Global Patterns in the Exploitation of Shellfish

ABSTRACT

Shellfish are a crucial resource for past and present subsistence-level societies around the world. Despite the diversity of environments in which shellfish are exploited, an examination of the global patterns of shellfish exploitation reveal surprisingly common patterns in the opportunities allowed and constraints imposed by relying on shellfish. These commonalities, linked to the fundamental features of shellfish and their exploitation, can illuminate diverse social and ecological factors likely to influence variability in their archaeological signatures. Here we review contributions to this special issue and explore common trends in shellfish use and its archaeological consequences.     

Effects of episodic fluid flow on hydrocarbon migration in the Newport‐Inglewood Fault Zone,Southern California

Fault permeability may vary through time due to tectonic deformations, transients in pore pressure and effective stress, and mineralization associated with water‐rock reactions. Time‐varying permeability will affect subsurface fluid migration rates and patterns of petroleum accumulation in densely faulted sedimentary basins such as those associated with the borderland basins of Southern California. This study explores the petroleum fluid dynamics of this migration. As a multiphase flow and petroleum migration case study on the role of faults, computational models for both episodic and continuous hydrocarbon migration are constructed to investigate large‐scale fluid flow and petroleum accumulation along a northern section of the Newport‐Inglewood fault zone in the Los Angeles basin, Southern California. The numerical code solves the governing equations for oil, water, and heat transport in heterogeneous and anisotropic geologic cross sections but neglects flow in the third dimension for practical applications. Our numerical results suggest that fault permeability and fluid pressure fluctuations are crucial factors for distributing hydrocarbon accumulations associated with fault zones, and they also play important roles in controlling the geologic timing for reservoir filling. Episodic flow appears to enhance hydrocarbon accumulation more strongly by enabling stepwise build‐up in oil saturation in adjacent sedimentary formations due to temporally high pore pressure and high permeability caused by periodic fault rupture. Under assumptions that fault permeability fluctuate within the range of 1–1000 millidarcys (10^?15–10^?12 m²) and fault pressures fluctuate within 10–80% of overpressure ratio, the estimated oil volume in the Inglewood oil field (approximately 450 million barrels oil equivalent) can be accumulated in about 24 000 years, assuming a seismically induced fluid flow event occurs every 2000 years. This episodic petroleum migration model could be more geologically important than a continuous‐flow model, when considering the observed patterns of hydrocarbons and seismically active tectonic setting of the Los Angeles basin.     

An Early Historic Assemblage Offshore of Godawaya,Sri Lanka: Evidence for Early Regional Seafaring in South Asia

Investigations in 2010 by an international team of maritime archaeologists yielded a concentration of artefacts identified here by the authors as the remains of a shipwreck off the southern coastal village of Godawaya, Sri Lanka. The major findings from this site include many quern stones, various types of ceramics, and glass ingots. The comparative study of the artefacts from the Godawaya site and terrestrial sites of Sri Lanka and India suggest that the ship might have originated from the southern part of the Indian subcontinent. Based on analysis of the artefacts and radiocarbon dating of wood fragments from the site, a broad date of 2nd BCE to 2nd centuries CE is assigned to the assemblage, placing it within the early historical period. Thus, this is the earliest known and as-yet investigated shipwreck in South Asia. The survey findings are discussed and the assemblage is contextualised within the present lack of evidence for early vessels and seafaring in the region.     

Building the nation in Timor-Leste and its implications for the country's democratic development

This article contributes to the discussion of the international democratisation of the so-called ‘post-conflict’ or ‘fragile’ countries by addressing one of the most important but least studied issues in the literature—the relationship between democracy and nation-building. It does so by analysing the major socio-political aspects of the democratic nation-state-building process in Timor-Leste in the post-1999 period. It argues that contemporary international democratisation policies and practices prioritise the ‘stateness’ problem, conceptualised by reference to a set of organisational, procedural and functional concerns. Little attention is, however, paid to the ‘nationness’ question. As the experience in Timor-Leste indicates, it is the national ideas that determine the structural and operational parameters of democratisation, which is, after all, a process of socio-political transformation by which political power and wealth are redistributed amongst a variety of competing societal interests.     

The relevance of vein texture in understanding the past hydraulic behaviour of a crystalline rock mass: reconstruction of the palaeohydrology of the Mecsekalja Zone,south Hungary

This study reconstructs the palaeohydrogeologic evolution of the shallow‐to‐moderate Mesozoic subsidence history for the Mecsekalja Zone (MZ), a narrow metamorphic belt in the eastern Mecsek Mountains, Hungary. Brittle deformation of the MZ produced a vein system with a cement history consisting of five sequential carbonate generations and one quartz phase. Vein textures suggest different fluid‐flow mechanisms for the parent fluids of subsequent cement generations. Combined microthermometric and stable‐isotope measurements permit reconstruction of the character of subsequent fluid generations with different flow types, as defined by vein textures, yielding new information regarding the hydraulic behaviour of a metamorphic crystalline complex. Textural observations and geochemical data suggest that fracture‐controlled flow pathways and externally derived fluids were typical of some flow events, while percolation through the rock matrix and the relationship to the Cretaceous volcanism and dyke emplacement were typical of others. The difference in the mode of calcite deposition from pervasive fluids (i.e. pervasive carbonatisation along grain boundaries versus deposition in antitaxial veins) between two calcite generations related to the volcanism inspired a stress‐dependent model of antitaxial vein growth. Textural and isotope variations in a vein generation produced by the same parent fluid indicate rock‐dependent hydraulic behaviour for different rock types, distinct action of the contemporaneous fracture systems and different extents of fluid–rock interaction. Cathodoluminescence microscopy and fluid‐inclusion microthermometry shed light on the possible role of hydraulic fracturing in the formation of massive calcite. The time of formation was estimated from the isotope composition of the oldest calcite generation and its presumptive relationship with the sedimentary sequences to the north, whereas microthermometry permitted conciliation of the reconstructed flow sequence with the Mesozoic subsidence history of the Mórágy Block (including the MZ).     

A Difficult Dialogue: Statements of Compatibility and the Victorian Charter of Human Rights and Responsibilities Act

As a ‘third-wave’ Bill of Rights, the Victorian Charter of Human Rights and Responsibilities Act is premised on the twin goals of creating a ‘culture of rights’ within the bureaucracy and the emergence of a rights-based dialogue between Cabinet and the Parliament of Victoria through statements of compatibility. The first objective has been advanced through a revised policy process within the bureaucracy, but a dialogic engagement between Parliament and the Cabinet has yet to emerge in a substantive way. A number of factors account for this modest parliamentary dialogue: first, the functioning of a statutory Bill of Rights in a moderately sized Parliament with a strong partisan orientation; second, the general reluctance of the Cabinet to alter legislation once introduced into Parliament despite compatibility disagreements identified by the Scrutiny of Acts and Regulations Committee; and finally, the approach by both the Cabinet and backbenchers to statements of compatibility that limit their ability to facilitate rights-based parliamentary scrutiny. This article explores the contemporary difficulties of a parliamentary dialogue emerging in Victoria that are, in large part, the result of an unintended tension between pre-introduction scrutiny by the bureaucracy on behalf of the Cabinet, and secondly, the weakness of post-introduction scrutiny facilitated by Scrutiny of Acts and Regulations Committee via statements of compatibility.     

ORTHOIMAGE‐BASED DOCUMENTATION OF ARCHAEOLOGICAL STRUCTURES: THE CASE OF A MEDIAEVAL WALL IN PONTEVEDRA,SPAIN

During the completion of the expansion works at the Museum of Pontevedra (Spain), a stretch of about 60 m of the medieval walled enclosure surrounding the historic city centre was discovered. Due to its value as a heritage element, the discovery of this archaeological structure required the implementation of preservation activities and exhaustive documentation so that future generations will be able to know and enjoy this piece of history. This paper presents digital models that reproduce the original structure of the wall using close‐range digital photogrammetry, as well as orthophotos, which thoroughly document the dimensional and textural characteristics of the archaeological site. In addition to analysing the accuracy and validity of photogrammetry in the conservation of archaeological heritage, a methodology of data capture, processing and photogrammetry representation is evaluated.