Origin of deep saline groundwaters in the Vienne granitic rocks (France): constraints inferred from boron and strontium isotopes

As part of a preliminary geological characterization programme to assess the feasibility of an underground laboratory in granitic rock, a series of 17 deep boreholes (maximum depth, 900 m) was drilled by ANDRA in the Vienne district, France. A salinity gradient was demonstrated in the granitic waters with concentrations varying from approximately 1 g L^?1 at 150 m depth at the top of the basement (beneath the sedimentary cover) to 10 g L^?1 in the deeper part (from 400 to 600 m depth). Sr and B isotope ratios were measured in order to better understand the origin of the salinity and to evaluate the degree of water–rock interaction in the system. The results obtained were compared to those of mineral spring waters emerging from the granitic basement in the Massif Central. Evidence in support of a significant marine contribution include: (i) the Cl–Br investigations agree with a marine origin for the saline groundwaters without evolution from seawater; (ii) the ⁸⁷Sr/⁸⁶Sr ratio of the Vienne deep groundwaters (0.7078–0.7084) is in agreement with a palaeo‐seawater isotopic signature; (iii) measured δ¹¹B values for the deepest brine samples are enriched in ¹¹B (up to 36.1‰) relative to the granitic springs. The combined use of δ¹¹B, Cl, B, Br, Sr contents and ⁸⁷Sr/⁸⁶Sr ratios makes it possible to define and quantify a mixing model between marine and crustal end‐members in order to explain the origin of the deep saline groundwaters in the Vienne granitic rocks.     

Provisioning Inka feasts at Tiwanaku, Bolivia: the geographic origins of camelids in the Pumapunku complex

While political integration can be achieved by many means, here we focus on the use of feasting and statecraft in the Inka Empire of the Andean Late Horizon (c. AD 1400-1532) in South America. In order to examine Inka political integration of the Lake Titicaca Basin of Bolivia, we examine paleomobility and paleodiet through radiogenic strontium and stable oxygen and carbon isotope data in archaeological camelid remains from the site of Tiwanaku. Mean radiogenic strontium isotope values from all archaeological camelid enamel and bone samples is ⁸⁷Sr/⁸⁶Sr = 0.70998 ± 0.00179 (1σ, n = 48), mean stable oxygen isotope values from a sub-set of archaeological camelid enamel and bone samples is δ¹⁸O_{carbonate (VPDB)} = −10.0‰ ± 2.6‰ (1σ, n = 18) and mean stable carbon isotope values from a sub-set of archaeological camelid enamel and bone samples is δ¹³C_{carbonate (VPDB)} = −9.0‰ ± 1.7‰ (1σ, n = 18). While many camelids consumed in these feasting events were likely local to the Lake Titicaca Basin, others came from a variety of different geologic zones, elucidating our understanding of Inka statecraft and the role of feasting in political integration in empires in the past.     

Reconstructing Neolithic groups in Sarawak,Malaysia through lead and strontium isotope analysis

Heavy stable isotope analysis of mid-late Holocene Neolithic burials from Sarawak (Malaysia) identifies groups not apparent in mortuary treatment or inferred subsistence. Isotope ratios of strontium (⁸⁷Sr/⁸⁶Sr) and lead (²⁰⁸Pb/²⁰⁴Pb, ²⁰⁷Pb/²⁰⁴Pb, ²⁰⁶Pb/²⁰⁴Pb) from adult tooth enamel show distinct groups at Niah Cave's West Mouth organized by dietary catchment. Two roughly contemporary sites, Gua Sireh and Lobang Angin, are included to assess regional heterogeneity in northern Borneo. Heavy stable isotope ratios for humans differ from sampled modern plants and archaeological fauna from West Mouth, and suggest a non-local origin for some of the West Mouth human remains. Distinct heavy isotope ratios characterize all three sites and show regional differentiation broadly consistent with geological expectations. Results supplement paleodiet and morphological analyses and have implications for clarifying Niah Cave mortuary use during the mid-late Holocene. Further and more precise geographic placement will follow through additional landscape sampling for strontium and lead isotope values.     

Precipitation of fracture fillings and cements in the Buntsandstein (NW Germany)

The relationship between fracturing and fracture filling in opening‐mode fractures in the Triassic Buntsandstein in the Lower Saxony Basin (LSB; NW Germany) has been studied by an integration of petrographic and structural analysis of core samples, strontium isotope analysis and microthermometry on fluid inclusions. This revealed the relationship between the timing of the fracturing and the precipitation of different mineral phases in the fractures by constraining the precipitation conditions and considering the possible fluid transport mechanisms. The core was studied from four different boreholes, located in different structural settings across the LSB. In the core samples from the four boreholes, fractures filled with calcite, quartz and anhydrite were found, in addition to pore‐filling calcite cementation. In boreholes 2 and 3, calcite‐filled fractures have a fibrous microstructure whereas in borehole 1, fractures are filled with elongate‐blocky calcite crystals. Anhydrite‐filled fractures have, in all samples, a blocky to elongate‐blocky microstructure. Fractures that are filled with quartz are observed in borehole 2 only where the quartz crystals are ‘stretched’ with an elongated habit. Fluid inclusion microthermometry of fracturing‐filling quartz crystals showed that quartz precipitation took place at temperatures of at least 140°C, from a fluid with NaCl–CaCl₂–H₂O composition. Melting phases are meta‐stable and suggest growth from high salinity formation water. Strontium isotopes, measured in leached host rock, indicate that, in boreholes 2 and 3, the fluid which precipitated the calcite cements and calcite‐filled fractures is most likely locally derived whereas in borehole 1, the ⁸⁷Sr/⁸⁶Sr ratios from the pore‐filling cements and in the elongate‐blocky calcite‐filled fracture can only be explained by mixing with externally derived fluids. The elongate‐blocky anhydrite‐filled fractures, present in boreholes 1, 3 and 4, precipitated from a mixture of locally derived pore fluids and a significant quantity of fluid with a lower, less radiogenic, ⁸⁷Sr/⁸⁶Sr ratio. Taking into account the structural evolution of the basin and accompanying salt tectonics, it is likely that the underlying Zechstein is a source for the less radiogenic fluids. Based on the samples in the LSB, it is probable that fibrous fracture fillings in sedimentary rocks most likely developed from locally derived pore fluids whereas elongate‐blocky fracture fillings with smooth walls developed from externally derived pore fluids.     

Strontium isotopic characterization of the Palmottu hydrosystem (Finland): water–rock interaction and geochemistry of groundwaters

The Palmottu hydrosystem is located in a granitic host rock in southern Finland. Along well‐defined pathways in the fractured crystalline rock, strontium isotopes are used to trace the degree of water–rock interaction (WRI) and mixing processes in groundwaters. The ⁸⁷Sr/⁸⁶Sr ratios range between 0.716910 and 0.735606 in the surface waters and between 0.719991 and 0.750787 in the groundwaters, but are between 0.720 and 0.735 in most of the samples. Moreover, the results show a lack of correlation between the water chemistries determining the classification into different water‐types (Na–Cl, Na–SO₄, etc.) and the results of the strontium (Sr) contents and Sr isotopic ratios. From a WRI standpoint, this implies that the Sr behaviour is independent of the water chemistry; the occurrence of large ⁸⁷Sr/⁸⁶Sr variations is site specific and mainly dependent on the lithology. A model to determine the ⁸⁷Sr/⁸⁶Sr ratio of water after interaction with granite was developed. This model is based on the assumption that Sr was derived from three minerals: plagioclase, K‐feldspar and biotite. The results of the calculation indicate that around half of the water analysed within the Palmottu hydrosystem can be explained by the weathering of the granites. However, clearly lower ⁸⁷Sr/⁸⁶Sr are observed in waters when compared to the calculated ⁸⁷Sr/⁸⁶Sr and other sources of Sr, with low ⁸⁷Sr/⁸⁶Sr, rather than the calculated granite–water interaction, which may be suspected. When comparing the ⁸⁷Sr/⁸⁶Sr and ion ratios (Ca/Na, Mg/Na, Sr/Na, Cl/Na), the scattering of the data can be explained by the presence of four end‐members: a brine component (low ⁸⁷Sr/⁸⁶Sr and Ca/Na ratios…), a deep granitic component (high ⁸⁷Sr/⁸⁶Sr ratios and low Ca/Na ratios…), a subsurface component (intermediate ⁸⁷Sr/⁸⁶Sr ratios associated with high Ca/Na ratios…) and a surface end‐member:snow and river drainage (low ⁸⁷Sr/⁸⁶Sr and low Ca/Na ratios…). These extreme end‐members define a series of WRI‐mixing line within a rather complex hydrosystem.     

Origin of palaeo‐waters in the Ordovician carbonates in Tahe oilfield,Tarim Basin: constraints from fluid inclusions and Sr,C and O isotopes

Petrographic features, isotopes, and trace elements were determined, and fluid inclusions were analyzed on fracture‐filling, karst‐filling and interparticle calcite cement from the Ordovician carbonates in Tahe oilfield, Tarim basin, NW China. The aim was to assess the origin and evolution of palaeo‐waters in the carbonates. The initial water was seawater diluted by meteoric water, as indicated by bright cathodoluminescence (CL) in low‐temperature calcite. The palaeoseawater was further buried to temperatures from 57 to 110°C, nonluminescent calcite precipitated during the Silurian to middle Devonian. Infiltration of meteoric water of late Devonian age into the carbonate rocks was recorded in the first generation of fracture‐ and karst‐filling dull red CL calcite with temperatures from <50°C to 83°C, low salinities (<9.0 wt%), high Mn contents and high ⁸⁶Sr/⁸⁷Sr ratios from 0.7090 to 0.7099. During the early Permian, ⁸⁷Sr‐rich hydrothermal water may have entered the carbonate rocks, from which precipitated a second generation of fracture‐filling and interparticle calcite and barite cements with salinities greater than 22.4 wt%, and temperatures from 120°C to 180°C. The hydrothermal water may have collected isotopically light CO₂ (possibly of TSR‐origin) during upward migration, resulting in hydrothermal calcite and the present‐day oilfield water having δ¹³C values from ?4.3 to ?13.8‰ and showing negative relationships of ⁸⁷Sr/⁸⁶Sr ratios to δ¹³C and δ¹⁸O values. However, higher temperatures (up to 187°C) and much lower salinities (down to 0.5 wt%) measured from some karst‐filling, giant, nonluminescent calcite crystals may suggest that hydrothermal water was deeply recycled, reduced (Fe‐bearing) meteoric water heated in deeper strata, or water generated from TSR during hydrothermal water activity. Mixing of hydrothermal and local basinal water (or diagenetically altered connate water) with meteoric waters of late Permian age and/or later may have resulted in large variations in salinity of the present oilfield waters with the lowest salinity formation waters in the palaeohighs.     

Who were the first urban settlers of Oslo? A discussion of early medieval urbanization based on isotopic analyses of human remains

This paper investigates the process of early urbanization in Oslo, Norway, during the initial period of early 11th–late 12th Century using a bioarchaeological approach. Through the use of isotope analyses performed on teeth and bone from 20 humans buried in Oslo during the first phases of urban settlement, individual dietary change and mobility are reconstructed. Oslo is traditionally perceived as one of many urban settlements initiated by royal power, and this paper contributes to this discussion by investigating the origin of the first settlers, and also how the early urban process affected their way of living. Results suggest that most individuals in the study were of local origin, and had a constant diet throughout life from childhood to its last phase. The absence of individual dietary change sharply contrasts the dynamic dietary patterns observed in people from the Viking age. Dietary variation between individuals does suggest, however, social differences among the early urban population of Oslo.     

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

The site of Conchopata in the central Peruvian Andes was the secondary center in the heartland of the Wari Empire (AD 600–1000), and in this study we examine whether this urban locale was populated by locals, voluntary migrants from distant regions, and/or captives who were forcibly brought to Conchopata. We examine radiogenic strontium isotope ratios from 72 dental enamel and bone samples representing 31 formal burials and 18 human trophy heads to distinguish between locals and non-locals, and we examine skeletal and archaeological data to establish whether non-local persons were voluntary migrants or captives. We also describe a new, straightforward technique in the evaluation of radiogenic strontium isotope ratios to assist in detecting non-locals when large datasets are available.Results show that natal Conchopata inhabitants should exhibit radiogenic strontium isotope ratios that range from ⁸⁷Sr/⁸⁶Sr = 0.70548 to ⁸⁷Sr/⁸⁶Sr = 0.70610. Thus, among the 31 burials, 29 exhibit local values, suggesting that Conchopata was not a cosmopolitan center to which numerous foreigners migrated; rather, it was populated by local peoples, likely the descendants of the preceding Huarpa culture. The two individuals with non-local radiogenic strontium isotope ratios are an infant and a 17–22 years old female. The archaeological context suggests that the female may have been taken captive for subsequent sacrifice, as she was interred in front of the ritual D-shaped structure in which decapitated human heads (trophy heads) and sacrificed camelids were deposited. Among the 18 trophy heads sampled, 14 have non-local values, confirming previous studies of smaller samples that suggested that Wari warriors travelled to other locales and took captives—both adults and children—for subsequent transformation into trophy heads. Additional analyses of bone-tooth pairs from a subsample (12 burials and six trophy heads) shows that the burial group was much more sedentary (homogenous radiogenic strontium isotope ratios in bones and teeth) and the trophy head individuals were much more mobile (heterogenous radiogenic strontium isotope ratios in bones and teeth). Overall, the multiple lines of evidence support the notion that the Wari Empire occasionally used militaristic means, combined with elaborate ritualism, to subjugate other populations, a tactic that may have helped Wari establish and maintain control in particular regions in the Andes.     

Pastoralist Mobility in Bronze Age Landscapes of Northern Kazakhstan: 87Sr/86Sr and δ18O Analyses of Human Dentition from Bestamak and Lisakovsk

ABSTRACT

The role of migration and mobility of people across the steppe has often been cited as key to Bronze Age developments across Eurasia, including the emergence of complex societies in the steppe and the spread of material culture. The central Eurasian steppe (CES) is a focal point for the investigation of the shifting nature of pastoral societies because of the clear transition in archaeological patterning that occurred from the Middle (MBA) to Late Bronze Age (LBA). The spread of LBA (1700–1400?cal BC) Andronovo cultural materials found across wide swaths of the steppe provide indirect evidence for broad scale interactions, but the degree to which people moved across the landscape remains poorly understood. This study takes a first step into documenting human movement during these critical periods through strontium (⁸⁷Sr/⁸⁶Sr) and oxygen (δ¹⁸O) isotopic analyses of tooth enamel recovered from human individuals buried in the cemeteries of Bestamak (MBA) and Lisakovsk (LBA) in northern Kazakhstan. Strontium isotope results, referenced against the distribution of contemporary bioavailable strontium in the vicinity of both sites, suggest local communities engaged in small-scale mobility with limited ranges. Reduced strontium and oxygen isotopic variation visible in humans from Lisakovsk suggests mobility decreased from the Middle to Late Bronze Age likely indicative of a shift in resource and landscape use over time.     

To live and let die: Food,famine, and administrative violence in Democratic Kampuchea, 1975–1979

Between 1975 and 1979 approximately two million people died in the Cambodian genocide. We argue that the mass violence that transpired during this period was a manifestation of the Khmer Rouge's attempt to make life. Through a focus on the production of both violence and vulnerability we direct attention to the contradictory policies and practices forwarded by the Khmer Rouge that were designed to maximize life through the maximization of death. Specifically, we consider the mass starvation that accompanied the genocide as a structure of violence; we forward the argument that the rationing of food constitutes a calculated yet contradictory policy, namely that food rations represent in material form an inner contradiction of fostering life and disallowing life. Subsequently, the policy of forced rations—which imposed a particular space of vulnerability on Cambodia's population—resulted in massive loss of life through starvation and disease that were not the unintended side-effects of poor research, poor planning, or poor implementation on behalf of the Khmer Rouge, but rather were the necessary consequences of a proto-capitalist form of state-building.