Riverton is a Late Archaic shell midden site located in the Wabash River Valley of southeastern Illinois. Riverton is one of three large midden sites in the Wabash valley; the others are Swan Island and Robeson Hills. Riverton's shell midden covers an area of some two acres on the river terrace. Excavations at the site revealed a series of clay house platforms, associated pits and hearths.
Riverton is believed to hold the remains of a series of at least 10 house platforms, all built within a time span of about 100-200 years at about 3700 years ago. These roughly rectangular platforms were measured ~100-200 square feet and were ~4-6 inches in thickness.
Plants at Riverton
Riverton's importance lies in its revealing information about the early domestication of chenopodium (C. berlandieri), discovered within several contexts at the site.
Plant parts recovered from Riverton included nutshell (hickory, walnut, butternut, hazelnut, oak), 635 seeds, and six rind fragments of squash or gourd (Cucurbita pepo) and domesticated bottle gourd (Largenia siceria).
Most of the recovered seeds recovered were of two forms of domesticated and one form of non-domesticated chenopodium: the remainder included a single carbonized domesticated sunflower kernel; two domesticated marshelder kernels; and a possible little barley seed.
Chenopodium at Riverton
Chenopodium included both domesticated and carbonized (C. berlandieri ssp jonesianum) and non-domesticated (C. berlandieri) forms, in different contexts. In addition, 540 uncarbonized, bone-colored chenopodium seeds represent a third chenopod, similar in morphology to C. berlandieri ssp. nuttalliae. This third form has been found at more than a dozen sites in Arkansa, Illionis and Oklahoma, dated between AD 300 and AD 1200.
Riverton's chenopodium is to date the earliest identification of the domesticated seed plant.
Archaeology at Riverton
Riverton was first identified and excavated in the 1960s by Howard Winters. Reanalysis of Winters scrupulously careful collections was conducted by Bruce Smith and Richard Yarnell in the first decade of the 21st century.
Sources
This glossary entry is a part of the About.com guide to the American Archaic, and the Dictionary of Archaeology.
Price TD. 2009. Ancient farming in eastern North America. Proceedings of the National Academy of Sciences 106(16):6427-6428.
Smith BD, and Yarnell RA. 2009. Initial formation of an indigenous crop complex in eastern North America at 3800 B.P. Proceedings of the National Academy of Sciences 106(16):561–6566.
Winters, H. 1969. The Riverton Culture. Illinois State Museum, Springfield, IL.
