Shown are two obsidian (volcanic glass) flakes excavated by Kansas Historical Society archeologists at a Middle Ceramic period Pratt complex village in Pratt County. The flakes were analyzed using X-ray florescence, a chemical analysis that indicates the original source of the obsidian. The flakes were found to be from two different lava flows on the same mountain peak in the Jemez Mountains near Taos, New Mexico. This type of analysis helps archeologists learn about ancient trade patterns, suggesting either trade with people further south or travel by Pratt complex people to the Texas panhandle.