Last night's talk at the Arizona Geological Society meeting in Tucson by UA grad student Alyson Thibodeau
used isotopic geochemistry to trace the history of mining in the Southwest and propose a method that may allow geoarcheologists to finally pin down the route of Spanish explorer Vazquez de Coronado.
I didn't realize how little is known definitively about Coronado's epic trek in 1540-42. Or how passionate the debate is among those pursuing the answers.
Alyson is using lead and strontium isotopes to determine the sources of turquoise found across the Southwest and Mesoamerica. But it appears the same techniques work with lead musket balls and copper parts of crossbows used by Coronado's expeditions. Earlier attempts by other researchers to use major element geochemistry to trace the origin and provenance of the Coronado's lead and copper have not been as successful as initially hoped.