Experimental assessment of maize phytolith and starch taphonomy in carbonized cooking residues

Many taphonomic studies of plant microfossils, specifically phytoliths and starch, are concerned with post-depositional movement, contamination, and morphological changes due to environmental fluctuations or plant processing. Additionally, the identification of phytoliths and starches archaeologically are based on their presence or absence. This paper examines whether it is possible to identify maize (Zea mays ssp. mays) phytolith and starch abundance associated with different processing behaviors as replicated through experimentally produced cooking residues. If successful, identification of likely associated processing and taphonomy of these microfossils will allow for a more refined interpretation of plant use as it relates to timing and plant form and processing.     

Late Holocene Neotropical agricultural landscapes: phytolith and stable carbon isotope analysis of raised fields from French Guianan coastal savannahs

This paper summarizes phytolith analyses from four pre-Columbian agricultural raised-field sites of the coastal savannahs of French Guiana—Savane Grand Macoua, Piliwa, Bois Diable and K-VIII—and carbon isotope analyses from the first-named site. The combined phytolith and ¹³C isotope analyses evidence the transformation of the landscape from a relatively homogeneous wetland vegetation comprised of a mixture of C4 and C3 plants (the latter including Cyperaceae and other herbaceous monocots such as Marantaceae and Heliconia, Oryzoideae grasses, and other plants typical of frequently flooded areas) to the construction of raised fields that were dominated by C4 plants (maize and other Panicoideae grasses). Our analysis proves the utility of phytoliths for tracing the agricultural history of landscapes, showing that, as in other parts of the Central and South American lowlands, maize (Zea mays) was one important crop cultivated in raised fields. We also estimated the productivity of raised-field agriculture, showing that in combination with other subsistence activities, it certainly had the capacity to sustain sizeable populations.     

Reassessing the northern limit of maize consumption in North America: stable isotope,plant microfossil,and trace element content of carbonized food residue

In combination, the analysis of carbonized food residue for stable C and N isotopes, elemental composition, and plant microfossils (phytoliths and starch granules) offers a powerful tool for understanding patterns of prehistoric maize (Zea mays) consumption in small-scale societies. Using this approach, we conclude that maize was more widely consumed in North America than previously suspected. Between ∼AD 700 and 1600, despite little or no archaeological evidence of gardening, corn was a widespread component of diet on the eastern Canadian prairies. This pattern, furthermore, extended into the adjacent boreal forest at about the same time. However, carbon (δ¹³C) and nitrogen (δ¹⁵N) values on food residue samples vary widely, suggesting significant overall dietary differences from one region to the next. Analysis of a subset of residue samples for elemental composition (using ICP-OES [inductively coupled plasma–optical emission spectrometry]) may help identify broad trends in the provenience of foods consumed at these sites.