Investigating regional mobility in the southern hinterland of the Wari empire: Biogeochemistry at the site of Beringa, Peru

Abstract

Empires have transformed political, social, and environmental landscapes in the past and present. Although much research on archaeological empires focuses on large-scale imperial processes, we use biogeochemistry and bioarchaeology to investigate how imperialism may have reshaped regional political organization and regional migration patterns in the Wari Empire of the Andean Middle Horizon (ca. AD 600-1000). Radiogenic strontium isotope analysis of human remains from the site of Beringa in the Majes Valley of southern Peru identified the geographic origins of individuals impacted by the Wari Empire. At Beringa, the combined archaeological human enamel and bone values range from (87)Sr/(86)Sr = 0.70802 - 0.70960, with a mean (87)Sr/(86)Sr = 0.70842 ± 0.00027 (1σ, n = 52). These data are consistent with radiogenic strontium isotope data from the local fauna in the Majes Valley and imply that most individuals were local inhabitants, rather than migrants from the Wari heartland or some other locale. There were two outliers at Beringa, and these "non-local" individuals may have derived from other parts of the South Central Andes. This is consistent with our understanding of expansive trade networks and population movement in the Andean Middle Horizon, likely influenced by the policies of the Wari Empire. Although not a Wari colony, the incorporation of small sites like Beringa into the vast social and political networks of the Middle Horizon resulted in small numbers of migrants at Beringa.

Patterns of camelid management in Wari Empire reconstructed using multiple stable isotope analysis: evidence from Castillo de Huarmey, northern coast of Peru

“…Older sedimentary and Precambrian metamorphic rocks (lead isotope Province III) outcrop to the east of the Mesozoic sediments and are expected to show the highest Sr and the most variable Pb isotope ratios in the region. Recent work confirms this general pattern for Sr as the coastal Andean valleys show lower Sr isotope ratios, although alluvial soils accumulated along riverbanks could incorporate Sr from the adjacent highlands (Knudson and Tung 2011;Knudson et al 2014). …”

Identifying locals, migrants, and captives in the Wari Heartland: A bioarchaeological and biogeochemical study of human remains from Conchopata, Peru

“…Additionally, given the unique context of the trophy heads, which can reveal insights into how militaristic and ritual activities were integrated into Wari society, we also examine new radiogenic strontium isotope ratios from a larger sample of Wari trophy heads to further clarify the frequency of this practice and to suggest possible geographical origins of some of those trophy head victims (and exclude other regions as possible sources of captives). This latter aspect of the study has been made possible by the expanding database on radiogenic strontium isotope ratios in the Andes (Andrushko et al, 2009(Andrushko et al, , 2011Bethard et al, 2008;Conlee et al, 2009;Knudson et al, 2004Knudson et al, , 2005Knudson and Price, 2007;Knudson and Torres-Rouff, 2009;Knudson, 2011;Knudson and Tung, 2011;Slovak et al, 2009;Torres-Rouff and Knudson, 2007;Turner et al, 2009).…”

“…For example, much work has focused on identifying the bioavailable radiogenic strontium isotope ratio for communities within the Tiwanaku polity (Knudson and Price, 2007;Knudson and Blom, 2009), which was contemporaneous with the Wari Empire, but located in the south central Andes. More recently, scholars have focused on other Middle Horizon populations on the coast near Lima (Slovak et al, 2009), in the Majes Valley of southern Peru (Knudson and Tung, 2011), and in Cusco (Andrushko et al, 2009), as well as both earlier and later polities like the Nasca of the Early Intermediate Period (AD 1-600) Conlee et al, 2009), the Chiribaya of the Late Intermediate Period (AD 1000-1400) (Knudson and Buikstra, 2007;Knudson and Price, 2007), and the Inka Empire of the Late Horizon (AD 1400-1532) (Andrushko et al, 2008;Turner et al, 2009).…”

Human Response to Climate Change during the Umm an‐Nar/Wadi Suq Transition in the United Arab Emirates

“…Under vacuum, samples were acidified with 100% ortho-phosphoric acid, cryogenically purified and normalised using (Pollard et al, 2011;Chenery et al, 2012). Correspondingly, until larger δ 18 O c(VPDB) datasets are available to more accurately generate local oxygen isotope baselines in the region, it is more appropriate to interpret locality using δ 18 O c(VPDB) ratios from human archaeological enamel produced in this study (see Knudson & Tung (2011) for a similar discussion of defining local strontium ranges using human values). Finally, because of small and variable sample sizes as well as non-normal data distributions, non-parametric Mann-Whitney U statistical analyses were performed using SAS 9.3.…”