Héctor O. Panarello

Hydrogen isotope systematics of hair: archeological and forensic applications

Abstract The hydrogen isotope systematics of hair have been explored and several applications demonstrate the type of information that can be recovered from archeological and forensic hair samples. Experiment with modern hair demonstrate that sources of protein-based hydrogen in keratin are food and water. On the basis of a deuterium-enriched drinking study, it was found that ∼31% of hydrogen in human hair is derived from ingested water. At least 9% of total hydrogen in human hair is isotopically exchangeable with water or water vapor at 25 °C. Nearly complete exchange occurs in a matter of hours. The δD value of body water is approximately 17±10‰ (n=7) more negative than human hair, although there is much scatter in data for modern hair, which is clearly related to variability of the isotopic composition of ingested food and water. Archeological hair samples were analyzed from (i) a 370 year old Incan mummy sacrificed at 5300 m altitude in Argentina (Geoarchaeology 14 (1999) 27) and (ii) from a Woolly Mammoth from Siberia. High spatial resolution data along the length of hair from the mummy indicate seasonal variations in carbon, nitrogen and hydrogen isotope ratios. No hydrogen isotope anomalies are seen in the youngest hair at the base of the scalp, indicating that the individual probably lived at ∼1600 m, and spent less than a week at high altitudes before death. The mammoth also preserves a seasonal signal, suggesting hair growth rates of ∼33 cm/year, faster than human hair, but slower than horse tail hair. The limited isotopic range across seasons for the mammoth is consistent with a north-south migration on the order of 1000 km.

Arsenic and associated trace-elements in groundwater from the Chaco-Pampean plain, Argentina: results from 100 years of research.

The Chaco-Pampean plain, Argentina, is a vast geographical unit (1,000,000 km²) affected by high arsenic (As) concentrations in universal oxidizing groundwater. The socio-economic development of the region is restricted by water availability and its low quality caused by high salinity and hardness. In addition, high As and associated trace-elements (F, U, V, B, Se, Sb, Mo) concentrations of geogenic origin turn waters unsuitable for human consumption. Shallow groundwater with high As and F concentrations (ranges: <10-5300 μg As/L; 51-7,340 μg F/L) exceeding the WHO guideline values (As: 10 μg/L; F: 1,500 μg/L) introduces a potential risk of hydroarsenicism disease in the entire region and fluorosis in some areas. The rural population is affected (2-8 million inhabitants). Calcareous loess-type sediments and/or intercalated volcanic ash layers in pedosedimentary sequences hosting the aquifers are the sources of contaminant trace-elements. Large intra and interbasin variabilities of trace-element concentrations, especially between shallow and deep aquifers have been observed. All areas of the Chaco-Pampean plain were affected in different grades: the Chaco-Salteña plain (in the NNE of the region) and the northern La Pampa plain (in the center-south) have been shown the highest concentrations. The ranges of As and F contents in loess-sediments are 6-25 and 534-3340 mg/kg, respectively in the Salí River basin. Three key processes render high As concentrations in shallow aquifers: i) volcanic glass dissolution and/or hydrolysis and leaching of silicates minerals hosted in loess; ii) desorption processes from the surface of Al-, Fe- and Mn-oxi-hydroxides (coating lithic fragments) at high pH and mobilization as complex oxyanions (As and trace elements)in Na-bicarbonate type groundwaters; and iii) evaporative concentration in areas with semiarid and arid climates. Local factors play also an important role in the control of high As concentrations, highly influenced by lithology-mineralogy, soils-geomorphology, actual climate and paleoclimates, hydraulic parameters, and residence time of groundwaters.

The Inka mummy from Mount Aconcagua: Decoding the geographic origin of the “Messenger to the Deities” by means of stable carbon, nitrogen, and sulfur isotope analysis

Human sacrifices were a ritual practice during the expansion of the Inka Empire. Nevertheless, the homeland of the victims has never been clearly determined. A mummy recently found in a mediterranean environment in the Andes of Argentina provides a unique opportunity to shed some light on the matter. His clothing and funerary trousseau give no evidence regarding his ethnic filiation, geographic origin, nor whether he belonged to the local population or to the Inka elite. Therefore, a decodification of his geographic origin was attempted. This was done through the reconstruction of his palaeodiet: A diet based on continental products would indicate a local origin whereas one including marine food would suggest ties with the Pacific littoral and, indirectly, a foreign origin. Carbon, nitrogen, and sulfur isotope ratios of the mummys bone collagen and hair were compared with values from archaeological populations from littoral and altiplanic environments of South America. The carbon and nitrogen isotopic values of bone collagen were ambiguous tracers, indicating either a continental diet with a high percentage of maize, one including a certain amount of marine products, or a combination of both. The carbon and sulfur isotopic values of hair were conclusive, indicating a clear continental origin of the diet, at least during the period of a year and a half before death.

ANÁLISIS COMPARATIVO DE PALEODIETAS HUMANAS ENTRE LA REGIÓN DEL CANAL BEAGLE Y PENÍNSULA MITRE: PERSPECTIVAS DESDE LOS ISÓTOPOS ESTABLES

Resumen es: En este trabajo aportamos nuevos valores de 13C y 15N medidos sobre restos oseos humanos procedentes del sector meridional de Tierra del Fuego. Estos res...

Radiocarbon age offsets between living organisms from the marine and continental reservoir in coastal localities of Patagonia (Argentina).

The radiocarbon of the local reservoir effect (RE) was observed in many sectors along the Argentinean Patagonia coast. Results show variations in the (super 14) C offsets and differences between marine and continental species growing within the same locality, ranging from about 80-1100 yr BP. It is postulated that such variations are mainly due to local factors, including the coast morphology and the contribution of continental waters. The relevance of these kinds of studies for the interpretation of age in archaeological samples is highlighted in this paper.

Isótopos estables, fauna y tecnología en el estudio de los cazadores-recolectores de la costa norte de Santa Cruz

El objetivo de este trabajo es desarrollar un analisis de isotopos estables del carbono y nitrogeno correspondientes a restos humanos recuperados en la Costa Norte de Santa Cruz (CNSC). Se discuten las pautas generadas a partir de estudios previos del registro arqueologico y etnohistorico para dicho sector en cuanto al uso de recursos marinos por parte de poblaciones cazadoras recolectoras del Holoceno tardio. Estos estudios han propuesto un uso intenso de los recursos marinos en el Holoceno Tardio, lo cual se encuentra respaldado tanto por la distribucion y densidad del registro arqueologico, como por los taxones dominantes de los conjuntos arqueofaunisticos y por el tipo de artefactos vinculados con la explotacion de recursos costeros y marinos. En este trabajo se presentan valores de isotopos estables del carbono y nitrogeno de 10 individuos recuperados en la CNSC con el objetivo de evaluar la importancia relativa de los recursos marinos en paleodietas de poblaciones cazadoras-recolectoras. A partir de esta informacion se registra una amplia variabilidad en las paleodietas con una preponderancia de dietas mixtas, por lo que se propone un uso intensivo pero no exclusivo de los ambitos costeros, combinado con la ingesta de recursos terrestres. Esta interpretacion contrasta con el registro arqueofaunistico de la CNSC que esta dominado por recursos marinos. Se plantea una complementacion de ambientes litorales con movimientos hacia sectores interiores proximos, donde se explotarian recursos terrestres. Asimismo, la evidencia isotopica senala que el uso de los recursos marinos en este sector no fue mas intensivo que el registrado en otros sectores costeros de Patagonia continental.

Stable carbon isotope measurements on hair from wild animals from altiplanic environments of Jujuy, Argentina

The use of stable carbon isotopes as dietary tracers is an application that is widening its scope within the fields of ecology and paleoecology. Although hair is potentially one of the most favorable animal tissues for isotopic measurement for dietary studies, this tissue is rarely included in research works. This may be due to the fact that many aspects related to hair tissue are not fully understood, especially in the case of wild animals whose diets consist of plants with contrasting 13 C/ 12 C ratios, their abundance depending on seasonality. The present isotopic study of hair from animals inhabiting the Andes in northwestern Argentina, at heights ranging from 3500 to about 5000 m above sea level (asl) shows that 1) δ 13 C values measured on hair from herbivores with a mixed and isotopically contrasting diet, and from their carnivorous predators, differ in their respective trophic levels, 2) in primary consumers, different types of hair from the same individual have different δ 13 C values, whereas hair values are homogeneous in carnivores, and 3) some types of hair from rodents, such as whiskers, show δ 13 C values similar to those of less metabolically active tissues such as bone collagen.

ISÓTOPOS ESTABLES DEL CARBONO EN PATAGONIA MERIDIONAL: DATOS DE LA CUENCA DEL LAGO SALITROSO (PROVINCIA DE SANTA CRUZ, REPÚBLICA ARGENTINA)

This work presents and discusses the carbon isotope data obtained from the analysis of human bone remains from 25 individuals of the locale of Sierra Colorada (Salitroso lake basin), 19 of which have been dated directly by

Isotopic evidence of weaning in hunter-gatherers from the late holocene in Lake Salitroso, Patagonia, Argentina

OBJECTIVESnThe timing and duration of breastfeeding and weaning in past hunter-gatherer populations are discussed based on the results of stable carbon and nitrogen isotope analyses undertaken on a Late Holocene skeletal sample from Lake Salitroso in the Patagonian steppe (Argentina). Research in Lake Salitroso is part of a regional project that studies the relationship between hunter-gatherer societies, their organizational systems and the environmental changes during the last 3,000 years in Patagonia.nnnMETHODSnThe sample included 52 individuals: 33 subadults and 19 adults of both sexes. They were recovered from 24 burial stone structures, locally called chenques, with dates ranging from ca. 800 BP to 350 BP. Ribs were selected for collagen extraction and measurement of (13) C/(12) C and (15) N/(14) N ratios.nnnRESULTSnA δ(13) C mean value of -18.7‰u2009±u20090.5‰ was obtained, with a range between -19.8‰ and -17.1‰ whereas δ(15) N recorded a mean of 11.9‰u2009±u20091.1‰ with a range between 10.1‰ and 14.8‰. δ(15) N data showed an age-related pattern with particularly marked difference between values for subadults under the age of 4 and older individuals. As opposed to δ(15) N, δ(13) C showed little variation with age.nnnCONCLUSIONSnAn early incorporation of supplementary solid food between 0.75 and 2 years of age and a late cessation of breastfeeding at about 5-6 years of age were inferred. This suggests that among this Patagonian hunter-gatherer population weaning was a gradual and lengthy process. These results are consistent with the patterns observed in cross-cultural studies and archaeological samples of hunter-gatherer groups.

Chemostratigraphy of the Pliensbachian, Puesto Araya Formation (Neuquén Basin, Argentina)

In a preliminary attempt to establish an isotope stratigraphy, strontium, carbon and oxygen isotope ratios were determined from marine biogenic carbonates of Pliensbachian age, in the context of scheme of local ammonite Zones correlatable to the European Standard Zonation. Two sections, rio Atuel and arroyo Serrucho, of the mainly siliciclastic Puesto Araya Formation, Neuquen Basin, south-western Mendoza, Argentina, were studied. Specimens of the bivalve genera Weyla Bhom and Gryphaea Lamarck were selected for the isotopic determinations because of their low-Mg calcite original mineralogy and widespread presence. Scanning electron microscopy, X-ray diffraction and X-ray fluorescence spectrometry techniques were used to control the good degree of preservation of most of the biogenic material, as evidenced by pristine fabrics, 100% calcite composition and Sr, Mn and Fe concentrations. Although strontium isotope ratios are slightly scattered, it is possible to compare them with those of the Early Jurassic seawater reference curve. Carbon isotope signals show two relative maxima, correlatable with those recorded for the upper part of the Ibex Zone and the middle part of the Margaritatus Zone in various European sections, indicating the possible global significance of these events. d18O values were found to be unreliable for isotope stratigraphy, as they are largely depleted in comparison to those of coeval unaltered marine carbonates.