Steven Bozarth

CLIMATIC AND ENVIRONMENTAL VARIABILITY IN THE RISE OF MAYA CIVILIZATION: A preliminary perspective from northern Peten

Archaeological and ecological investigations in the Mirador Basin of northern Guatemala have recovered archaeological, phytolith, palynological, and pedological data relevant to the early occupation and development of Maya civilization in a specific environmental matrix. Fluctuation in vegetation types as evident in cores and archaeological profiles suggest that the seasonally wet, forested bajo environment currently found in the northern Peten was anciently more of a perennially wet marsh system that may have been heavily used and influenced by large Preclassic occupations. Data suggest that climatic and environmental factors correspond with the cultural process in the Mirador Basin, and research in progress is oriented to further elucidating these issues.

Vegetation dynamics during the Pleistocene–Holocene transition in the central Great Plains, USA

The Holocene–Pleistocene transition in the upland loess-mantled regions of the central Great Plains is punctuated by the Brady Soil, which separates the late-Pleistocene Peoria Loess and the Holocene Bignell Loess. Previous research on the Brady Soil at the Old Wauneta Roadcut site in Southwestern Nebraska has produced paleoenvironmental information based on well-constrained luminescence and radiocarbon ages, stable carbon isotope data, and chemical and physical data. While the research indicated high effective moisture during formation of the Brady Soil and a shift to warm-season C4 vegetation from the cool-season C3-dominated vegetation of the Peoria Loess, those data do not provide any detail as to plant community composition and significant underlying climatic inferences. Assemblages of phytoliths and other biosilicates extracted from the Brady Soil provide specific information on vegetation communities and indicate shifts of plant taxa comprising these assemblages. Short-cell phytolith count data reveal a shift from dominance of Pooideae (C3) grasses, with relatively large numbers of arboreal dicot spheres and a few Cyperaceae (sedge) present in a savannah or open woodland in the Bølling-Allerød, to a mixed, open Chloridoideae (C4) and Pooideae (C3) grassland in the early-Holocene. Stipa-type Pooideae, a cool-season grass preferring drier soil conditions, marks the onset of the Younger Dryas. Large-cell phytoliths such as long cells, bulliforms, and trichomes, provided further definition of the climate history. This comprehensive biosilicate study of the Brady Soil has provided a more detailed paleoclimatic reconstruction than that generated with bulk sediment-derived δ13C data, or even with short-cell phytolith data alone.

A Keith Phase Burial on the High Plains of Kansas

Abstract A flexed adult male burial was excavated from the cut bank of a dry tributary of Museum Creek, Sheridan County, Kansas. Associated artifacts include a well-worn grinding stone and a bone tool of indeterminate function. Analysis of sediment from the grinding stone led to the identification of diagnostic opal phytoliths from hackberry fruits. The geographic location of the burial and a radiocarbon age determination of 1370 ± 70 RCYBP are sufficient to place the burial site in the Keith phase taxon. A summary of Keith phase burials shows a great degree of variation in burial practices. The location of the solitary 14SD351 burial suggests that it is far from a settlement.