THE POSSIBLE FRACTIONATION OF LEAD ISOTOPES IN ANCIENT METALLURGICAL PROCESSES

The possibility of lead isotope fractionation in ancient lead production is examined. Kinetic theory relating to isotopic fractionation in non-equilibrium evaporation is considered and the feasibility of the alteration of lead isotope abundance ratios in ore roasting and smelting is assessed. Previous experimental work is shown to have been inconclusive and conclusions are drawn on the need for further research to quantify the possible extent of fractionation in practice.     

Formalizing the Informal Sector: Barriers and Costs

This article uses material from a series of case studies conducted in Latin America to analyse various aspects of the formalization of the informal sector. In particular, it examines the legal and bureaucratic barriers confronting informal sector micro-enterprises which seek to become part of the formal, legal circuit, and assesses the costs in time and money which are involved in the formalization process. The process itself is seen as consisting of two elements — achieving legality and retaining that status over time — each of which involves certain bureaucratic and financial demands. While recognizing that the requirements for formalization can represent a burden in some cases, the main finding of the article is that the procedures and related costs vary between countries to such a degree that it is impossible to claim, as some earlier studies have done, that disproportionate regulation and bureaucracy constitute an insurmountable obstacle to the legalization of informal sector enterprises.     

Experimental Boat and Ship Archaeology: Principles and Methods

The need for experiments to study physical aspects of craft of the past is stated, as well as the necessity for them to have clear aims and to follow the established principles of scientific enquiry. These principles are discussed in this joint paper by ten maritime archaeologists and others, together with methods and some points of management critical to their application in this field.     

The Impact of Urbanisation on Water Quality in the Lane Cove River,Sydney New South Wales: a Comparison of Urban and Non-Urban Catchments

The Lane Cove River drains an established urbanised catchment and is impacted by urban runoff, point sources of pollution from sewer overflows and leachate from a refuse tip. The Sydney Water Board conducted a three year water quality monitoring programme assessing the impacts of pollution. The findings are presented and the impact of urbanisation evaluated by comparing water quality in urban and non-urban catchments. Water quality in a near-pristine control creek was consistently better than the urban catchment in all weather conditions. During wet weather, water quality in urban creeks deteriorated significantly, although the control creek generally remained in a near-pristine condition. Poor water quality in urbanised reaches of the catchment has degraded the aquatic ecosystem, encouraged and sustained weed infestation of the riparian environment and restricted recreational use of the river.