Some 60 km southeast of Socorro, N.M., a low gravel ridge runs above the Chupadera Wash in the Rio Grande Rift Valley. The remote Mockingbird Gap is a dry, narrow strip half a mile long, but thousands of years ago it was a lush wetland – and a popular site for an early Clovis culture, judging by the wealth of projectile points found there.
Recently, anthropologist Marcus Hamilton, a postdoctoral fellow at SFI and the University of New Mexico, and colleagues examined 296 projectile points from two locations: Mockingbird Gap and a region in the central Rio Grande Rift collected by the late geologist Robert Weber over 60 years ago, the earliest and biggest collection of Clovis tools yet found.
The broad, bifacial spear points fit the manufacturing pattern the Clovis used 13,000 years ago. Geological analyses link all the points' obsidian, chert, and other high quality stone to a handful of rock outcrops, mostly nearby but some hundreds of kilometers away.
"The two assemblages are probably linked, as all the raw materials are coming from known outcrops in the northwest corner of New Mexico," Hamilton says. "It suggests strongly that the same people probably settled in this region for a while."
The clusters of artifacts suggest different camping events, possibly by groups coming together, briefly, over many years, to camp seasonally amid a verdant Pleistocene riverside.
Hamilton's research interests include understanding how human ecology evolved, particularly its shift from hunter-gatherer lifestyles to more settled agrarian societies.
The study of Clovis points "gives you a nice flavor of what human adaptation and human ecology looked like at the time, where Mockingbird Gap was a summer camp," he says.
One distant source of obsidian, Cow Canyon, is so small that residents "would have to know it, not stumble across it," he says.
A novel find was a set of miniature points, just a few millimeters long, that might have been children's toys or pieces flintknappers practiced on while learning point making techniques.
The rich findings in this poorly documented region indicate that early human arrivals to North America adapted to the landscape in part by learning a vast geographic region in great detail, the paper notes.
The paper was published in American Antiquity (April 2013)
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