Isotopes reveal sources of ancient timbers
By Sid Perkins
Analysis of some of the architectural timbers in ancient dwellings of the American Southwest has shown from which distant forests the massive logs came. This information could shed new light on trade relationships of one of the most complex societies in pre-Columbian North America.
Between A.D. 900 and 1150, Chaco Canyon was a thriving cultural center for the Anasazi. During that period, residents in what would later become northwestern New Mexico used hand-hewn sandstone and more than 200,000 logs to construct a dozen large, multiroom dwellings. Now, these so-called great houses sit abandoned amid an arid, treeless landscape, says Nathan B. English, a geochemist at the University of Arizona in Tucson. Chaco Anasazi culture collapsed during a regional drought that lasted 50 years.