RESUMO
Kulna Cave is the only site in Moravia, Czech Republic, from which large assemblages of both Magdalenian and Epimagdalenian archaeological materials have been excavated from relatively secure stratified deposits. The site therefore offers the unrivalled opportunity to explore the relationship between these two archaeological phases. In this study, we undertake radiocarbon, stable isotope (carbon, nitrogen and sulphur), and ZooMS analysis of the archaeological faunal assemblage to explore the chronological and environmental context of the Magdalenian and Epimagdalenian deposits. Our results show that the Magdalenian and Epimagdalenian deposits can be understood as discrete units from one another, dating to the Late Glacial between c. 15,630 cal. BP and 14,610 cal. BP, and c. 14,140 cal. BP and 12,680 cal. BP, respectively. Stable isotope results (δ13C, δ15N, δ34S) indicate that Magdalenian and Epimagdalenian activity at Kulna Cave occurred in very different environmental settings. Magdalenian occupation took place within a nutrient-poor landscape that was experiencing rapid changes to environmental moisture, potentially linked to permafrost thaw. In contrast, Epimagdalenian occupation occurred in a relatively stable, temperate environment composed of a mosaic of woodland and grassland habitats. The potential chronological gap between the two phases, and their associations with very different environmental conditions, calls into question whether the Epimagdalenian should be seen as a local, gradual development of the Magdalenian. It also raises the question of whether the gap in occupation at Kulna Cave could represent a change in settlement dynamics and/or behavioural adaptations to changing environmental conditions. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12520-020-01254-4.
RESUMO
Sulphur is an element found in surplus in anthropogenic areas and one of the minerals responsible for the development of acid rains. The analysis of stable S isotopes provides a powerful tool for studying various aspects of the biogeochemical circulation of sulphur. δ(34)S values and S concentrations were determined in a 90-day experiment with the native moss Pleurozium schreberi from rural, urban and industrial sites in Upper Silesia in southern Poland. At the same time P. schreberi from a control site was transplanted to the same rural, urban and industrial sites and the δ(34)S values and S concentrations were determined in the same 90-day experiment. (34)S enrichment (up to 4.7) in the mosses tested indicates that these plants responded to environmental pollution stress. Sulphur isotopic composition in the transplanted P. schreberi was related to S concentrations in this species after 90 days of the experiment. Higher δ(34)S values and S concentrations were noted in native mosses than in those transplanted from rural and urban sites while an opposite situation was reported in industrial sites. The transplanted P. schreberi was a better sulphur bioindicator than the native moss in more polluted industrial sites and worse in less polluted rural and urban sites.
Assuntos
Poluentes Atmosféricos/análise , Bryopsida/química , Bryopsida/metabolismo , Monitoramento Ambiental , Isótopos de Enxofre/análise , Enxofre/análise , Poluentes Atmosféricos/metabolismo , Bryopsida/crescimento & desenvolvimento , Polônia , Enxofre/metabolismoRESUMO
Os isótopos estáveis de O, H e S foram utilizados para investigar a origem das rochas magmáticas nos Terrenos Jauru e Pontes e Lacerda do SW do Craton Amazônico, estado de Mato Grosso, Brasil. No Terreno Jauru as rochas granitóides do Greenstone belt Alto Jauru e da Suíte Cachoeirinha apresentam valores de δ18O entre +9,0 e +6,3 que indicam derivação a partir de magmas juvenis. Na Suíte Intrusiva Rio Branco valores de δ18O para rochas básicas estão entre +5,4 e +5,8 e para rochas félsicas entre +8,7 e +9,0; rochas intermediárias apresentam valores entre +7,3 e +8,3. Os valores mais baixos de δ18O, obtidos nas rochas básicas, são compatíveis com derivação mantélica, porém as rochas félsicas apresentam valores de δ18O compatíveis com origem crustais. Análises de isótopos estáveis de H (rocha total) forneceram valores de δD entre - 83 e -92, diferente das assinaturas de rochas metamórficas e de águas meteóricas. Resultados em sulfetos para isótopos estáveis de S em rochas básicas e intermediárias desta suíte apresentam valores de δ34S coerentes com uma fonte mantélica (entre + 0,7 e +3,8), enquanto os valores de δ34S (entre +5,2 e +6,1) obtidos nas rochas félsicas sugerem participação crustal na sua gênese. Na Suíte Santa Helena (Terreno Pontes e Lacerda) os resultados obtidos para δ18O se agrupam entre +4,4 e +8,9 indicando uma origem mantélica. O presente estudo confirma a importância da aplicação de isótopos estáveis para a compreensão de processos magmáticos e evolução crustal.
Stable isotopes of O, H and S were used to investigate the origin of magmatic rocks of the Jauru and the Pontes e Lacerda Terrains, SW portion of the Amazonian craton, Mato Grosso state, Brazil. Granitic rocks of the Alto Jauru Greenstone belt and Cachoeirinha Suite, Jauru terrain, present δ18O values between +9.0 and +6.3, indicative of derivation from juvenile magmas. The Rio Branco Intrusive Suite basic and felsic rocks' δ18O values fall, respectively, within +5.4 to +5.8 and +8.7 to +9.0 ranges; the intermediate rocks present δ18O between +7.3 and +8.3. The lower values of δ18O, obtained from basic rocks, are compatible with a mantle source, however the felsic rocks present δ18O values indicative of crustal source. The stable isotopes of hydrogen yielded δD values between - 83 and - 92, different from the δD signatures of metamorphic rocks and rain water. Sulphur isotopes in sulfides from basic and intermediate rocks of the Rio Branco suite presented δ34S values coherent with a mantle source (between + 0.7 and +3.8), whereas δ34S values between + 5.2 and + 6.1, obtained from the felsic rocks, suggest crustal participation in their genesis. For the Santa Helena Suite (Pontes e Lacerda Terrain) the δ18O values fall between +4.4 and +8.9. The present study confirms the advantages of using stable isotopes to understand magmatic processes and crustal evolution.
Assuntos
Isótopos de Oxigênio , Ecossistema AmazônicoRESUMO
Isotopic studies of nitrogen and sulphur inputs to plant/soil systems commonly rely on limited published data for the 15N/14N and 34S/32S ratios of nitrate, ammonium and sulphate in rainfall. For systems with well-developed plant canopies, however, inputs of these ions from dry deposition or particulates may be more important than rainfall. The manner in which isotopic fractionation between ions and gases may lead to dry deposition and particulates having 15N/14N or 34S/32S ratios different from those of rainfall is considered. Data for rainfall and throughfall in coniferous plantations are then discussed, and suggest that: (1) in line with expectations, nitrate washed from the canopy has 15N/14N ratios higher than those in rainfall; (2) the 15N/14N ratios of ammonium washed from the canopy are variable, with high ratios being found for canopies of higher pH in conditions of elevated ambient ammonia gas concentrations; and (3) in accord with expectations and previous work, 34S/32S ratios of sulphate washed from the canopy are not substantially different from those in rainfall. The study suggests that if atmospheric inputs are relevant to isotopic studies of the sources of nitrogen for canopied systems, then confident interpretation will require analysis of these inputs.