The magnetic sourcing of obsidian samples from Mediterranean and near Eastern sources

The magnetic properties of obsidians are examined for their potential in sourcing obsidian artifacts. The three simplest to determine magnetic parameters—initial intensity of magnetization, saturation magnetization and low field susceptibility—are found to be effective discriminants of many Mediterranean, Central European and near Eastern sources. Although the between-source precision is not as good as geochemical analyses of minor and rare-earth elements, the technique demonstrated the existence of new sources that were subsequently confirmed by minor element analyses. Unfortunately some key sources do not appear to be readily distinguishable on these three simple magnetic parameters alone, although more sophisticated magnetic analyses may prove diagnostic. Despite this, it would appear that effective discrimination can be made in many cases, occasionally with more precision than minor element analyses. This technique therefore offers, as a minimum, a preliminary sourcing tool for use in many areas of the world, thus reducing the number of expensive geochemical analyses. Furthermore, its very low cost, non-destructive nature and speed open the possibility of quantitative evaluation of trade routes based on obsidian distributions, particularly as versions of the equipment are now suitable for use in the field.     

Settlement history in the eastern Rub al-Khali: Preliminary Report of the Dubai Desert Survey (2006–2007)

Regional archaeological survey in desert areas of Dubai, U.A.E., has identified numerous archaeological sites in this rapidly changing landscape. Subsurface geophysical surveys have been undertaken in concert with surface collection and test excavation to document the extent and chronology of each site. Contrary to expectations that deserts were permanently abandoned following the end of the mid-Holocene pluvial phase around 4000 BC, two sites, Al-Ashoosh and Saruq al-Hadid, show evidence of substantial occupation during the late third and early first millennia respectively. These findings suggest that the Rub al-Khali supported human settlement much later than is generally thought, challenging traditional understandings of the region's cultural and environmental histories.     

A Sixteenth-Century Draft Plan of Lisbon’s Western Suburb

The National Library of Brazil has in its cartographic collection a little-known late sixteenth-century ichnographic plan of Lisbon, Portugal, showing the city’s western extramural suburb. In this article the unfinished draft plan is analysed for what it reveals of the mapmakers’ surveying methods. Comparison of the plan with other historical sources suggests that it was produced by Giovanni Vincenzo Casale and Alexandre Massai for military purposes between 1590 and 1597. This makes it the oldest ichnographic plan of Lisbon known to date, replacing the better known ichnographic plan of Lisbon signed by João Nunes Tinoco in 1650.