Hydrothermal dolomitization,mixing corrosion and deep burial porosity formation: numerical results from 1‐D reactive transport models

Major corrosion has been found at depth in carbonate hydrocarbon reservoirs from different geologic provinces. Fluid inclusion microthermometry and stable isotopic compositions of carbonate cements, predating major corrosion, constrain the interpretation of the evolution of parental fluids during progressive burial and prior to the major corrosion event. Post‐major corrosion mineral paragenesis includes pyrite (‐marcasite), anhydrite, kaolinite (dickite) and fluorite. Although the post‐corrosion mineral paragenesis represents minor volumes of rock, it may provide valuable insights into the post‐corrosion brine chemistry. Using reactive transport numerical models, the roles of cooling and/or mixing of brines on corrosion have been evaluated as controls for dolomitization, deep burial corrosion and precipitation of the post‐corrosion mineral paragenesis. Modelling results show that cooling of deep‐seated fluids moving upward along a fracture may cause minor calcite dissolution and porosity generation. Significant dolomitization along a fracture zone and nearby host‐rock only occurs when deep‐seated fluids have high salinities (4 mol Cl kg^?1 of solution) and Darcian flow rates are relatively high (1 m³ m^?2 year^?1). Only minor volumes of quartz and fluorite precipitate in the newly formed porosity. Moreover, modelling results cannot reproduce the authigenic precipitation of kaolinite (dickite at high temperatures) by cooling. As an alternative to cooling as a cause of corrosion, mixing between two brines of different compositions and salinities is represented by two main cases. One case consists of the flow up along a fracture of deep‐seated fluids with higher salinities than the fluid in the wall rock. Dolomite does not precipitate at a fracture zone. Nevertheless, minor volumes of dolomite are formed away from the fracture. The post‐corrosion mineral paragenesis can be partly reproduced, and the results are comparable to those obtained from cooling calculations. Minor volumes of quartz and fluorite are formed, and kaolinite‐dickite does not precipitate. The major outputs of this scenario are calcite dissolution and slight net increase in porosity. A second case corresponds to the mixing of low salinity deep‐seated fluids, flowing up along fractures, with high salinity brines within the wall rock. Calculations predict major dissolution of calcite and precipitation of dolomite. The post‐corrosion mineral paragenesis can be reproduced. High volumes of quartz, fluorite and kaolinite‐dickite precipitate and may even completely occlude newly formed porosity.     

Seeking labour's aristocracy? The ‘Westphalian incident’ and Polish nationality policy in the immediate aftermath of war*

ABSTRACT. In the immediate aftermath of World War II the Polish state placed a high value on national homogeneity. The Polish Committee of National Liberation signed population exchange agreements with its socialist neighbours in September 1944 and expelled the German population who remained within the new Polish borders. Far less frequently discussed are the Polish state's efforts to persuade ‘Poles’ in Western Europe to move to Poland. This paper analyses how Polish policy towards ‘Westphalian Poles’ and the British reaction to Polish claims offer insight into both Polish and British nationality and citizenship policy in the immediate post‐war period. I argue that the quality of potential labour played an important role in both British and Polish thinking. The paper also contends that the ‘Westphalian incident’ gives useful insights into the emergence of the Cold War.     

A Nation‐state without the nation? The trajectories of nation‐formation in Montenegro1

ABSTRACT. Following the successful referendum of May 2006, Montenegro became the last of the former Yugoslav republics to opt for an independent state. Only fifteen years earlier, when the Socialist Federal Republic of Yugoslavia collapsed, Montenegro was resolute to continue the Yugoslav state‐formation in a union with Serbia. This paper attempts to answer the following questions: Why did it take so much longer for the Montenegrin population to follow the experience of other republics in its decision on independence? How can one explain a staggering change in public opinion on questions of national self‐determination over such a short time‐span? And, finally, what are the dominant discourses of “Montenegrin‐ness”? The authors argue that the answers to these questions are to be found in the particularities of Montenegro's historical development, and especially in the structural legacies of state socialism. The consequence of these developments was the formation of two separate Montenegrin national ideologies: one which sees Montenegrins as ethnically Serb, and the other that defines Montenegrins in civic terms. The paper concludes that these two divergent trajectories of nation‐formation in Montenegro are largely the unintended consequence of intensive state‐building, cultural and political modernisation and, most of all, the gradual politicisation and institutionalisation of high culture.     

Hybrid finite element–finite volume discretization of complex geologic structures and a new simulation workflow demonstrated on fractured rocks

The generation of computational meshes of complex geological objects is a challenge: their shape needs to be retained, resolution has to adapt to local detail, and variations of material properties in the objects have to be represented. Also mesh refinement and adaptation must be sufficient to resolve variations in the computed variable(s). Here, we present an unstructured hybrid finite element, node‐centred finite‐volume discretization suitable for solving fluid flow, reactive transport, and mechanical partial differential equations on a complex geometry with inhomogeneous material domains. We show that resulting meshes accurately capture free‐form material interfaces as defined by non‐uniform rational B‐spline curves and surfaces. The mesh discretization error is analysed for the elliptic pressure equation and an error metric is introduced to guide mesh refinement. Finite elements and finite volumes are represented in parametric space and integrations are conducted numerically. Subsequently, integral properties are mapped to physical space using Jacobian transformations. This method even retains its validity when the mesh is deformed. The resulting generic formulation is demonstrated for a transport calculation performed on a complex discrete fracture model.     

Evidence of Stress Fracture in a Homo antecessor Metatarsal from Gran Dolina Site (Atapuerca,Spain)

We present the palaeopathological analysis of a right fourth metatarsal (ATD6‐124) recovered from the Atapuerca–Gran Dolina site (Spain). This fossil, ca. 1 Ma, belongs to Homo antecessor, the earliest known European hominin species. The metatarsal exhibits a proliferative lesion on its medial periosteal surface. Periosteal reaction can be the bone response to a wide number of injurious processes. We describe a lesion on the basis of macroscopic and microscopic analyses, including microtomography and scanning electron microscopy. Externally, the osteoblastic lesion presents a highly porotic and disorganised morphology. Internally, we observe a series of micro‐fractures on the compact bone that do not affect the medullary canal. We provide a differential diagnosis and suggest that the ATD6‐124 lesion could correspond to a pedal stress fracture, also known as fatigue or march fracture. Stress fractures have been related to a load increase and muscular fatigue. This type of fracture has been widely reported in the foot of soldiers and athletes, which are usually engaged in strenuous, excessive or prolonged locomotive activities. Despite its high frequency in these groups, stress fractures have not been reported as such in fossil collections, with the exception of a metatarsal belonging to the Sima de los Huesos site (Atapuerca). Copyright © 2013 John Wiley & Sons, Ltd.     

Documenting Archaeological Mortuary Features using High Dynamic Range (HDR) Imaging

This technical note presents a refined technique for photo‐documenting archaeological mortuary features using High Dynamic Range (HDR) imaging. Mortuary features in archaeological context can be complex and delicate given the wide variability in grave constructions and preservation of human skeletal remains. It is therefore critical to obtain the greatest detail possible when photo‐documenting these features. HDR techniques represent more contrast in photographs and provide greater detail across the DR of illumination within mortuary features—where complex arrangements of human remains can obscure or darken other elements or associated funerary objects, making them difficult to identify in traditional photographs. HDR can be employed with most standard digital single lens reflex cameras used for archaeological field projects, is easy to learn and employ (as described here), can be processed and produced with commonly used photo editing programs, and is ideal for use in unpredictable conditions that are often encountered with archaeological mortuary features and in field conditions. Copyright © 2013 John Wiley & Sons, Ltd.     

Australian geography: The next 10 years (and beyond)?

Geography: Shaping Australia's Future (2018) provides a ‘strategic plan’ for geography aligned with the national research priorities, as well other key areas where Australian geographers are addressing environmental and societal challenges. To provide context, we first describe the state of geography in Australian universities. We then articulate ways forward for strengthening Australian geography—both within the discipline and how we interact externally. We describe how geography may better contribute to policy agendas, capitalising on our unique perspectives of space, place and the environment, but also highlight how we might improve these contributions through a more unified approach across human and physical geography. Third, we discuss opportunities for geographers to build the reputation of the discipline and ways to advocate for its importance in the wider academy, school curricula and community. We conclude with some preliminary suggestions on how Australian geographers may better engage and contribute to the United Nations Agenda 2030 Sustainable Development Goals.     

Electron Microprobe Analysis of 9th–12th Century Islamic Glass from Córdoba,Spain

Twenty‐six samples from domestic assemblages of 9th–12th century Córdoba were subjected to electron microprobe analysis. The results reveal two main compositional types. The first, encountered in 13 of the samples, seems to result from the combination of plant ashes with high‐impurity sand, and has some contemporary parallels from Syria and Egypt. The second type is a lead–soda–silica glass, encountered in a relatively high proportion of the glasses (11 of the 26 sampled), possibly formed by the addition of lead metal to existing glasses and with very few known parallels. These are among a very small number of results available to date on the chemical composition of glasses from medieval Spain, and the presence of a high proportion of lead–soda–silica glasses is particularly interesting, possibly indicating a technological practice unique to, or originating in, the western Muslim world.     

Reframing Bi‐nationalism in Palestine‐Israel as a Process of Settler Decolonisation

This paper examines some of the emerging critical civil society debates in relation to the one‐state solution being the most appropriate geo‐political arrangement for the articulation of freedom, justice and equality in Palestine‐Israel. This is done with reference to the Israeli Committee Against House Demolitions’ 2012 statement in support of a bi‐national state and the ensuing critiques it attracted from Palestinian supporters of the one‐state position. Drawing on these debates which have largely revolved around Jewish Israeli rights to political self‐determination in Palestine‐Israel, this paper proposes that alternative versions of self‐determination as cultural rights for the established Hebrew‐speaking national community represent a more inclusive form of self‐determination in the eventuality of decolonisation.