Keeping Track: Ceremonial Racetracks, Integration, and Change in Central Arizona

Beginning in 2006 and as part of Arizona State University’s Legacies on the Landscape Project (Spielmann et al. 2005), I undertook preliminary research regarding a small corpus of long, linear clearings in the Perry Mesa region of Central Arizona. Coined “racetracks”, these had been recorded at the eight largest pueblos on Perry Mesa and neighboring Black Mesa. They had been noted by past archaeologists (e.g., Ahlstrom and Roberts 1995:37; Ahlstrom et al. 1992; North 2002; Wilcox et al. 2001; Wood 1985), sometimes mapped, and routinely speculated upon, but never subjected to systematic study. Efforts since have resulted in the identification of additional features (Figure 1), the collection of data on many of them, and perhaps some insight into their function within the social landscape of the prehispanic Southwest (Russell 2007, 2008, 2010; Russell and Freeman 2010a, 2010b; Russell et al. 2008, 2011).In the summer of 2009, I investigated deep soil properties and mineral-derived nutrients on fields near Pueblo La Plata, one of the largest pueblos on Perry Mesa. To examine the effects of rock alignments and agricultural harvest independent of one another, I sampled soils from replicated plots behind alignments paired with nearby plots that are not bordered by an alignment in both areas of high and low prehistoric agricultural intensity. I investigated soil provena nce and the influence of deposition on mineral-derived nutrients through analysis of the chemical composition of the soil, bedrock and dust. Agricultural rock alignments were significantly associated with differences in soil texture, but neither rock alignments nor agricultural history were associated with significant differences in mineral-derived nutrients. Instead, eolian deposition may explain why nutrient pools are similar across agricultural history and rock alignment presence. Eolian deposition homogenized the surface soil, reducing the spatial heterogeneity of soils. Dust is important both as a parent material to the soils on Perry Mesa, and also a source of mineral-derived nutrients. This investigation suggests that prehistoric agriculture on Perry Mesa was not likely limited by long term soil fertility, but instead could have been sustained by eolian inputs.