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Isotope Analysis (isotope + analysis)
Kinds of Isotope Analysis Selected AbstractsLEAD ISOTOPE ANALYSES OF BRONZE AGE COPPER-BASE ARTEFACTS FROM AL-MIDAMMAN, YEMEN: TOWARDS THE IDENTIFICATION OF AN INDIGENOUS METAL PRODUCTION AND EXCHANGE SYSTEM IN THE SOUTHERN RED SEA REGION,ARCHAEOMETRY, Issue 4 2009L. WEEKS The results of the lead isotope analysis (LIA) of 15 copper-base artefacts from the Bronze Age site of al-Midamman, Yemen, are reported. The LIA data suggest the existence of an indigenous Bronze Age metal production and exchange system centred on the southern Red Sea region, distinct from those in neighbouring regions of Arabia and the Levant. These preliminary results are highly significant for the archaeology of the region, suggesting that local prehistoric copper extraction sites have thus far gone unrecorded, and highlighting the need for systematic archaeometallurgical fieldwork programmes in the countries surrounding the southern Red Sea. [source] PETROGRAPHIC AND STABLE ISOTOPE ANALYSES OF LATE CLASSIC ULÚA MARBLE VASES AND POTENTIAL SOURCES*ARCHAEOMETRY, Issue 1 2006C. LUKE Ulúa marble vases from the Ulúa Valley of northwestern Honduras are a hallmark luxury good from Late Classic (ad 600,900) Mesoamerica. Archaeological and stylistic data point to centralized production at one site, Travesía. This paper analyses stable isotope and petrographic data from the vases and three potential procurement areas. The results indicate that the vases were produced from one primary source with one, potentially two, secondary sources. Procurement patterns most probably corresponded to contemporary communication routes. The results clearly indicate that a multi-method approach is necessary for sourcing marble from Honduras. [source] OXYGEN AND CARBON ISOTOPE ANALYSIS OF HUMAN TOOTH ENAMEL FROM THE NEW KINGDOM SITE OF TOMBOS IN NUBIAARCHAEOMETRY, Issue 5 2010M. R. BUZON This study examines the feasibility of using oxygen isotope analysis of tooth carbonate to identify immigrants from the New Kingdom site of Tombos in Nubia (n = 30). In comparison with published data, the results (,18Oca,VSMOW = 31.4,) imply a substantial presence of immigrants. However, further analysis of these data strongly suggests the need to consider hydrological and cultural factors such as the contribution of aquifer waters to the Nile, use of groundwater sources, and differences in handling and storage of water. The carbon isotope analysis, in conjunction with published 87Sr/86Sr data, provides additional support for the presence of immigrants at Tombos. [source] LEAD ISOTOPE ANALYSIS OF TANG SANCAI POTTERY GLAZES FROM GONGYI KILN, HENAN PROVINCE AND HUANGBAO KILN, SHAANXI PROVINCEARCHAEOMETRY, Issue 4 2010J. F. CUI Through the use of MC,ICP,MS, this study analyses the lead isotope ratios of 19 Tang Sancai pottery glazes unearthed from the Gongyi and Huangbao kiln sites. According to their different lead isotope ratios, the two kilns can be grouped separately. The research also suggests that the Gongyi and Huangbao kilns are independent production centres of Tang Sancai in the Tang Dynasty. The data from the Huangbao kiln indicates that the lead in the glazes originates from the Northern China geochemical province, while the data from Gongyi kiln suggests its source as the Yangtze geochemical province. Furthermore, the results obtained for the Tang Sancai pottery indicate that the lead sources for glaze making of these two kilns were very consistent, which suggests that lead isotope analysis could be a helpful method to identify the kilns producing Tang Sancai artefacts. [source] Individual responses of seabirds to commercial fisheries revealed using GPS tracking, stable isotopes and vessel monitoring systemsJOURNAL OF APPLIED ECOLOGY, Issue 2 2010Stephen C. Votier Summary 1.,The large amount of discards produced by commercial fisheries can have major impacts on marine predator populations: this abundant food may increase populations of some scavengers or decrease others via accidental bycatch. Yet, despite the conservation implications of discard practices, the ecology of individual scavengers is poorly understood. 2.,Here, we assess the influence of commercial fisheries' activity on the foraging behaviour of individual breeding northern gannets Morus bassanus. Using recent developments in stable isotope mixing models (Stable Isotope Analysis in R or SIAR) we estimate individual discard consumption. Using GPS tracking and the Vessel Monitoring System (VMS), we investigate behavioural responses to trawlers. 3.,Analysis of conventional diet samples, as well as stable isotope ratios of carbon and nitrogen in blood (plasma and cells), highlight marked individual differences in the proportion of fishery discards in the diet. Individual differences in foraging behaviour revealed by stable isotopes show evidence of both short-term consistency and behavioural flexibility. 4.,At-sea path tortuosity of 25 gannets (tracked using GPS loggers) revealed scale-dependent adjustments in response to VMS-derived fishing vessel locations, as well as to sea surface temperature, chlorophyll a concentration and copepod abundance. The results also indicate individual variability in behavioural response to trawlers. 5.,Individual differences in the amount of discards estimated from SIAR were negatively correlated with differences in foraging trip length and body condition, indicating potential fitness consequences. 6.,Synthesis and applications. The management of commercial fisheries and apex predators is a daunting task. Ultimately, reducing bycatch and removing dependency on discards remain key conservation priorities, but managers should also ensure that scavenging species have sufficient alternative food to meet their energetic needs, to ameliorate potential unforeseen knock-on consequences. The results of Stable Isotope Analysis (SIAR) reveal intra-population differences in discard consumption by gannets; differences that have impacts on foraging effort and body condition. The use of GPS tracking and Vessel Monitoring Systems (VMS) reveal that gannet at-sea behaviour is influenced by fishing vessels, although this also varies among individuals. A combination of SIAR, GPS tracking and VMS can be used to study fishery/scavenger interactions in detail at the individual level, to answer fundamental questions about scavenging behaviour. [source] The Use of Strontium Isotope Analysis to Investigate Tiwanaku Migration and Mortuary Ritual in Bolivia and PeruARCHAEOMETRY, Issue 1 2004K. J. Knudson Strontium isotope analysis is applied in South America for the first time in order to investigate residential mobility and mortuary ritual from ad 500 to 1000. While Tiwanaku-style artefacts are spread throughout Bolivia, southern Peru and northern Chile during this time, the nature of Tiwanaku influence in the region is much debated. Human skeletal remains from the site of Tiwanaku and the proposed Tiwanaku colony of Chen Chen have been analysed to test the hypothesis that Tiwanaku colonies, populated with inhabitants from Tiwanaku, existed in Peru. Strontium isotope analysis supports this hypothesis by demonstrating that non-local individuals are present at both sites. [source] Methods to adjust for the interference of N2O on ,13C and ,18O measurements of CO2 from soil mineralization,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2005D. Beheydt In this paper we present an overview of the present knowledge relating to methods that avoid interference of N2O on ,13C and ,18O measurements of CO2. The main focus of research to date has been on atmospheric samples. However, N2O is predominantly generated by soil processes. Isotope analyses related to soil trace gas emissions are often performed with continuous flow isotope ratio mass spectrometers, which do not necessarily have the high precision needed for atmospheric research. However, it was shown by using laboratory and field samples that a correction to obtain reliable ,13C and ,18O values is also required for a commercial continuous flow isotope ratio mass spectrometer. The capillary gas chromatography column of the original equipment was changed to a packed Porapak Q column. This adaptation resulted in an improved accuracy and precision of ,13C (standard deviationGhent: from 0.2 to 0.08,; standard deviationLincoln: from 0.2 to 0.13,) of CO2 for N2O/CO2 ratios up to 0.1. For ,18O there was an improvement for the standard deviation measured at Ghent University (0.13 to 0.08,) but not for the measurements at Lincoln University (0.08 to 0.23,). The benefits of using the packed Porapak Q column compared with the theoretical correction method meant that samples were not limited to small N2O concentrations, they did not require an extra N2O concentration measurement, and measurements were independent of the variable isotopic composition of N2O from soil. Copyright © 2005 John Wiley & Sons, Ltd. [source] Isotope analysis of hydrocarbons: trapping, recovering and archiving hydrocarbons and halocarbons separated from ambient airRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 4 2005M. Pupek It is argued that isotope analysis of atmospheric non-methane hydrocarbons (NMHCs) and, in particular, the analysis of the deuterium/hydrogen (D/H) ratio is valuable because the dominant self-cleansing property of the troposphere is based on the OH radical which removes, e.g., CH4 and other alkanes by H-atom abstraction, which induces large kinetic isotope effects. The major obstacle in applying D/H isotope analysis to atmospheric NMHCs is not only the low abundance of D itself but, in particular, the low concentrations of NMHCs in the parts per trillion range. We show how a selection of NMHCs can be quantitatively separated from 300,L air samples together with CO2 as carrier gas matrix, by using high efficiency cryogenic traps. After diluting the extracted NMHC mixtures with hydrocarbon free air, and determining the mixing ratios, good agreement with original whole air sample analysis exists for alkanes and several halocarbons. For unsaturated hydrocarbons and some other halocarbons the extraction and recovery yield under the given conditions fell considerably, as a function of boiling point. Furthermore, the mixture of NMHCs in the CO2 matrix is proven to remain unchanged over several years when conveniently stored in glass ampoules. The ,extracts' or ,concentrates' of condensables extracted from larger air samples will enable the D/H isotope analysis of ultra trace gases in the atmosphere. Copyright © 2005 John Wiley & Sons, Ltd. [source] Feather deuterium measurements reveal origins of migratory western loggerhead shrikes (Lanius ludovicianus excubitorides) wintering in MexicoDIVERSITY AND DISTRIBUTIONS, Issue 2 2007Guillermo E. Pérez ABSTRACT Understanding the winter distributions of migrant birds is important because productivity and recruitment are influenced by conditions at several locations and periods in the life cycle of individuals. The western loggerhead shrike, Lanius ludovicianus excubitorides, is a threatened species in Canada, and its decline is attributed to potential limitations on the wintering grounds. We examined patterns of stable-hydrogen isotope (,D) distributions in feathers of loggerhead shrikes, primarily of L. l. excubitorides, during winter at three regions in north and central Mexico, to establish relative abundance and origins of migrants. We also investigated potential movements of Mexican winter resident individuals. Using shrike museum specimens of known summer provenance, a shrike deuterium base map for Mexico was developed from isotopic measurement of feathers of resident shrikes and use of a recently established feather base map for raptors in North America. Stable hydrogen isotope analyses of inner secondary feather (s9) of all loggerhead shrikes examined in Mexico during winter indicated that north-central (Region A), north-eastern (Region B) and south-central (Region C) sites in Mexico consisted of 28.1%, 73.7% and 63.8% of migrant individuals from northern breeding grounds, respectively. Isotopic evidence suggested movements of a few local residents birds (7.9%) into the Chihuahuan desert from south-western USA and north-eastern Mexico to winter. [source] Below-ground competition between trees and grasses may overwhelm the facilitative effects of hydraulic liftECOLOGY LETTERS, Issue 8 2004F. Ludwig Abstract Under large East African Acacia trees, which were known to show hydraulic lift, we experimentally tested whether tree roots facilitate grass production or compete with grasses for below-ground resources. Prevention of tree,grass interactions through root trenching led to increased soil water content indicating that trees took up more water from the topsoil than they exuded via hydraulic lift. Biomass was higher in trenched plots compared to controls probably because of reduced competition for water. Stable isotope analyses of plant and source water showed that grasses which competed with trees used a greater proportion of deep water compared with grasses in trenched plots. Grasses therefore used hydraulically lifted water provided by trees, or took up deep soil water directly by growing deeper roots when competition with trees occurred. We conclude that any facilitative effect of hydraulic lift for neighbouring species may easily be overwhelmed by water competition in (semi-) arid regions. [source] Effects of lipid extraction on stable carbon and nitrogen isotope analyses of fish tissues: potential consequences for food web studiesECOLOGY OF FRESHWATER FISH, Issue 3 2004M. A. Sotiropoulos Abstract,,, We examined whether solvent-based lipid extractions, commonly used for stable isotope analysis (SIA) of biota, alters ,15N or ,13C values of fish muscle tissue or whole juvenile fish. Lipid extraction from muscle tissue led to only small (<1,) isotope shifts in ,13C and ,15N values. By contrast, ecologically significant shifts (+3.4, for ,13C and +2.8, for ,15N) were observed for whole juvenile fish. Sample variance was not affected by lipid extraction. For tissue-specific SIA, two sample aliquots may be required: a lipid-extracted aliquot for stable carbon isotope analysis when differing lipid content among tissues is a concern, and a nonextracted aliquot for ,15N determination. Whole organism SIA is not recommended because of the mix of tissues having different turnover times; for very small fish, we recommend that fish be eviscerated, decapitated, and skinned to minimise differences with samples of muscle tissue. Resumen 1. Cada vez con mayor frecuencia, los ecólogos de peces utilizan análisis de isótopos estables. Por ello, se hace cada vez más importante comprender las fuentes de variación, - debido a diferencias inherentes entre muestreos biológicos o como resultado de técnicas de procesamiento de muestreo - tanto como identificar estrategias para tratar tales fuentes. Examinamos si la extracción de lípidos basada en disolventes, comúnmente utilizada en análisis de isótopos de carbono estable, altera negativamente los valores de ,15N y ,13C de tejido muscular de tres peces de tamaño pequeño y de peces juveniles completos. 2. La extracción de lípidos de músculo de pez llevó a pequeños cambios isotópicos de + +0.4 a +1.0, y de +0.3 a +0.5, para ,13C y ,15N, respectivamente. Por el contrario, la extracción de lípidos de peces juveniles completos varió marcadamente en +3.4, para ,13C y +2.8, para ,15N - ambos cambios ecológicamente importantes. La varianza de los valores de muestreos de ,13C y de ,15N tanto para tejido muscular como para los peces completos no difirieron entre los muestreos de lípidos extraídos y muestreos sin tratamiento. 3. Nuestros resultados recomiendan el análisis de isótopos estables de tejidos específicos. Cuando ello no es posible o deseable, dos alícuotas de muestreo pueden ser requeridas: una alícuota de lípidos extraídos para el análisis de isótopos de carbono estable cuando la varianza de ,13C, debida a diferencias en el contenido de lípidos de diferentes tejidos, y una alícuota de no-extracción para determinaciones de ,15N. 4. Dada la mezcla de tejidos, el análisis de isótopos de un organismo completo no es recomendable , en el caso de peces muy pequeños, recomendamos que los peces sean eviscerados, decapitados, y despellejados para minimizar las diferencias de muestreos de tejido muscular. [source] Increased growth and recruitment of piscivorous perch, Perca fluviatilis, during a transient phase of expanding submerged vegetation in a shallow lakeFRESHWATER BIOLOGY, Issue 12 2005ANDERS HARGEBY Summary 1. In this study, we examine how a 7-year period of expanding submerged stonewort (Chara spp.) vegetation during a shift from turbid to clear water in a shallow lake influenced individual growth and population size structure of perch (Perca fluviatilis). We expected that a shift from phytoplankton to macrophyte dominance and clear water would improve feeding conditions for perch during a critical benthivorous ontogenetic stage, and enhance the recruitment of piscivorous perch. 2. Growth analysis based on opercula showed that growth during the second year of life was significantly higher in years with abundant vegetation than in years with turbid water and sparse vegetation. Growth was not affected during the first, third and fourth year of life. Stable isotope analyses on opercula from 2-year-old perch showed that the increase in growth coincided with a change in carbon source in the diet. Stable nitrogen ratio did not change, indicating that the increased growth was not an effect of any change in trophic position. 3. Following the expansion of submerged vegetation, perch size range and abundance of piscivorous perch increased in central, unvegetated areas of the lake. In stands of stoneworts, however, mainly benthivorous perch were caught, and size range did not change with time. 4. Our findings provide empirical support for the notion that establishment of submerged vegetation may lead to increased recruitment of piscivorous perch, because of improved competitive conditions for perch during the benthivorous stage. This is likely to constitute a benthic-pelagic feedback coupling, in which submerged vegetation and clear water promote the recruitment of piscivorous perch, which, in turn, may increase water clarity through top-down effects in the pelagic. [source] Ferox Trout (Salmo trutta) as `Russian dolls': complementary gut content and stable isotope analyses of the Loch Ness foodwebFRESHWATER BIOLOGY, Issue 7 2002J. GREY 1.,Conventional collection methods for pelagic fish species (netting, trawling) are impractical or prohibited in Loch Ness, U.K. To investigate trophic relationships at the top of the Loch Ness food web, an alternative strategy, angling, provided samples of the top predator, the purely piscivorous ferox trout (Salmo trutta). 2.,The gut contents of these fish provided further samples of prey-fish, and subsequent examination of prey-fish guts revealed their dietary intake, analogous to the famous nested `Russian dolls'. Each trophic level separated by gut content analysis provided further complementary samples for stable isotope analysis and thus information on the longer term, assimilated diet. 3.,Ferox trout exhibited considerable cannibalism to supplement a diet of Arctic charr (Salvelinus alpinus). However, conspecifics stemmed from a lower isotopic baseline in relation to charr, so ferox trout exhibited a lower trophic level than predicted (4.3) by using the ,15N values. Charr displayed dietary specialisation with increasing length, and isotopic values supported by the gut data placed the charr at a trophic level of 3.5. The isotope data also indicated that charr carbon was primarily autochthonous in origin. [source] Sulphur isotopes and the search for life: strategies for identifying sulphur metabolisms in the rock record and beyondGEOBIOLOGY, Issue 5 2008D. T. JOHNSTON ABSTRACT The search for life can only be as successful as our understanding of the tools we use to search for it. Here we present new sulphur isotope data (32S, 33S, 34S, 36S) from a variety of modern marine environments and use these observations, along with previously published work, to contribute to this search. Specifically, we use these new data to gain a sense of life's influences on the sulphur isotope record and to distinguish these biologically influenced signatures from their non-biological counterparts. This treatment extends sulphur isotope analyses beyond traditional (34S/32S) measures and employs trace isotope relationships (33S/32S, 36S/32S), as the inclusion of these isotopes provides unique information about biology and its role in the sulphur cycle through time. In the current study we compare and contrast isotope effects produced by sulphur-utilizing microorganisms (experimental), modern and ancient sedimentary records (observational) and non-biological reactions (theoretical). With our collective search for life now extending to neighbouring planets, we present this study as a first step towards more fully understanding the capability of the sulphur isotope system as a viable tool for life detection, both on Earth and beyond. [source] Geothermal prognoses for tunnels in the Andes / . Geothermische Prognose für AndentunnelGEOMECHANICS AND TUNNELLING, Issue 5 2010Mag. Giorgio Höfer-Öllinger Geothermal energy - Geothermie; Reconnaissance - Baugrunderkundung; Hydrology - Hydrologie; Geology - Geologie Abstract Geothermal prognoses were carried out for two tunnel projects in the Andes, each running between Argentina and Chile. Different methods were applied in accordance with the different project phases. For the feasibility study of a 52 km long railway tunnel, hydrogeological mapping and hydrochemical analyses were carried out as well as isotope analyses on a thermal spring. An attempt to use silica and ionic solute geothermometers produced different results. For the central section of the tunnel temperatures are assumed to reach 50 to 70 °C and further investigations are recommended. The second tunnel project is now in the design phase. Two investigation phases have been completed including geological/ hydrogeological mapping, water sampling and analysis and core drilling. The geothermal gradient is well known from borehole temperature measurements. The thermal conductivity of the rocks was determined from core samples in a laboratory, and an average heat flow of approximately 100 mW/m2 was calculated. During the driving of the tunnel, temperatures of just over 50 °C are expected. Für zwei Tunnelvorhaben in den Anden, jeweils zwischen Argentinien und Chile, wurden geothermische Prognosen durchgeführt. Für verschiedene Projektphasen kamen entsprechend unterschiedliche Methoden zur Anwendung: Für eine Machbarkeitsstudie eines 52 km langen Eisenbahntunnels wurde eine Quellkartierung mit Probennahme durchgeführt sowie Isotopenanalytik an einer Thermalquelle. Ein Versuch, Geothermometer anhand der Lösungsfracht des Quellwassers zu verwenden, scheiterte. Für den zentralen Bereich des Tunnels werden Temperaturen von 50 bis 70 °C vermutet, weitere Erkundungen wurden empfohlen. Das zweite Tunnelvorhaben ist in der Planungsphase deutlich weiter. Neben Kartierungen liegen zwei Erkundungsphasen mit Kernbohrungen vor. Aus Bohrlochmessungen ist der geothermische Gradient bekannt, die Wärmeleitfähigkeit der Gesteine wurde anhand von Bohrkernen im Labor ermittelt. Es konnte ein durchschnittlicher Wärmefluss von etwa 100 mW/m2 errechnet werden, für den Tunnelvortrieb werden Gebirgstemperaturen von maximal knapp über 50 °C erwartet. [source] Development of Saline Ground Water through Transpiration of Sea WaterGROUND WATER, Issue 6 2007T. Fass As vegetation usually excludes salt during water uptake, transpiration will increase the salinity of the residual water. If the source water is sea water, then the residual water may become highly saline. In the unconfined coastal aquifer of the tropical Burdekin River delta, northeastern Australia, areas of highly saline ground water with chloride concentrations up to almost three times that of sea water occur up to 15 km from the present coastline, and are attributed to transpiration by mangrove vegetation during periods of high sea level. Radiogenic (14C) carbon isotope analyses indicate that ground water with chloride concentrations between 15,000 and 35,000 mg/L is mostly between 4000 and 6000 years old, at which time sea level was 2 to 3 m higher than present. Stable isotope analyses of oxygen-18 and deuterium show no evidence for evaporative enrichment of this water. Oxygen-18, deuterium, and stable (,13C) carbon isotope analyses of ground water and soil water point to a recharge environment beneath the mangrove forests during this postglacial sea level high stand. During that period, transpiration of the mangrove forests would have led to high chloride concentrations in the residual ground water, without inducing isotopic fractionation. Due to the higher density, this hypersaline water moved downward through the aquifer by gravity and has formed lenses of highly saline ground water at the bottom of the unconfined aquifer. [source] Characterization and Origin of Dissolved Organic Carbon in Yegua Ground Water in Brazos County, TexasGROUND WATER, Issue 5 2001Joyanto Routh Dissolved organic carbon (DOC) concentrations in five shallow (< 20 m) and three deeper wells (27 to 30 m) in the Eocene Yegua Formation (Brazos County in east-central Texas) ranged from 92 to 500 ,m. Characterization of high, intermediate, and low molecular weight DOC fractions (HMW > 3000 amu, IMW 1000 to 3000 amu, and LMW 500 to 1000 amu) and combined neutral sugar analyses provide information on organic matter sources in the Yegua aquifers. Combined neutral sugars ranged in concentration from 0.6 to 2.7 ,mol/L and comprised 0.8% to 6.7% of DOC in ground water. Glucose was the most abundant neutral sugar, followed by xylose and galactose, arabinose, mannose, rhamnose, and fucose. These combined neutral sugars were more diagenetically altered in shallow, oxic ground water as indicated by high mole % fucose + rhamnose and low neutral sugar yield. The precursors for neutral sugars are most probably angiosperm leaves, which show a similar distribution pattern of neutral sugars. Ground water DOC was depleted in 13C relative to soil-zone organic matter (OM) (,16, to ,19,). The ,13C values of bulk DOC and HMW DOC ranged from ,24, to ,32,, whereas LMW and IMW DOC ranged from ,32, to ,34, and ,16, to ,28,, respectively. This variability in ,13C values is probably related to microbial processes and selective preservation of OM. Carbon isotope analyses in bulk and different molecular weight DOC fractions imply a predominantly C3 OM source and a low contribution of soil-zone OM to DOC. [source] Applications of stable isotope analyses to avian ecologyIBIS, Issue 3 2008RICHARD INGER In the past 20 years the use of stable isotope analysis has become increasingly common in ecological studies. In fact, in some instances these techniques have yielded remarkable insights into the foraging preferences and migrations of birds. Despite these advances and the potential of the approach, it is possibly still not as widely used as might be expected. In this paper we aim to illustrate the potential of the approach in the hope of encouraging more avian ecologists to think again about how these techniques might provide insights in the systems on which they work. We discuss some of the principles behind the approach, and review some of the more recent ornithological studies that have used stable isotope techniques to trace trophic pathways or infer migratory origins. We follow this by discussing some of the latest ideas on how stable isotopes may be used to generate community metrics and close by detailing the important assumptions and caveats that should be considered before undertaking any studies using this technique. [source] A Late Neolithic vertebrate food web based on stable isotope analysesINTERNATIONAL JOURNAL OF OSTEOARCHAEOLOGY, Issue 4 2006C. Bösl Abstract Stable carbon and nitrogen isotope analyses of bone collagen, and stable carbon and oxygen isotope analyses of the bone's structural carbonate, were performed on 120 individuals representing 33 vertebrate species, including a single human bone find, collected from the Late Neolithic settlement at Pestenacker, Bavaria, Germany. We were thus capable of reconstructing a rather complex food web and could also address particular issues, such as whether humans influenced the diet of their domestic animals as opposed to their wild relatives, or whether humans perhaps had to compete over food with their domesticates. A rather unexpected result was that freshwater fish, which could be captured in the nearby river Lech, a major tributary of the Danube, contributed to the human diet only occasionally. As for mammals, it was also possible to recognise different trophic levels for birds and aquatic vertebrates, applying stable isotope analyses to both bone collagen and structural carbonate. In the case of fish, ,18O values at least revealed a physiological regularity in terms of temperature preference, besides diet. Conceivably, variability of ,18O in surface water as reflected, for example, by species that avoided human settlements, may help to characterise past ecosystems and to define site catchment exploited by Neolithic man in the course of food acquisition. Copyright © 2006 John Wiley & Sons, Ltd. [source] Interactions between serpentinite devolatilization, metasomatism and strike-slip strain localization during deep-crustal shearing in the Eastern AlpsJOURNAL OF METAMORPHIC GEOLOGY, Issue 4 2004J. D. Barnes Abstract The Greiner shear zone in the Tauern Window, Eastern Alps, changes from a zone of distributed (dominantly sinistral) shear in supracrustal rocks to a series of narrow, gully forming dextral splays where it enters basement gneisses. Within these splays, granodiorite is transformed into quartz-poor biotite and/or chlorite schists, reflecting hydration, removal of Si, Ca and Na, and concentration of Fe, Mg and Al. Stable isotope analyses show a prominent increase in ,D and a decrease in ,18O from granodiorite into the shear zones. These changes indicate significant channelized flow of an externally derived, low-,18O, high-,D fluid through the shear zones. The shear zone schists are chemically similar to blackwall zones developed around serpentinite bodies elsewhere in the Greiner zone and the stable isotope data support alteration via serpentinite-derived fluid. Monazite in schist from one shear zone yields spot dates of 29,20 Ma, indicating that the fluid influx and switch from sinistral to dextral shear occurred at or shortly after the thermal peak of the Alpine orogeny (c. 30 Ma). We suggest that Alpine metamorphism of serpentinites released large amounts of high-,D, low-,18O, Si-undersaturated, Fe + Mg-saturated fluids that became channelized along prior zones of weakness in the granodiorite. Infiltration of this fluid facilitated growth of chlorite and biotite, which in turn localized later dextral strain in the narrow splays via cleavage-parallel slip. This dextral strain event can be linked to other structures that accommodated tectonic escape of major crustal blocks during dextral transpression in the Eastern Alps. This study shows that serpentinite devolatilization can play an important role in modifying both the chemistry and rheology of surrounding rocks during orogenesis. [source] HYDROTHERMALLY FLUORITIZED ORDOVICIAN CARBONATES AS RESERVOIR ROCKS IN THE TAZHONG AREA, CENTRALTARIM BASIN, NW CHINAJOURNAL OF PETROLEUM GEOLOGY, Issue 1 2006Zhijun Jin Reservoir rocks at the Tazhong 45 oil pool, central Tarim Basin, consist of fluoritized carbonate strata of Middle - Late Ordovician age. Petrological observations indicate that the fluorite replaces calcite. Several other hydrothermal minerals including pyrite, quartz, sphalerite and chlorite accompany the fluorite. Two generations of fluid inclusions are present in the fluorite. Homogenization temperatures (Th) for primary inclusions are mostly between 260°C and 310°C and represent the temperature of the hydrothermal fluid responsible for fluorite precipitation. Th for secondary inclusions range from 100°C to 130°C, and represent the hydrocarbon charging temperature as shown by the presence of hydrocarbons trapped in some secondary inclusions. The mineral assemblage and the homogenization temperatures of the primary fluid inclusions indicate that the precipitation of fluorite is related to hydrothermal activity in the Tazhong area. Strontium isotope analyses imply that the hydrothermal fluids responsible for fluorite precipitation are related to late-stage magmatic activity, and felsic magmas were generated by mixing of mafic magma and crustal materials during the Permian. Theoretical calculations show that the molecular volume of a carbonate rock decreases by 33.5% when calcite is replaced by fluorite, and the volume shrinkage can greatly enhance reservoir porosity by the formation of abundant intercrystalline pores. Fluoritization has thus greatly enhanced the reservoir quality of Ordovician carbonates in the Tazhong 45 area, so that the fluorite and limestone host rocks have become an efficient hydrocarbon reservoir. According to the modelled burial and thermal history of the Tazhong 45 well, and the homogenization temperatures of secondary fluid inclusions in the fluorite, hydrocarbon charging at the Tazhong 45 reservoir took place in the Tertiary. [source] Ice caps existed throughout the Lateglacial Interstadial in northern Scotland,JOURNAL OF QUATERNARY SCIENCE, Issue 5 2008Tom Bradwell Abstract We constrain, in detail, fluctuations of two former ice caps in NW Scotland with multibeam seabed surveys, geomorphological mapping and cosmogenic 10Be isotope analyses. We map a continuous sequence of 40 recessional moraines stretching from ,10,km offshore to the Wester Ross mountains. Surface-exposure ages from boulders on moraine ridges in Assynt and the Summer Isles region show that substantial, dynamic, ice caps existed in NW Scotland between 13 and 14,ka BP. We interpret this as strong evidence that large active glaciers probably survived throughout the Lateglacial Interstadial, and that during the Older Dryas period (ca. 14,ka BP) ice caps in NW Scotland were thicker and considerably more extensive than in the subsequent Younger Dryas Stadial. By inference, we suggest that Lateglacial ice-cap oscillations in Scotland reflect the complex interplay between changing temperature and precipitation regimes during this climatically unstable period (ca. 15,11,ka BP). © Natural Environment Research Council (NERC) copyright 2008. Reproduced with the permission of NERC. Published by John Wiley & Sons, Ltd. [source] ECOSYSTEM DYNAMICS AND POLLUTION EFFECTS IN AN OZARK CAVE STREAM,JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION, Issue 6 2003Gary O. Graening ABSTRACT: Subterranean ecosystems harbor globally rare fauna and important water resources, but ecological processes are poorly understood and are threatened by anthropogenic stresses. Ecosystem analyses were conducted from 1997 to 2000 in Cave Springs Cave, Arkansas, situated in a region of intensive land use, to determine the degree of habitat degradation and viability of endangered fauna. Organic matter budgeting quantified energy flux and documented the dominant input as dissolved organic matter and not gray bat guano (Myotis grisescens). Carbon/nitrogen stable isotope analyses described a trophic web of Ozark cavefish (Amblyopsis rosae) that primarily consumed cave isopods (Caecidotea stiladactyla), which in turn appeared to consume benthic matter originating from a complex mixture of soil, leaf litter, and anthropogenic wastes. Septic leachate, sewage sludge, and cow manure were suspected to augment the food web and were implicated in environmental degradation. Water, sediment, and animal tissue analyses detected excess nutrients, fecal bacteria, and toxic concentrations of metals. Community assemblage may have been altered: sensitive species-grotto salamanders (Typhlotriton spelaeus) and stygobro-mid amphipods,were not detected, while more resilient isopods flourished. Reduction of septic and agricultural waste inputs may be necessary to restore ecosystem dynamics in this cave ecosystem to its former undisturbed condition. [source] Clearwater East impact structure: A re-interpretation of the projectile type using new platinum-group element data from meteoritesMETEORITICS & PLANETARY SCIENCE, Issue 3 2002Iain McDonald This is at odds with recent chromium isotope analyses that suggest ordinary chondrite-type material is present. The present study reviews and reinterprets the available PGE data in the light of new PGE data from meteorites and concludes that the PGE ratios in the impact melt are most consistent with ordinary (possibly type-L) chondrite source material, not carbonaceous chondrites. Therefore the structure was most probably formed by the impact of an asteroid composed of material similar to ordinary chondrites. [source] Carbon source accounting for fish using combined DNA and stable isotope analyses in a regulated lowland river weir poolMOLECULAR ECOLOGY, Issue 1 2010CHRISTOPHER M. HARDY Abstract Determining the source and flow of carbon, energy and nutrients through food webs is essential for understanding ecological connectivity and thus determining the impact of management practices on biodiversity. We combined DNA sequencing, microarrays and stable isotope analyses to test whether this approach would allow us to resolve the carbon flows through food webs in a weir pool on the lower Murray River, a highly impacted, complex and regulated ecosystem in southern Australia. We demonstrate that small fish in the Murray River consume a wide range of food items, but that a significant component of carbon and nitrogen entering the food web during dry periods in summer, but not spring, is derived from nonconventional sources other than in-channel primary producers. This study also showed that isotopic analyses alone cannot distinguish food sources and that a combined approach is better able to elucidate food-consumer dynamics. Our results highlight that a major river ecosystem, stressed by reduced environmental flows, can rapidly undergo significant and previously undetected changes that impact on the ecology of the system as a whole. [source] Seasonal variation in terrestrial resource subsidies influences trophic niche width and overlap in two aquatic snake species: a stable isotope approachOIKOS, Issue 7 2010John D. Willson Quantifying diet is essential for understanding the functional role of species with regard to energy processing, transfer, and storage within ecosystems. Recently, variance structure in the stable isotope composition of consumer tissues has been touted as a robust tool for quantifying trophic niche width, a task that has previously proven difficult due to bias in direct dietary analyses and difficulties in integrating diet composition over time. We used carbon and nitrogen stable isotope analyses to examine trophic niche width of two sympatric aquatic snakes, banded watersnakes Nerodia fasciata and black swamp snakes Seminatrix pygaea inhabiting an isolated wetland where seasonal migrations of amphibian prey cause dramatic shifts in resource availability. Specifically, we characterized snake and prey isotope compositions through time, space, and ontogeny and examined isotope values in relation to prey availability and snake diets assessed by gut content analysis. We determined that prey cluster into functional groups based on similarity of isotopic composition and seasonal availability. Isotope variance structure indicated that the trophic niche width of the banded watersnake was broader (more generalist) than that of the black swamp snake. Banded watersnakes also exhibited seasonal variation in isotope composition, suggesting seasonal diet shifts that track amphibian prey availability. Conversely, black swamp snakes exhibited little seasonal variation but displayed strong ontogenetic shifts in carbon and nitrogen isotope composition that closely paralleled ontogenetic shifts in their primary prey, paedomorphic mole salamanders Ambystoma talpoideum. Although niche dimensions are often treated as static, our results demonstrate that seasonal shifts in niche dimensions can lead to changes in niche overlap between sympatric species. Such short-term fluctuations in niche overlap can influence competitive interactions and consequently the composition and dynamics of communities and ecosystems. [source] Palaeoclimate reconstruction on Big Lyakhovsky Island, north Siberia,hydrogen and oxygen isotopes in ice wedgesPERMAFROST AND PERIGLACIAL PROCESSES, Issue 2 2002Hanno Meyer Abstract Late Quaternary permafrost deposits on Big Lyakhovsky Island (New Siberian Islands, Russian Arctic) were studied with the aim of reconstructing the palaeoclimatic and palaeoenvironmental conditions of northern Siberia. Hydrogen and oxygen stable isotope analyses are presented for six different generations of ice wedges as well as for recent ice wedges and precipitation. An age of about 200 ka BP was determined for an autochtonous peat layer in ice-rich deposits by U/Th method, containing the oldest ice wedges ever analysed for hydrogen and oxygen isotopes. The palaeoclimatic reconstruction revealed a period of severe winter temperatures at that time. After a gap in the sedimentation history of several tens of thousands of years, ice-wedge growth was re-initiated around 50 ka BP by a short period of extremely cold winters and rapid sedimentation leading to ice-wedge burial and characteristic ice-soil wedges (,polosatics'). This corresponds to the initial stage for the Late Weichselian Ice Complex, a peculiar cryolithogenic periglacial formation typical of the lowlands of northern Siberia. The Ice Complex ice wedges reflect cold winters and similar climatic conditions as around 200 ka BP. With a sharp rise in ,18O of 6, and ,D of 40,, the warming trend between Pleistocene and Holocene ice wedges is documented. Stable isotope data of recent ice wedges show that Big Lyakhovsky Island has never been as warm in winter as today. Copyright © 2002 John Wiley & Sons, Ltd. [source] Isotopic evidence of dietary variations and weaning practices in the Gaya cemetery at Yeanri, Gimhae, South KoreaAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2010Kyungcheol Choy Abstract Stable carbon and nitrogen isotope analyses were conducted to investigate dietary variation in human skeletons (n = 109) from the Gaya cemetery at Yeanri located near Gimhae City, South Korea. The cemetery contained three distinct grave types dating to 4th,7th century AD. The main purposes of this research were to reconstruct palaeodiet in the Gaya population and to explore correlations between stable isotope compositions and burial types, inferred age, and sex of these individuals. The isotopic data indicate that the people at Yeanri consumed a predominantly C3 -based terrestrial diet supplemented with freshwater and/or marine resources. The comparison of isotopic results reveals significant differences in ,13C values among three adult burial types (wood-cist coffin: ,18.5 ± 0.5,, stone-cist coffin: ,18.1 ± 0.6,, mausoleum: ,17.8 ± 0.9,). Males in wood-cist and stone-cist coffins have relatively more elevated mean ,13C and ,15N values than females. The isotopic ratios from the two adult age groups (21,40 years and 40,60 years) indicate that there was no significant dietary change in individuals with age. The isotope data from the infants and children suggest the weaning was a gradual process that was completed between 3 and 4 years of age in the Gaya population. This evidence indicates that the dietary variations within the cemetery reflect social status, sex, and childhood consumption patterns. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source] Migration to the Medieval Middle East with the CrusadesAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Piers D. Mitchell Abstract During the 12th and 13th centuries thousands of people moved from Europe to the Middle East to fight, undertake pilgrimage, or settle and make a new life. The aim of this research is to investigate two populations from the Crusader kingdom of Jerusalem, by determining who was born in Europe and who came from the Middle East. Oxygen and strontium stable isotope analyses were conducted on the enamel of teeth from skeletal remains excavated from Crusader contexts. Twenty individuals from the coastal city of Caesarea (10 high status and 10 low status), and two local Near Eastern Christian farmers from the village of Parvum Gerinum (Tel Jezreel) were analyzed as a control sample. Results were compared with known geographic values for oxygen and strontium isotopes. The population of the city of Caesarea appears to have been dominated by European-born individuals (probably 19/20, but at least 13/20), with few locals. This was surprising as a much higher proportion of locals were expected. Both controls from the farming village of Parvum Gerinum had spent their childhood in the area of the village, which matches our understanding of limited mobility among poor Medieval farmers. This is the first time that stable isotope analysis has been applied to the study of the migration of peoples between Medieval Europe and the Middle East at the time of the crusades. In view of these findings, we must now rethink past estimations of population social structure in Levantine coastal Medieval cities during the Crusader period. Am J Phys Anthropol 2009. © 2009 Wiley-Liss, Inc. [source] Geographic origin of southern Brazilian wines by carbon and oxygen isotope analysesRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 20 2010Laurien Adami We present a method that can differentiate between the varieties of grapes and the vintages of wines and show the relationship between the grapes, the wine and the geographic location. The place of origin and its geographic and climatic characteristics were determined by the isotopic ratios, 13C/12C of the ethanol and 18O/16O of the water content of wine (wine water), for southern Brazil wines. The producing subregions of Pinto Bandeira, Vale dos Vinhedos and Nova Pádua showed differences in the temperature, rainfall and humidity conditions used for the production under microvinification conditions of Merlot and Cabernet Sauvignon varieties, in the harvests of 2005 and 2006. An isotope ratio mass spectrometer coupled to an elemental analyzer was used to measure the 13C/12C of ethanol and the 18O/16O of wine water. Regardless of the grape variety used, it was possible to determine the subregion through measurement of the ,18O values in both harvests. The altitudes of the different subregions led to statistical differences and demonstrated an influence mainly on the ,18O values of wine water. The ,18O value of wine water was determined to be more selective for the determination of the cultivation subregions than the ,13C value of the ethanol. The altitude and latitude influenced mainly the , 18O values of wine water and the ethanol. The climatic influences are more noteworthy in distinguishing the year of the harvest than the cultivation subregion. Copyright © 2010 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||||||||