Brief Overview of Geochemical Research Laboratory

Established in 1986 by Dr. Richard Hughes, Geochemical Research Laboratory (GRL) was the first independent laboratory in the United States to specialize exclusively on non-destructive quantitative energy dispersive x-ray fluorescence (edxrf) analyses of obsidian artifacts and archaeologically-significant geologic obsidians. From 1986 through 1994, the laboratory was located in Rancho Cordova, California, and in early 1995 the lab moved to a larger facility in Portola Valley, California. Instrumental analyses from 1986 through mid-2003 were done on a Spectrace 5000 (Tracor X-ray) edxrf spectrometer, while those conducted from mid-2003 to the present have employed a QuanX EC edxrf spectrometer (see Laboratory equipment).

With more than 30 years of experience in the field of archaeological geochemistry, Dr. Hughes has conducted edxrf (obsidian sourcing) research on tens of thousands of samples for educational institutions, governmental agencies, museums, and private consulting firms. The results have been disseminated in numerous formal academic publications (in e.g., American Antiquity, Anthropological Papers of the American Museum of Natural History, Archaeologia Islandica, British Archaeological Reports (International Series), California Archaeology, Canadian Journal of Archaeology, Geoarchaeology, Geological Society of America Special Papers, Journal of Archaeological Science, Journal of California and Great Basin Anthropology, Journal of the Idaho Academy of Science, Latin American Antiquity, Northwest Science, Plains Anthropologist, Texas Journal of Science, University of California Archaeological Research Facility Contributions series, University of Oregon Anthropological Papers, University of Utah Anthropological Papers) ) and in more than 2,000 letter reports. Most of the lab's research has focused on the far western region of North America (Arizona, California, Colorado, Idaho, Montana, New Mexico, Nevada, Oregon, Utah, Washington, and Wyoming) although studies have been conducted, and are continuing, on obsidians found in archaeological contexts in the Great Plains and Midwest, Alaska, Baja California, Canada, Mesoamerica, South America, Tibet, and Iceland.

Dr. Hughes also has recently undertaken studies of flint from geological and archaeological contexts in Scandinavia (Denmark and Sweden), Lithuania, and Poland, with results published in Acta Archaeologica, Archaeometry, Fornvännen, Geologija, and Journal of Nordic Archaeological Science.

Laboratory equipment includes an edxrf spectrometer, dedicated microcomputers, a large number of international rock standards for calibration and quality control, and an extensive in-house geologic reference collection of volcanic rocks from throughout North America and Mesoamerica, which is augmented regularly though field collection expeditions.

All edxrf analyses at GRL are conducted personally by Dr. Hughes, who authors all letter reports issued from the lab.

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