Possible isotopic fractionation of argon in source obsidians and archeological artifacts from Kulkuletti, Ethiopia

Despite uniform geochemistry ⁴⁰Ar/³⁹Ar ages of 0.6, 1.25, and 1.3 Ma on obsidians from a source flow (Worja) and from archeological artifacts at the sites of Kulkuletti (near Gademotta, Ethiopia) have been interpreted to suggest that they derive from different source flows of different ages. A further suggestion is that the magmatic source of the obsidian flows was chemically homogeneous between 1.3 Ma and 0.6 Ma. Chemical analysis of these obsidians indeed suggests that they derive from a single flow. Reexamination of the argon isotopic data reveals that argon isotopes may have been fractionated within the flow, so that the assumption of an atmospheric ⁴⁰Ar/³⁶Ar ratio of 295.5 is inappropriate to use for computing ages. Three groups of data are apparent, and internally all yield ages near 1.3 Ma if the intercept value for ⁴⁰Ar/³⁶Ar from an isotope correlation plot is used for computation instead of using the atmospheric ratio. The Soret thermal diffusion effect provides a possible mechanism of fractionation of argon within the obsidian flow that is of approximately the right magnitude to explain the observations by in-diffusion of already fractionated atmospheric argon.     

Migration,the Urban Periphery,and the Politics of Migrant Lives

This paper explores the politics of migration through a focus on labor migration regimes and the urban lives of migrants in the Seoul Metropolitan Region of South Korea. In particular, it draws attention to the ways in which migrant lives highlight the limits of the contemporary emphasis on control in migration management regimes. The paper contends that while migration management certainly reworks the socio‐legal status of migrants, the desire for control is often displaced in the everyday presence and practices of migrants as urban residents. In order to develop this argument I focus on the notion of the urban periphery as a spatio‐temporal configuration that manifests marginalization but is also potentially generative, innovative and destabilizing. The paper proceeds by exploring three dimensions of the periphery: (1) the mobile commons that emerges in everyday life; (2) the process of becoming undocumented and the subversion of control; and (3) the tactics of recognition that challenge the peripheral location of migrants. In each case the focus on the urban periphery draws attention to the importance of visibility and invisibility in migration, to the uneven spatio‐temporal configuration of migrant lives in the city, and to the ways in which migrant desires constitute a politics that exceeds what is normatively expected of them.     

The British Archaeological Association Honorary Secretary’s Report For 1939

Abstract

In the Lady chapel at the east end of the north aisle of the church at Pucklechurch (Gloucestershire) are two effigial monuments, which have received little scholarly attention. The monuments are attributed to William de Cheltenham (d. between 1371 and 1374) and his wife Eleanor, and were set up in his lifetime within the chantry chapel dedicated to St Mary which William received licence to establish at Pucklechurch in 1337. Little remains of the chapel except an exquisite altar frontal. During the 19th century the two effigies were transposed. Various aspects of the conception and design of the Pucklechurch monuments reflect developments in monumental sculpture in Herefordshire.