Trace and Minor Element Analysis of Obsidian from the San Francisco Volcanic Field Using X-Ray Fluorescence

Sources of Archaeological Obsidian in the Southwest: An Archaeological, Petrological, and Geochemical Study

“…Apparently, the San Francisco volcanic field is quite complex, not unlike the Medicine Lake Highland field in northern California (Hughes 1982). Sanders et al (1982) arrived at similar conclusions in their more recent quantitative analysis of San Francisco field obsidians.…”

“…The obsidian sources within this field are, perhaps, the best studied in the Southwest (Jack 1971;Robinson 1913;Sanders et al 1982;Schreiber and Breed 1971). Although the chemical variability within sources in this field generally is less than in the mid-Tertiary sources to the south, the magmatic relations between some of these sources as previously reported probably are in error (Jack 1971;Sanders et al 1982). See Schreiber and Breed (1971: Figure 1) for a map of the field.…”

“…The nodules frequently were reduced at the source and flakes occur throughout the source area, but no intensive reduction areas were located. Published sources include Jack (1971), Moore et al (1960), Robinson (1913), Sanders et al (1982), Schreiber and Breed (1971). RS Hill.…”

“…With the advent of more efficient computer supported energy dispersive X-ray spectrometers, it now is possible to detect a number of elements simultaneously in the time it takes to analyze a few elements on the older manualwavelength instruments (Goffer 1980;Jenkins 1974;Macdonald 1980). With this spate of data, archaeologists turned to multivariate statistical techniques to determine assignments of archaeological information to source data (see Newman and Nielsen 1985;Sanders et al 1982). The problems here are complicated by both overlapping source data as above, and also by the problems of the many statistical and data assumptions inherent in multivariate techniques (Johnson and Wichern 1982).…”

Mass Production and Procurement at Valle del Azufre: A Unique Archaeological Obsidian Source in Baja California Sur

“…Archaeological obsidian research in the United States Southwest, until recently, has lagged significantly behind other regions (Shackley 1988(Shackley , 1995b. Not until the 1980s had significant petrological and geochemical research been available (Baugh and Nelson 1987; Hughes 1986, 1988Newman and Nielsen 1985Sanders et al 1982Shackley 1988, 1991, 1992, 1995bStevenson and Klimkiewicz 1990; see Shackley 1990 for a discussion of the history of research). Whereas a number of what seem to be minor sources of glass are appearing in archaeological contexts, most of the sources are known and characterized in the United States portion • of the Southwest (Shackley 1995b).…”