Sarah J. Kelloway

Stemmed Tools, Social Interaction, and Voyaging in Early–Mid Holocene Papua New Guinea

ABSTRACT To assess the proposal that the widespread distribution of early–mid Holocene obsidian stemmed tools in Papua New Guinea signifies wide ranging social networks, studies of their morphology, technology, and geochemical composition were conducted. It is argued that strong similarities in technology and form of artifacts made from both Manus and New Britain obsidians and their characterization to only one sub-source in each region indicate significant social interaction between these two island groups. Away from the obsidian sources, stemmed tools made from local raw material as well as imported obsidian suggest knowledge and practices were also distributed through a series of overlapping social networks. Long-distance voyaging to confirm and enhance status might explain the far-flung distribution of some tools. The new data about stemmed tool production on Manus and the early use of the Umleang-Umrei sub-source highlight the importance of further research in that region.

Analysis of Coal Cores Using Micro-XRF Scanning Techniques

This chapter explores the application of micro-XRF scanning to the inorganic geochemical analysis of drill cores obtained from coal exploration programs. It describes the development and use of a calibration to obtain detailed quantitative profiles of major inorganic elements through cores of bituminous coal seams, and hence allow rapid evaluation of mineral matter variations at a much greater detail than traditional bulk sampling techniques. The calibration was applied to core segments from an Australian coal seam, to quantify micro-XRF data obtained at 200 µm intervals using an Itrax core scanner system. In combination with high resolution optical imaging and X-radiography, also obtained from the scanning process, this enabled a detailed understanding of the variations in inorganic element characteristics through each coal segment, which could then be related to the distribution of particular mineral matter components. Such an approach can be used to provide a better understanding of the factors responsible for variations in coal quality, including the distribution of elements within the seam having particular economic or environmental significance.

Chapter 11:Raman Spectroscopic Studies of Obsidian

Obsidian is a natural glass produced when volcanic lava rapidly cools through the glass transition temperature and freezes, not permitting sufficient time for crystal growth.1 The amorphous and isotropic nature of obsidian means that when force is applied it fractures in a highly predictable manner ...