Subterranean transport and deposition of quartz by ants in sandy sites relevant to age overestimation in optical luminescence dating

An artificial layered sandy site was created using a combination of native sand and colored sand (3 parts native uncolored quartz, 1 part colored quartz) in Apalachicola National Forest near Tallahassee, Florida. Twelve layers of sand, each 1 by 1 m in horizontal extent by 10 cm in thickness were emplaced to a depth of 2 m followed by implantation at the surface of a Florida harvester ant (Pogonomymrex badius) colony (the lower two layers were 50 cm thick). The colony excavated a nest, and after 7 months, the sand layers were excavated to the base to test the hypothesis that sand grains were moved upward within the ant nest without reaching the surface. The ants penetrated 11 of the 12 colored layers reaching a depth of 130 cm. Thirty nine sticky-acetate peels of ant chamber floors were collected and colored sand grains were counted under a microscope. More than 16,000 grains were identified in layers that did not originally host them. Of these, more than 80% were unambiguously moved upward. This means that possibly as many as 54,000 upwardly mobile grains were present (ratio of 3:1 uncolored to colored). In relation to optical luminescence (OSL) dating, this means that grains that would not have been optically zeroed by transport to the surface (defined here as subterranean-transported) were present in abundance, and that if the site was ancient, there would have been found many grains that were older than the layers they presently reside in, even if only one colony of harvester ants had disturbed the layers. This is in addition to the fact that backfilling of chambers and tunnels may contribute even more significantly to the presence of a subterranean-transported component of an OSL sample. We conclude that ants can significantly affect the age distributions in sandy archaeological sites. Multiple examples of such disturbances have been documented in the literature. Most relevant to our results are recent studies of the OSL chronology of Pre-Clovis-age and Palaeoindian age archaeological sites in sandy environments in North America that may have been compromised by ant bioturbation of quartz sand grains. Here we have examined in detail the potential effects of one episode of ant nest-building on the age overestimation of affected sediments. From this we found that as few as 12 episodes of bioturbation involving backfilling of chambers in the same volume of sand could lead to the presence of 1 contaminant grain per 50 grains of sample.     

New specimens of the logrunner Orthonyx kaldowinyeri (Passeriformes: Orthonychidae) from the Oligo-Miocene of Australia

Nguyen, J.M.T., Boles, W.E., Worthy, T.H., Hand, S.J. & Archer, M., 2014. New specimens of the logrunner Orthonyx kaldowinyeri (Passeriformes: Orthonychidae) from the Oligo-Miocene of Australia. Alcheringa 38, 000–000. ISSN 0311–5518.

Logrunners (Orthonychidae) are a family of ground-dwelling passerines that are endemic to the Australo-Papuan region. These peculiar birds are part of an ancient Australo-Papuan radiation that diverged basally in the oscine tree. Here we describe eight fossil tarsometatarsi of the logrunner Orthonyx kaldowinyeri, and a distal tibiotarsus tentatively assigned to this species from sites in the Riversleigh World Heritage Area, Australia. The new fossil material ranges in age from late Oligocene to early late Miocene, and extends the temporal range of the Orthonychidae into the late Oligocene; this is the geologically oldest record of the family. These specimens also include the oldest Cenozoic passerine fossils from Australia that can be confidently referred to an extant family. The distinctive features of the tarsometatarsus and tibiotarsus of extant logrunners, which are probably related to their unusual method of foraging, are also present in O. kaldowinyeri. Assuming that O. kaldowinyeri had vegetation requirements similar to those of extant logrunners, its presence in various Riversleigh sites provides clues about the palaeoenvironment of these sites.

Jacqueline M.T. Nguyen [jacqueline.nguyen@unsw.edu.au] (author for correspondence), Suzanne J. Hand [s.hand@unsw.edu.au], Michael Archer [m.archer@unsw.edu.au], School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, NSW 2052, Australia; Walter E. Boles [walter.boles@austmus.gov.au], Ornithology Section, Australian Museum, 6 College Street, Sydney, NSW 2010, Australia; Trevor H. Worthy [trevor.worthy@flinders.edu.au], School of Biological Sciences, Flinders University, Adelaide, SA 5001, Australia. Received 19.9.2013; revised 11.10.2013; accepted 25.10.2013

http://zoobank.org/urn:lsid:zoobank.org:pub:F4F6219A-22A3-4F6B-8AEE-2957A227C0E0     

Family stories,public silence: Irish identity construction amongst the second‐generation Irish in England

Formal narratives of history, especially that of colonial oppression, have been central to the construction of national identities in Ireland. But the Irish diasporic community in Britain has been cut off from the reproduction of these narratives, most notably by their absence from the curriculum of Catholic schools, as result of the unofficial ‘denationalisation’ pact agreed by the Church in the 19th century (Hickman, 1995). The reproduction of Irish identities is largely a private matter, carried out within the home through family accounts of local connections, often reinforced by extended visits to parent/s ‘home’ areas. Recapturing a public dimension has often become a personal quest in adulthood, ‘filling in the gaps’. This paper explores constructions of narratives of nation by a key diasporic population, those with one or two Irish‐born parents. It places particular emphasis on varying regional/national contexts within which such constructions take place, drawing on focus group discussions and interviews for the ESRC‐funded Irish 2 Project in five locations — London, Glasgow, Manchester, Coventry and Banbury.     

Introduction: Reconsidering Futurism

The financial crisis hit Italy harder than many other Eurozone countries. In part this was due to the fact that the crisis came upon a system that was weakened by years of sub-par economic growth. One of the several endogenous factors that explain the stagnation of the Italian economy is the weak corporate governance in the industrial sector and parts of the financial one. A framework that was designed to maintain stability in the ownership of companies and of certain types of banking institution ultimately led to an inefficient allocation of capital and to a lack of investment, which contributed to the loss of competitiveness of Italian firms in a fast globalizing marketplace.     

Designing families and solid citizens: the dialectic of modernity and the Matrimonial Causes Bill, 1959

Policy-makers in the 1940s and 50s were intent on designing families which would produce solid citizens to engage in nation building. Historians offamilism treat it as an expression of modernism: a unifying, oppressive discourse now to be countered by the destabilising project of postmodernism. But this is not the whole story, for it omits the dialectical essence of 'the modern', which promises both 'progress' through technical rationality and individual achievement/self fulfilment. The other side of the dialectic has been avoided by dismissing individualism as a process of interpellation closely tied to the interests of technocratic elites. Out of the discontinuities within modernism there emerged opportunities for agency, the chance for people to make their own lives. The public controversy over the Matrimonial Causes Bill, 1959-at the height of what we are encouraged to think of as the familist decade-is explored as one instance.     

The Broken Past: Fractals in Archaeology

Many archaeological patterns are fractal. Fractal analysis, therefore, has much to contribute to archaeology. This article offers an introduction to fractal analysis for archaeologists. We explain what fractals are, describe the essential methods of fractal analysis, and present archaeological examples. Some examples have been published previously, while others are presented here for the first time. We also explain the connection between fractal geometry and nonlinear dynamical systems. Fractals are the geometry of complex nonlinear systems. Therefore, fractal analysis is an indispensable method in our efforts to understand nonlinearities in past cultural dynamics.