In situ decarboxylation of acetic and formic acids in aqueous inclusions as a possible way to produce excess CH4

Accurate reconstruction of diagenetic P‐T conditions in petroleum reservoirs from fluid inclusion data relies on valid measurements of methane concentration in aqueous inclusions. Techniques have been developed (Raman spectrometry) to provide sufficiently accurate data, assuming measured methane concentration has not been modified after aqueous inclusion entrapment. This study investigates the likelihood that organic acids derived from petroleum fluids and dissolved in formation water might suffer decarboxylation upon postentrapment heating within the fluid inclusion chamber, thereby generating excess CH₄ in the inclusions. Four different experiments were conducted in fused silica capillary capsules (FSCCs), mimicking fluid inclusions. The capsules were loaded with acetic (CH₃COOH) or formic (HCOOH) acid solution and were heated to 250°C for short durations (<72 h) in closed‐system conditions, with or without applying a fixed P_H2. Reaction products were characterized by Raman and FT‐IR spectrometry. Results indicate that decarboxylation reactions did take place, at variable degrees of progress, and that measurable excess CH₄ was produced in one experiment using acetic acid. This suggests that methane may be produced from dissolved organic acids in natural aqueous inclusions in specific situations, possibly inducing errors in the thermodynamic interpretation.     

Russia and Norway: Research Collaboration and Comparison of Asymmetrical Relations

Archaeological excavations in 1954, 1958, and 1962 directed by Dr. C.L. Vebaek of The Danish National Museum at the Norse site 0 17a in the modern Greenlandic town of Narssaq revealed a farmstead apparently occupied from the 11th century into the later phases of the Eastern Settlement. The excavations recovered a quantifiable amount of animal bone from well‐defined strata within and immediately around the main structure. These collections were analysed in 1976–77 by the authors and show both continuity and some important changes in subsistence patterns between occupational strata.     

‘That's not a good idea,mom': Negotiating children's subjectivity while constructing ‘home’ as a research site

Framing this methodological article are two main themes on which we elaborate: (1) constructing ‘home’ as a site for doing research with children, and (2) facilitating children's autonomy and subjectivity in the accessing and recruiting phases, thus providing them opportunities to buy into the research process. Drawing on joint experiences from two closely related research projects on a housing development in Norway, we bring to the fore and explore both the role of gatekeepers and sponsors and ongoing negotiations within the triangular parent–child–researcher relation.     

Fish,pots and grain: Early and Mid-Holocene adaptations in the Central Sudan

Cultural development in the middle Nile Valley from 10,000 to 2000 bp was characterized by significant subsistence changes — from hunting/gathering and simple aquatic resource exploitation to cultivation of domestic sorghum. Research in the Atbara and Khartoum regions enables us to identify distinct technological phases relating to resource diversification as well as specialization. Pottery was an important technological innovation which had far-reaching consequences for development of a more diversified use of aquatic and cereal resources. A basic distinction is made between cultivation and domestication as two separate but interdependent processes — the first a socio-economic process relating to peoples' activities, the second a biological process relating to morphological changes in the plants. Cultivation is considered to be evolutionarily prior and to have constituted the selection pressures which led to the emergence of domesticated plants. Cultivation of sorghum was practised from the 6th millennium bp but domesticated sorghum emerged only around 2000 bp. Specialized pastoralism and the use of secondary products like milk and blood appear to have become important in the late 6th millennium bp. An attempt is made to connect the development of technological traditions with that of Nilo-Saharan and Cushitic languages.

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Résumé Le developpement culturel dans la vallée du Nil moyen est caractérisé par un changement significatif du mode de subsistance: de chasseurs/cueilleurs exploitant de simple ressources aquatiques à celui de cultivateurs de sorgho domestiqué.Les recherches dans la région d'Atbara et de Khartoum ont permis de mettre en evidence des phases technologiques distinctes correspondant à la diversification et à la spécialisation des ressources. L'introduction de la poterie est une innovation technologique importante conduisant au développement de la diversification dans l'utilisation des ressources aquatiques et des céréales. La culture et la domestication sont considérées comme des processus distincts mais interdépendants — le premier étant un processus socio-économique lié aux activités humaines et le deuxième un processus biologique lié aux changements morphologiques des plantes.D'un point de vue evolutionniste, on considère que la culture s'est développée en premier, fournissant les pressions de selection qui conduisirent à l'émergence des plantes domestiquées. La culture du sorgho a été pratiquée à partir du sixième millénaire bp, cependant que le sorgho domestique n'émerge qu'aux environs de 2000 bp.Le pastoralisme specialisé et l'utilisation des produits secondaires tels que le lait et le sang semblent avoir pris de l'importance vers la fin du sixième millénaire bp.Un essai de corrélation du developpement des traditions technologiques avec ceux des langus de famille Nilo-saharienne et Couchitique est présenté.