National Geographic : 1950 Feb
Picks and Shovels Bite into Panama Earth to Uncover Relics of Indians Who Vanished Five Centuries Ago Workmen start a trench near Barriles, launching archeology's first study of a culture earlier than those of near-by regions. Looters had combed the site for valuables. Six inches down, diggers found a layer of volcanic ash from a pre-Columbian eruption. Tombs six feet deep yielded large carved metates (corn-grinding stones).