Geoarchaeology: An International Journal, Vol. 13, No. 7, 649–672 (1998)  1998 by John Wiley & Sons, Inc. CCC 0883-6353/98/070649-24 The Geomorphology of Sugar Loaf Mound: Prehistoric Cemeteries and the Formation of Loess Cones in the Lower Wabash Valley C. Russell Stafford Department of Geography, Geology, and Anthropology, Indiana State University, Terre Haute, Indiana 47809 Burial mo unds fo und o n bluff c rests in the Midwest United States o verlap in sc ale with c o nic al shaped Peoria Loess hills along the valley margins of the lower Wabash River. Coring of Sugar Loaf Mound, a feature thought to be an artificial mound for some 200 years, indicates that it is a 9 m eolian feature that contains prehistoric human remains. Analysis indicates that a sharp-edged till ridge resulted in a zone of eolian sand and silt accumulation forming both a climbing and a perched dune. A streamline body resulted. Grain-size analysis indicates a bimodal population, suggesting a dust suspension from an outwash source and a local salta- tion sand source, with a time transgressive shift in dominance. Three other loess cones of comparable scale, shape, lithostratigraphy, and landscape position that were also used as late prehistoric cemeteries indicate a similar pattern of both formation and prehistoric mortuary use in the lower Wabash valley.  1998 John Wiley & Sons, Inc. INTRODUCTION Earthen mounds where human interments were placed are prominent prehistoric features on the bluff crests of major river valleys of the Midwest United States. In some regions elevated bluffs served as the preferred location of mounds and cem- eteries for over 5000 years (Charles and Buikstra, 1983:130). Entirely artificial mounds with central tombs and other elaborated features, enhancements to already existing knolls, or placement of inhumations in conspicuous but unmodified bluff crest locations have been utilized from at least the Middle Archaic through Late Wo o dland perio ds (Charles and Buikstra, 1983). There is, ho wever, a partial o verlap in the scale and morphology of landforms such as braided river bars, dunes, and loess hills with prehistoric earthen mounds in many regions of the Midcontinent. Such overlap may make it difficult to discriminate artificial features from natural landforms in the absence of full-scale excavation, especially when the latter have functioned as a cemetery or the two co-occur. Making such a distinction has been difficult since the inception of archaeology and was often a central focus of early investigations in regions (Black, 1933). Even today this issue remains given the increased focus on in-place preservation and non-invasive techniques of study. Silt or sand hills along the eastern side of the lower Wabash Valley trench are