Development and evaluation of geochemical methods for the sourcing of archaeological maize

Abstract

Strontium (Sr)-isotope values on bone from deer mice pairs from 12 field sites in the Chaco Canyon area, New Mexico, were compared with isotope values of synthetic soil waters from the same fields. The data indicate that mice obtain Sr from near-surface sources and that soil samples collected at depths ranging from 25 to 95 cm contain Sr that is more accessible to the deep roots of maize; thus, synthetic soil solutions provide better data for the sourcing of archaeological maize. However, the Sr-isotope composition of mice may be more valuable in sourcing archaeological remains of animals such as rabbit, turkey, and deer.In a separate study, five Native American maize (Zea mays L. ssp. mays) accessions grown out at New Mexico State University Agricultural Science Center, Farmington, New Mexico were used to determine if soil-water metal pairs partition systematically into cobs and kernels. The sampled maize included landraces from three Native American groups (Acoma, Hopi, Zuni) that still occupy the Four Corners area. Two cobs each were picked from 10 plants of each landrace. Partitioning of the Ba/Mn, Ba/Sr, Ca/Sr, and K/Rb metal pairs from the soil water to the cob appears to behave in a systematic fashion. In addition, 51 rare earth element (REE) pairs also appear to systematically partition from the soil water into cobs; however, the ratios of the REE dissolved in the soil waters are relatively invariant; therefore, the distribution coefficients that describe the partitioning of REE from the soil water to the cob may not apply to archeological cobs grown under chemically heterogeneous conditions. Partitioning of Ba/Rb, Ba/Sr, Mg/P, and Mn/P metal pairs from the soil water to kernels also behaves in a systematic fashion. Given that modern Native American landraces were grown under optimal environmental conditions that may not have been duplicated by prehistoric Native Americans, the distribution coefficients obtained in this study should be used with caution.

Passports from the past: Investigating human dispersals using strontium isotope analysis of tooth enamel

“…Co-incidentally, this is also a value that would indicate food sourced on marine carbonates such as chalks and limestone , Montgomery et al 2007a). If such a value were obtained from the inhabitants of Skye, it could be attributed to the Durness limestone valley to the south of the Cuillins which is sheltered and fertile Transported atmospheric dust and aerosols may be a major consideration when working in arid or continental regions (Andersson et al 1990, Benson et al 2008, Negrel and Roy 1998, but is less of a problem in temperate, maritime islands such as the British Isles where rainfall is the major source of atmospheric deposition. The Isle of Skye, like much of the western Atlantic seaboard of Britain, has high rainfall throughout the year and increasing rainfall has been shown to gradually shift the ratios of strontium available to plants away from the rock toward that of rainwater ( Figure 6) (Capo et al 1998, Raiber et al 2009), which in coastal regions is close to seawater, i.e.…”

Possible sources of archaeological maize found in Chaco Canyon and Aztec Ruin, New Mexico

“…This paper represents the fourth in a series of studies (Benson et al, 2003(Benson et al, , 2006(Benson et al, , 2008 that seek to determine the source(s) of archaeological corn cobs (hereafter referred to as cobs) found in Chaco Canyon. In the first study, Benson et al (2003) Ruin (two sites) and Aztec Ruin (three soil sites) (both located in the Totah region), and Chaco Canyon itself (10 soil sites).…”

“…In the third study, Benson et al (2008) sought to refine tracemetal distribution coefficients that describe the systematic partitioning of some metal pairs from soil-water into a cob. According to these authors ''The use of the distribution coefficient accounts for Table 2.…”

“…In order to refine the results of earlier studies, Benson et al (2008) selected two cobs from each of 10 plants from each of five Native American landraces grown out at New Mexico State University's Agricultural Science Center, Farmington, New Mexico (Adams et al, 2006). Soils were obtained from both sides of the corn row at the base of each stalk at depths centered on 35 and 70 cm.…”

“…Soils were obtained from both sides of the corn row at the base of each stalk at depths centered on 35 and 70 cm. After a series of pretreatments (see methods section in Benson et al, 2008), multitrace-metal determinations were performed on the cobs and the synthetic soil-waters, using inductively coupled plasma-massspectrometry (ICP-MS) and ICP emission spectrometry (ICP-AES). Using all paired combinations of the 51 measured trace-metals, it was determined that four metal pairs (Ba/Sr, Ba/Mn, Ca/Sr, and K/Rb) exhibited systematic distribution coefficients (standard deviation of a metal pair K D for a particular landrace was 33% of its mean value) between soil-waters and all cob types.…”