Mark R. Schurr

Using stable nitrogen-isotopes to study weaning behavior in past populations

Abstract Several different methods have been used to explore weaning behavior in past populations, including demographic profiles, non‐specific osteological indicators of stress, and bone chemistry studies. Stable nitrogen‐isotope ratios of prehistoric bone proteins provide an especially useful method for reconstructing the weaning patterns of archaeological populations. A demographic measure of fertility (the D30+/D5+ ratio) is compared with age‐related changes in stable nitrogen‐isotope ratios for human burials from one historic cemetery and two prehistoric ones. The stable nitrogen‐isotope ratios show that each population had a characteristic and distinctive combination of weaning time and rate, and that neither the timing nor tempo of weaning was clearly correlated with the demographic measure of fertility. These results demonstrate the feasibility of using stable nitrogen‐isotope ratios to compare weaning patterns and fertility in past populations. This example also shows that the relationship betwee...

Isotopic and Mortuary Variability in a Middle Mississippian Population

Stable-isotopic studies of prehistoric diet have usually confined discussions of isotopic variability within populations to sex-related differences in diet and have rarely considered other social or cultural sources of dietary variation. Extant data from eastern North America suggest that isotopic variation (and hence dietary variation) may have been greatest within the relatively complex Middle Mississippian societies of the late prehistoric period. Correlations between isotopic variability and mortuary variability (an indication of social position) were identified in a sample of burials from the Angel site, a Middle Mississippian (A.D. 1200-1450) civic-ceremonial center in southwestern Indiana. These correlations demonstrate how contextually informed isotopic studies can be used to examine the relations between social position and diet. This approach may be especially useful for studies of social interactions between different populations.

Fluoride dating of faunal materials by ion-selective electrode: High resolution relative dating at an early agricultural period site in the Tucson Basin

When the fluoride content of bone is measured with an ion-selective electrode, and when the technique is correctly applied, fluoride dating is a very economical method for developing fine-scale relative chronologies. It has been successfully used to develop relative chronologies for prehistoric human burials and fossilized bones throughout the world, but its much greater potential for the dating of unfossilized faunal materials has been neglected. The fluoride contents of 889 lagomorph and 16 artiodactyl bones from 183 contexts at Los Pozos, an Early Agricultural period site in Arizona, illustrate how fluoride measurements can be used to date features. Fluoride dating offers a temporal resolution capable of distinguishing between features separated by as little as 20 to 40 years.

Intergroup variation in stable isotope ratios reflects anthropogenic impact on the Barbary macaques (Macaca sylvanus) of Gibraltar

Interactions with humans impact many aspects of behavior and ecology in nonhuman primates. Because of the complexities of the human–nonhuman primate interface, methods are needed to quantify the effects of anthropogenic interactions, including their intensity and differential impacts between nonhuman primate groups. Stable isotopes can be used to quickly and economically assess intergroup dietary variation, and provide a framework for the development of specific hypotheses about anthropogenic impact. This study uses stable carbon and nitrogen isotope analysis to examine intraspecific variation in diet between five groups of Barbary macaques, Macaca sylvanus, in the Upper Rock Nature Reserve, Gibraltar. Analysis of hair from 135 macaques showed significant differences in δ13C and δ15N values between a group with minimal tourist contact and groups that were main tourist attractions. Because we observed no overt physiological or substantial behavioral differences between the groups, feeding ecology is the most likely cause of any differences in stable isotope ratios. Haphazard provisioning by tourists and Gibraltarians is a likely source of dietary variation between groups. Stable isotope analysis and observational data facilitate a deeper understanding of the feeding ecology of the Barbary macaques relevant to the role of an anthropogenic ecology for the species.

Fluoride dating of prehistoric bones by ion selective electrode

Abstract The fluoride contents of prehistoric bones can be used to determine the relative ages of the specimens with ease when fluoride content is measured using an ion selective electrode. Measurements of fluoride contents of ribs from prehistoric burials from the Angel Site, a large prehistoric village and ceremonial center in southwestern Indiana, demonstrate that fluoride dating can be used to determine the occupational chronology of a prehistoric site where other methods of dating are inapplicable.

5 – THERMALLY INDUCED CHANGES IN THE STABLE CARBON AND NITROGEN ISOTOPE RATIOS OF CHARRED BONES

Publisher Summary Cremations, whether accidental or deliberate, are difficult to work with because they are usually fragmentary. However, cremation is rarely complete, and cremated burials often provide bone fragments suitable for many types of osteological investigations. Morphological analyses of cremated bones can provide information about sex, age, health, and cause of death. It is often assumed that cremation produces highly oxidized bone fragments that are little more than inorganic ash, but this is not the case for most prehistoric cremations. Bone fragments often display a gradient of thermal alteration, ranging from calcined through blackened to apparently unaltered, sometimes even on the same bone. Burned bones can also be subjected to chemical studies, although these are rarely done. Many cremations produce bones that still contain organic matter in the form of thermally altered organics or reduced carbon. This is especially true for prehistoric cremations, where the large amount of fuel necessary for a total cremation may not have been readily available to nonindustrial societies. In many cases, charred bones from archaeological contexts can be expected to contain more organic carbon than uncharred bones from the same context, because reduced carbon in charred bone is more resistant to diagenetic change than uncharred collagen and other organic fractions of bone. Cremated burials would provide an abundant and promising source of paleodietary data through isotope studies if correct techniques were available.

The Thermal History of Maize Kernels Determined By Electron Spin Resonance

Electron spin resonance (ESR) can be used to determine the thermal history of charred organic material. Maize seeds were heated under controlled conditions in order to produce calibration curves relating g-values (the rate of electron splitting) and spin intensities (the number of spin centres) to heating temperatures, times and conditions. These experiments reproduced results that had been previously obtained by other laboratories, with some minor exceptions. The calibration curves were then used to reconstruct the thermal histories of charred maize kernels from several prehistoric sites in eastern North America. At these sites, the differing thermal histories of maize kernels are correlated with depositional contexts.

A Test for Maize Consumption by Fauna in Late Prehistoric Eastern North America

It has been suggested that some animals eaten by late prehistoric populations of eastern North America were pest species that consumed maize. This could lead to over-estimates of amounts of maize that were directly consumed in prehistoric human diets. Stable carbon- and nitrogen-isotope ratios of collagen from white-tailed deer and raccoon bones from the Late Archaic Indian Knoll and Middle Mississippian Angel sites are compared. The stable isotope ratios are used to determine the amount of maize, if any, in Middle Mississippian faunal diets. We find no evidence that deer or raccoon at the Angel site consumed maize.

Using the concept of the learning curve to increase the productivity of geophysical surveys

Geophysical techniques offer many advantages and should be part of the common practice of field archaeology. However, geophysical instruments are useful only when they are operated correctly and efficiently. New or potential users want to obtain effective results as rapidly as possible and experienced users are constantly seeking to improve the results of geophysical surveys. The concept of the learning curve can be used to develop techniques and approaches that increase both the effectiveness of geophysical surveys in archaeology and the speed with which geophysical techniques are learned and applied.

ARCHAEOLOGICAL INDICES OF RESISTANCE: DIVERSITY IN THE REMOVAL PERIOD POTAWATOMI OF THE WESTERN GREAT LAKES

Dichotomies or bipolar scales usually provide the conceptual framework for discussions of historic period Native American cultural change in the western Great Lakes. Archaeological and historical studies of Removal period (A.D. 1795-1840) Potawatomi of northern Indiana and southern Michigan provide challenges to common dichotomous frameworks used to define identity, political affiliation, geographic location, or other attributes of individual Potawatomi. Examples of these classifications include dichotomies such as Catholic vs. Non-Catholic, assimilationist vs. traditionalist, or accommodationist vs. non-accommodationist (among others). Case studies of four Potawatomi, two of whom successfully resisted removal (Pokagon and Benack) and two who did not (Menominee and Ashkum), illustrate the need for multiple lines of evidence that facilitate comparisons between diverse communities living in a rapidly changing world. Relations with the colonizer were the most significant element related to successful resistance. Site location provides a visible signal of these wider social ties extending beyond the local community.