Substantial progress in the application of multiple isotope analyses has greatly improved the ability to identify nonlocal individuals amongst archaeological populations over the past decades. More recently the development of large scale models of spatial isotopic variation (isoscapes) has contributed to improved geographic assignments of human and animal origins. Persistent challenges remain, however, in the accurate identification of individual geographic origins from skeletal isotope data in studies of human (and animal) migration and provenance. In an attempt to develop and test more standardized and quantitative approaches to geographic assignment of individual origins using isotopic data two methods, combining 87Sr/86Sr and δ18O isoscapes, are examined for the Circum-Caribbean region: 1) an Interval approach using a defined range of fixed isotopic variation per location; and 2) a Likelihood assignment approach using univariate and bivariate probability density functions. These two methods are tested with enamel isotope data from a modern sample of known origin from Caracas, Venezuela and further explored with two archaeological samples of unknown origin recovered from Cuba and Trinidad. The results emphasize both the potential and limitation of the different approaches. Validation tests on the known origin sample exclude most areas of the Circum-Caribbean region and correctly highlight Caracas as a possible place of origin with both approaches. The positive validation results clearly demonstrate the overall efficacy of a dual-isotope approach to geoprovenance. The accuracy and precision of geographic assignments may be further improved by better understanding of the relationships between environmental and biological isotope variation; continued development and refinement of relevant isoscapes; and the eventual incorporation of a broader array of isotope proxy data.

Abstract

Abstract:The archaeology of Amerindian settlements in the Caribbean has mostly been identified through scatters of artefacts; predominantly conglomerations of shells, ceramics and lithics. While archaeological material may not always be visible on the surface, particular settlement patterns may be identifiable by a topography created through cultural action: earthen mounds interchanging with mostly circular flattened areas. In northern Hispaniola, recent foot surveys have identified more than 200 pre-colonial sites of which several have been mapped in high resolution. In addition, three settlements with topographical characteristics have been extensively excavated, confirming that the mounds and flattened areas may have had a cultural connotation in this region. Without the availability of high resolution LiDAR (Light Detection and Ranging) data, a photogrammetric approach using UAS (unmanned aircraft system, commonly known as drones) can fill the knowledge gap on a local scale, providing fast and reliable data collection and precise results. After photogrammetric processing, digital clearance of vegetation, and extraction of the georeferenced DEM (digital elevation model) and orthophoto, filters and enhancements provide an opportunity to visualize the results in GIS. The outcome provides an overview of site size, and distribution of mounds and flattened areas. Measurement of the topographic changes in a variety of past settlements defines likely zones of habitat, and provides clues on the actual dimensions and density of living space. Understanding the relation of the mounds and adjacent flat areas within their environment allows a discussion on how, and for what purpose, the settlement was founded at a particular location, and provides clues about its spatial organization.

Archeological excavations of Amerindian sites on Dos Mosquises Island, Los Roques Archipelago, Venezuela, uncovered a wide range of evidence reflecting seasonal exploitation of local resources and multiple ritual depositions of large quantities of ceramic figurines, lithics, and faunal remains. Zooarchaeological analysis revealed the presence of modified and unmodified bones and teeth from numerous imported mammal species. Local geographic and environmental conditions preclude permanent establishment of terrestrial mammal populations and as such, there are no native mammalian taxa on the island itself or the surrounding oceanic archipelago. The presence of these faunal remains on Dos Mosquises can be attributed to the intentional movement of animal resources from the mainland to Los Roques by indigenous groups in the Late Ceramic Age (~AD 1200-1500). Despite attributions to a mainland source region, little else is known about the origins of these unique specimens. Here, we apply strontium (87 Sr/ 86 Sr), oxygen (δ 18 O), and carbon (δ 13 C) isotope analyses of tooth enamel from various archeologically recovered taxa including deer, peccary, tapir, ocelot, margay, opossum, fox, and weasel to investigate their geographic origins via comparisons with macro-regional models of precipitation δ 18 O and bioavailable 87 Sr/ 86 Sr. The 87 Sr/ 86 Sr results are highly variable both for the overall assemblage and between specimens within the same taxa, indicating origins from different geochemical environments of mainland South America. The combined archeological and isotopic evidence are consistent with origins within the late pre-colonial Valencioid Sphere of Interaction which encompassed the Lake Valencia Basin, surrounding regions, and several offshore island groups including Los Roques archipelago.