Stable Isotope Chemistry, AMS Radiocarbon Dation and Documentation of a Four Corners Site

University Of Utah, Salt Lake City UT

Investigators

Abstract

With National Science Foundation support Drs. Joan Brenner Coltrain and Joel C. Janetski will continue their research on the timing and origins of maize agriculture in the Four Corner region of the American Southwest. The transition to food production in the American Southwest has been a topic of great interest to scholars since the beginning of professional work in the region early in the twentieth century. Some researchers argue that maize agriculture was rapidly introduced by prehistoric farming groups, migrating north from southern New Mexico and Arizona. Others contend that hunter-gatherer groups indigenous to the Four Corners region gradually became more dependent on maize over several millennia. Basketmaker sites contain the earliest evidence for farming dependency in the Four Corners region and date to as early as the mid-first century BC. The majority of these sites were excavated early in the twentieth century and yielded a distinctive material culture characterized by sandals of yucca, cedar bark and cordage, fur cloth, finely coiled basketry, twined bags and the atlatl and dart, digging sticks, hide for clothing and assorted beads and pendants including marine shell. Maize cobs were present as well as a suite of wild foods including pinyon and acorn leading to the long-standing debate noted above regarding the origins and importance of maize in Basketmaker diets. In addition to a rich and well-crafted suite of cultural artifacts, Basketmaker sites have yielded numerous, well-preserved human skeletal remains. Bone chemistry techniques introduced over the past three decades allow archaeologists to quantify dietary reliance on maize among prehistoric farming groups. Funding provided by the National Science Foundation will support the purification and analysis of collagen, the bone protein that records this information, with 100 Basketmaker burials from the Grand Gulch region of southeastern Utah. Purified bone collagen will also be accelerator radiocarbon dated providing a reliable date on each individual in the study. Previous work with Basketmaker burials from the Durango, Colorado, and Marsh Pass, Arizona, regions of the Four Corners, also funded by the National Science Foundation, revealed that Basketmaker II people there were fully reliant on maize by 400 BC with no evidence for a gradual transition to dependence on the cultigen in either area. Current research will determine if a similar pattern is evident at Grand Gulch, thought to be one of the earliest and most important Basketmaker areas. The transition to reliance on food production is a critical juncture in human history. Throughout the world, this transition resulted in the rapid expansion of human populations and increased social complexity. In the American Southwest the fundamental question asked nearly 100 years ago still has not been answered with certainty. Gathering data regarding the timing and the degree of dependence on maize among Basketmaker people is now possible through utilization of the techniques discussed above. Broader impacts bear on the repatriation of Native American remains as mandated by NAGPRA. Competing claims exist to all southwestern human remains. Establishing the temporal context of sampled burials will assist the institutions that curate these remains in their equitable repatriation. Previous work with burials from the Peabody Museum Basketmaker collection mentioned above identified numerous individuals incorrectly catalogued, dating to the Pueblo II and III rather than Basketmaker periods. Correct assignment of temporal affiliation has the potential to strongly impact decisions regarding repatriation.