“These dates are game changers,” Seymour said. And in another nearby site, a separate set was dated to around 1150.
It was when Seymour and her team began testing samples from the San Pedro valley, however, that they found themselves going back even deeper in time.Īt the ruins of a settlement known as Santa Cruz de Gaybanipitea, a collection of pottery sherds returned dates in the late 1200s. Some of these pieces, too, dated to the 1400s. These and other locations also turned up plainware that was made by the Sobaípuri but had been traded to other, mobile groups. “This site dated 150 to 200 years earlier than anyone was saying, so I was very surprised,” she said.Īt another nearby site, sherds of more Sobaípuri pottery were similarly dated to the 15th century. Using this suite of techniques and radiocarbon dating, Seymour said, the more samples she looked at, the more “unusual and unexpected” the results became.Īt one settlement near a tributary of the Santa Cruz known as Sonoita Creek, fragments of Sobaípuri pottery dated by luminescence, as well as carbon-14 dating of charcoal, yielded dates from the 1400s. Together these technologies can help date objects like cooking pits, identify when pottery was fired, and determine how long some sediments have been buried. One of them, called thermoluminescence, can pinpoint the last time a material was heated to a certain temperature another, optically stimulated luminescence, can isolate when particles like quartz or feldspar were last exposed to light. Some of the sites had been excavated before, in the 1950s and ’60s, revealing evidence of the Sobaípuri’s signature oblong building style and plainware pottery.īut using ethnographic accounts, historical records, and the dating technology available at the time, most experts estimated that the Sobaípuri lived in Arizona no earlier than the 1540s, around the time that the Spanish arrived.įor her research, however, Seymour turned to new methods. Their traces are found mostly along the San Pedro, Santa Cruz, and Gila rivers in southeastern Arizona, where the Sobaípuri irrigated crops and constructed settlements in rows of elongated houses.Īrtifacts found among the ruins of a Sobaipuri house at Sonoita Creek, Arizona, testify to the tribal group’s presence around the time of the Hohokam’s collapse, according to a new study.
In a paper recently published in the Old Pueblo Archaeology Bulletin, Seymour describes her investigations of sites inhabited by a people known as the Sobaípuri, a branch of the O’odham whose descendants are now part of the Tohono O’odham. (Learn about new insights into the decline of another ancient American civilization: “ Epic Fire Marked ‘Beginning of the End’ for Ancient Culture of Cahokia, New Digs Suggest“) “Until now we have not had enough information on the O’odham - historically, the Upper Pima - to address this question from an archaeological standpoint. “Some of the big questions scholars have been asking for a very long time are: What happened to the Hohokam? Is there a relationship between the Hohokam and the O’odham? In other words, did the Hohokam become the O’odham?” said Seymour, an archaeologist with the Jornada Research Institute in New Mexico, and a specialist in early O’odham and Apache cultures. This flies in the face of scientific convention, which has held that the region was essentially vacant between the fall of the Hohokam in the late 1300s and the arrival of the first Spanish missionaries in the mid-1500s. Years of research in southeastern Arizona, the heart of the Hohokam homeland, have turned up what Seymour calls “abundant evidence” that another tribal group - the O’odham, whose members still call Arizona home today - lived in the region perhaps as early as the 1100s. Deni Seymour says she has turned up an important clue: Despite what most scientists have believed for decades, the Hohokam were not alone.
HOHOKAM ARROWHEADS SERIES
While the cause - or, more likely, series of causes - remains poorly understood, Dr. But around this time, something triggered their precipitous decline. The caliche “Big House” at Casa Grande Ruins in Arizona was built near the zenith of the Hohokam culture in the 14th century.īy the late 1300s, the Hohokam were perhaps the most populous cultural group in the Southwest.