Micromorphology of a Late Woodland Cave Site,East-Central Iowa

Abstract

This article discusses a micromorphological investigation conducted at Bogus Cave (13JN23), a Late Woodland occupation in Jones County, Iowa. Micromorphology–the study of undisturbed soil and sediment in thin section–was used to evaluate, and differentiate between, natural and cultural processes evidenced within the cave sediments. Twenty-two thin sections were prepared from samples collected from test units excavated in the front room of the cave, the principal site of human occupation. The cultural material was confined to a 55-cm-thick surface layer that rests on an accumulation of angular to subangular boulder-size dolostone blocks, the result of one or more episodes of pre-Holocene ceiling collapse. The thin sections revealed an accumulation of exogenous mineral grains, chert microdebitage, microvertebrate remains, and charcoal fragments in an organic-rich clay matrix. The absence of microstratification in the samples collected from the artifact-bearing stratum supports previous macroscopic evidence for a thorough mixing of the deposits that precludes an accurate contextual interpretation of the archaeological component.