Origins of formation waters in the Llanos foreland basin of Colombia: geochemical variation and fluid flow history

Wells located in the Colombian Andean foreland often produce biodegraded hydrocarbons and relatively fresh water (total dissolved solids concentrations of 2000 mg l^?1 dominate across most of the basin). The ratio of water to hydrocarbon in the produced fluids is high and has often been interpreted by explorationists and simulation engineers as being due to massive meteoric water invasion. To challenge this hypothesis, previously published and existing data are compiled here, along with 68 new water samples collected from both the surface (rivers) and subsurface (production wells), which are analyzed for major elements, salinity, and stable isotope compositions. The data indicate a mixed origin for the water, which involves formation water, meteoric water, and a third source that we interpret as being related to diagenetic processes (such as clay dehydration). Analyses of the variation of the parameters from north to south and west to east allow us to define the mixtures as coming from waters of different origins and make it possible to determine the relative contribution of each source.     

Creating the 1831 Canadian Census Database

The 1831 census database is the newest addition to the series of 19th century Canadian census microdata available for social science research, thanks to a collaboration between the Programme de recherche en démographie historique (PRDH) and FamilySearch. This article presents the work undertaken to prepare this database and the main challenges encountered in the course of this work. While the data extracted from the 1831 census are an invaluable tool for demographic research, particularly on account of the agricultural and industrial questions included in this census, cleaning these data have required particular attention to the age-sex-marital status tallies of the household co-residents. Additional efforts were devoted to integrating missing data for Montréal’s Notre-Dame parish and for other parishes.     

La république des « humeurs » : Les querelles dans le dictionnaire de Bayle

Quarrelling is a ‘routine’ activity of the Republic of Letters. This article demonstrates that quarrels played a key role in the field of historical criticism. The contention of this article is twofold. First, it explores the epistemological issues raised by Bayle while reporting the quarrels of the Republic of Letters, and demonstrates their creative potential, thus applying to historiography conclusions drawn by recent research on scientific controversies. It offers a new understanding of scholarly quarrels, here understood as a socially and intellectually structuring activity. Second, this article takes issue with the debate over Bayle’s historical pyrrhonism. As will be shown, the quarrels constitute a key element within a method of writing history that is both conscious of its limits and confident of its investigative powers     

Who Makes Weapons Procurement Decisions?

Despite the absence of scientific support for a tripartite alliance in defense policymaking, political scientists and the general public continue to subscribe to a sub government explanation. This article addresses the sub government dilemma as it applies to the area of weapons procurement. More precisely, it asks whether the sub government model accurately describes and adequately explains the decisions to develop and build major weapons systems. In answering this question, the critical assumptions or propositions that comprise the model are tested, relying upon published research and original data drawn from 19 cases of military hardware decisions. The findings do lend some qualified support for a military subgovernment.     

A Recent Doctoral Thesis

Advanced doctoral students whose dissertations are substantially concerned with the history of cartography are invited to contact the editor of this section (Dr Elizabeth Baigent, Wycliffe Hall, Oxford OX2 6PW, UK; elizabeth.baigent@wycliffe.ox.ac.uk) to discuss the submission of a short article. For a list of doctoral theses in progress see http://www.maphistory.info/futurephd.html.     

New insights into Byzantine glass technology from loose mosaic tesserae from Hierapolis (Turkey): PIXE/PIGE and EPMA analyses

This study focuses on the Byzantine glass tesserae from Hierapolis (Phrygia, central Turkey). Fifty-seven samples of loose tesserae from two sites in the town (the theatre and the church of St. Philip) are analysed by particule-induced X-ray emission and particule-induced gamma ray emission and electron probe X-ray microanalysis to obtain the chemical composition and identify the colourants and opacifiers. The aims are to add new information to the scant knowledge of the Byzantine glassmaking technology, to constrain the chronology of the mosaics and to trace the supply routes of the tesserae. In the destruction layers of the theatre, tesserae produced following the Roman glassmaking technology (natron glass opacified by calcium and lead antimonate) were found. They were made using a Levantine 1 raw glass, generally attributed to the early Byzantine period (fifth to sixth c.). In the church, the samples attest a technological change from Roman tradition, and a complex pattern according to building history (two phases are attested, probably in the sixth and eighth to ninth c.), and a multiplicity of supply. Three glass types and some recipes not attested before in this chronological range for the production of tesserae are documented, such as the use of a local low-chlorine natron glass for the production of black and red tesserae, the blue colouring by a source of cobalt with zinc in a natron glass tessera and the opacification with tin oxide (both in a lead-free and in a high-lead natron glass), as well as with quartz.     

The Seasonal Mobility of Prehistoric Gazelle Herds in the Azraq Basin,Jordan: Modelling Alternative Strategies Using Stable Isotopes

The hunting of Gazella subgutturosa was a dominant practice for Epipalaeolithic and early Neolithic hunter–gatherers in the east Jordan steppe. The seasonal mobility of this taxon in the Levant is poorly understood, especially for early prehistory when herd movements would have influenced hunter-gatherer use of the steppes. This paper proposes four patterns of seasonal herd mobility for G. subgutturosa centred on Jordan’s Azraq Basin. The four patterns are modelled using oxygen, carbon and strontium stable isotopes. Seasonal environmental signatures of each are understood through carbon and strontium isotopic variation in sixty modern plant specimens collected from twelve selected locations in north Jordan, published data on oxygen isotopes in local precipitation, and the adaptive behaviour of G. subgutturosa. The integrated isotopic datasets provide clear discriminatory markers for each proposed mobility pattern. Results will be applied in future to isotopic data from archaeological gazelle teeth from the Azraq Basin.