A period of vigorous exploration of spatial models of exchange followed on the initial availability of chemical characterization methods in the 1960s. In addition to responding to new proveniencing methods, these developments also reflected a convergence between formal analytical models borrowed from quantitative geography (Haggett 1966;Harvey 1969) and the spatial models of processual archaeology in the early 1970s. As the potential and the limitations of the formal geographical approaches have became more evident, archaeologists have been able to take stock of the insights from that period (Bradley and Edmonds 1993: 5-11;Clark 2003: 32-42;Hodder 1982;Torrence 1986: 10-37, 115-138).

Exploration of a variety of promising measures and ratios for regional analysis is one of positive products of these regional distance decay studies. For obsidian distance decay, the ideal analytical situation would involve a variety of metric measures for each artifact, and the chemical type would be known for every artifact of sourcable material. While such detailed analyses have not been generally available, analysts have made do with other measures such as visual assessment of obsidian type (although it is unreliable in many regions) and relative measures of abundance. These measures of abundance include: (1) proportion of obsidian in total lithic assemblage by count or weight, (2) proportion of obsidian flakes to other artifact classes like ground stone or ceramics, and (3) density of obsidian by excavated volume of soil. A variety of additional inventive measures were explored during this period. Further details from consumption contexts, such as variability in material type by spatial and temporal provenience, are important for regional studies, although acquiring consistent and comparable measures from various archaeological projects can be difficult.

Technological innovations promise to lend greater support to both chemical characterization and geographical analyses in coming years. Developments in GIS and other spatial technologies have greatly facilitated the management and analysis of spatial data. An associated technological development is portable chemical characterization devices such as portable X-ray fluorescence (XRF) units. It is likely that, in the not-too-distant future, XRF analysis will become a routine part of lab analysis for many archaeological projects (Jeff Speakman, May 2006, pers. comm.), a development that will significantly expand the archaeological significance of quarry studies and geographical relationships between production and consumption locales.

In sum, the confluence of spatial technology with the widespread use of non-destructive chemical characterization methods in archaeology will likely result in the emergence of a rigorous proveniencing and spatial analysis sub-discipline in archaeology in coming years. The foundations of this sub-discipline were explored in the 1970s but with greater refinement in theoretical approaches to exchange and the organization of technology, as well as the issues of artifact variability, and the consumption contexts of exchange, one may expect significant contributions from regional analysis in coming years.