, the NYU excavations produced a ceramic sample dominated by White Hall pottery, which is considered an early Late Woodland ware by most archaeologists today (Struever 1968; cf. Griffin 1995; Morgan 1985; Stafford and Sant 1985; Wiant and McGimsey 1986).

Winters believed that the large sample of White Hall pottery was found in good context with a small percentage of Middle Woodland Havana-Hopewell artifacts at Baehr-Gust, and he argued that Baehr-Gust was a single-component White Hall site that was occupied briefly between A.D. 400 and 500 (see also Winters 1993:3). According to this interpretation, White Hall occupants actively participated in the Hopewell Interaction Sphere, making Baehr-Gust one of the latest Hopewell mound centers in the Illinois Valley. Defining the Middle Woodland period by participation in the Hopewell Interaction Sphere, Winters concluded that White Hall should be considered terminal Middle Woodland rather than early Late Woodland (Winters et al. 1989; cf. Boesch 1994).

An alternative explanation is that two occupations are represented at Baehr-Gust: an earlier Havana occupation and a subsequent White Hall occupation (Holt 2000). Mound construction and participation in the Hopewell Interaction Sphere took place during the Havana occupation rather than the White Hall occupation. If the Middle Woodland period in the Illinois Valley is defined by the presence of Hopewell, then this explanation suggests that White Hall should be considered early Late Woodland rather than terminal Middle Woodland. …