The application of failure mode diagrams for exploring the roles of fluid pressure and stress states in controlling styles of fracture-controlled permeability enhancement in faults and shear zones

Permeability enhancement associated with deformation processes in faults and shear zones plays a key role in facilitating fluid redistribution between fluid reservoirs in the crust. Especially in high fluid flux hydrothermal systems, fracture-controlled permeability can be relatively short-lived, unless it is repeatedly regenerated by ongoing deformation. Failure mode diagrams in pore fluid factor and differential stress space, here termed λ–σ failure mode diagrams, provide a powerful tool for analysing how fluid pressure and stress states drive failure, associated permeability enhancement and vein styles during deformation in faults and shear zones. During fault-valve behaviour in the seismogenic regime, relative rates of recovery of pore fluid factor, differential stress and fault cohesive strength between rupture events impact on styles of veining and associated, fracture-controlled permeability enhancement in faults and shear zones. Examples of vein-rich fault zones are used to illustrate how constraints can be placed, not just on fluid pressure and stress states at failure, but also on the fluid pressurization and loading paths associated with failure and transitory permeability enhancement in faults and shear zones. This provides insights about when, during the fault-valve cycle, various types of veins can form. The use of failure mode diagrams also provides insights about the relative roles of optimally oriented faults and misoriented faults as hydraulically conductive structures. The analysis highlights the dynamics of competition between fluid pressures and loading rates in driving failure and repeated permeability regeneration in fracture-controlled, hydrothermal systems.     

Liberalism and cultural claims in Central and Eastern Europe: toward a pluralist balance†

ABSTRACT. This article relies on cases from new EU member states in postcommunist Europe to integrate two overlapping debates about majority–minority relations. Since the Second World War, political theorists and international institutions have tended to discourage group‐rights approaches in favour of individual rights; meanwhile, policy‐makers who achieved interethnic peace in postcommunist Europe have often opted for group‐rights approaches. On the basis of political theory, international norms and the conduct of political elites in this region, we argue that both the individual‐rights and group‐rights approaches can be differentiated internally along the dimension of pluralism – that is, their willingness to accommodate multiple processes of cultural reproduction. Moreover, both group‐rights and individual‐rights approaches can offer justifications for restricting minority cultural opportunities; furthermore, restrictive group‐rights approaches sometimes cloak their efforts behind ‘Western‐sounding’ individual‐rights rhetoric. Likewise, both group‐rights and individual‐rights approaches can permit group accommodation that can lead to political integration. We find that de facto pluralist approaches to minority accommodation – often spearheaded by moderate parties of the majority in coalition with minority‐group parties – encourage ethnic peace, regardless of their foundation in individual or group rights.     

Theological Innovation from Spiritual Experience: Henry Alline's Anti‐Calvinism in Late Eighteenth‐Century Nova Scotia and New England*

The strident anti‐Calvinism of Nova Scotian revivalist Henry Alline (1748–1784), who left a substantial mark on the religious landscape of Nova Scotia and parts of New England, has been noted but largely neglected by historians. This article investigates Alline's anti‐Calvinism and concludes that it is best explained as arising from his own interpretation of his vivid spiritual experiences, particularly his dramatic conversion. Rather than simply rejecting Calvinist theology in favour of an emotive, experiential religion, however, Alline drew on his experiences to formulate an alternative anti‐Calvinist theology. Alongside other examples from the period, Alline's case suggests that evangelical “democratization” of popular religion in the eighteenth‐century transatlantic revivals could result in theological innovation rather than the abandonment of theology.     

‘Tangled up in Blue’: The Death,Dress and Identity of an Early Viking-Age Female Settler from Ketilsstaðir,Iceland

IN 1938, a woman’s burial was uncovered by road builders at Ketilsstaðir in north-eastern Iceland. Recently, her physical remains and associated funerary goods were re-examined by an international, interdisciplinary team and formed the basis for an exhibition at the National Museum of Iceland in 2015. This paper focuses on the items of dress that accompanied the woman — born in the British Isles, but who migrated to Iceland at a very young age — to gain insights into the ways her cultural identity was expressed at the time of her death. Here we explore the roles played by material culture in signaling her identity, and the technologies and trade networks through which she was connected, visually, to Scandinavia, the British Isles, and the Viking world at large.     

Empire by denial: the strange case of the United States

The issue of empire has once again become a major political question in American foreign policy discourse. But whereas in the 1960s the discussion was one that mainly concerned the radical left, over the past few years the debate has largely been conducted within neo-conservative circles. The discussion is one that should be taken seriously-in part because of its intrinsically interesting character and in part because of what it tells us about the Bush grand strategy. In the end, though, the issue of whether or not there is-or is not- an American empire, is perhaps of less importance than the fact that most Americans deny that such an empire exists. This has consequences both for the conduct of American foreign policy and for its successful execution.     

Fred Halliday,Marxism and the Cold War

Though possibly best known today as a specialist on the Middle East and Islam, it is often forgotten how central the Cold War was in defining Fred Halliday's understanding of world politics before 1989 and indeed even after. Building on the earlier work of Isaac Deutscher and E. H. Carr, Halliday developed a distinct theory of the Cold War which afforded him great insights but ultimately failed in explaining the complexities of the East–West relationship, and why it came to an abrupt conclusion in the late 1980s.     

Contemporary Sorted Patterned Ground in Low Altitude Areas of Tasmania

This paper summarises the distribution of patterned ground phenomena in Tasmania. It presents observations of low altitude sorted stone circles forming on glacial and alluvial deposits in the vicinity of Queenstown, Western Tasmania. Evidence suggests that freeze‐thaw derived patterned ground could develop in most inland valleys in Tasmania where cold air drainage causes sub‐zero ground temperatures in winter and permits the formation of ground and segregation ice to low elevations. Field observations suggest that patterned ground can only develop where freeze‐thaw processes are not inhibited by vegetation. The occurrence of patterned ground below altitudes of 900 m asl in Tasmania is largely a result of anthropogenic disturbance.