Mule Creek Obsidian
Rob Jones, Preservation Fellow and University of Arizona Graduate Student
The Mule Creek Area
The Gila River originates in the uplands of southwestern New Mexico and runs through fertile valley bottoms and deep box canyons before emerging from the mountains near Safford, Arizona, and continuing past Phoenix. The rich mountain valleys of the Gila and its tributaries have for centuries played host to diverse farming communities that gathered to take advantage of the rich agricultural soils these valleys provide. Mule Creek is one of these tributaries, flowing north from the town of Mule Creek, New Mexico, through an upland valley before dropping into the San Francisco River, which joins the Gila near Clifton. On the western edge of the Mimbres Mogollon area, Mule Creek has a long history of human occupation, but is best known as the source of the archaeologically important Mule Creek obsidian. This excellent tool stone was circulated widely in prehistory. Together with a range of upland and riparian resources, the obsidian source drew ancestral Native American communities to Mule Creek. As part of Archaeology Southwest’s focus on the Upper Gila area in late prehistory, my fellowship work has concentrated on Mule Creek and its environs, with an emphasis on understanding the role of migrant communities in the circulation of obsidian.
Obsidian in the Upper Gila
Previous research in the San Pedro and Safford areas conducted by Archaeology Southwest suggests that the Mule Creek obsidian was widely circulated in late prehistory, from the late 13th century onward. Mule Creek obsidian occurs as glassy black nodules embedded in the local tuff, from the size of pea gravel up to the size of a golf ball or larger. This volcanic glass is relatively homogenous, making it an excellent quality tool stone, though the relatively small nodule size constrains its uses somewhat. Mule Creek obsidian was probably traded as unworked nodules—this still needs to be fully investigated—and has been found as far west as the Phoenix Basin, a distance of approximately 200 miles (Shackley 2005). Because it can be chemically sourced, obsidian provides archaeologists with important information about social connections across space. The strong association of Mule Creek obsidian with migrant communities in Southern Arizona suggests that obsidian circulated widely among migrants, and our preliminary research seems to indicate the presence of an early migrant community at Mule Creek. Many questions about the nature of the relationship between obsidian and migrants remain, however—were migrants somehow “controlling” Mule Creek obsidian? Did they bring with them specific technologies for working obsidian, or have to adapt to a new kind of tool resource? How widely was Mule Creek obsidian circulated, and what communities (if any) didn’t use it? And, most importantly, what does this tell us about the social networks of migrant groups attempting to maintain an identity in a time of tremendous social change? These are a few of the questions that my research with Archaeology Southwest hopes to shed light on over the next few years.
Reference Cited
Shackley, M. Steven
2005 Obsidian: Geology and Archaeology in the North American Southwest. University of Arizona Press, Tucson.
