Oro Negro explores the material and human memory of Lota, the Chilean town whose identity is deeply bound to the coal mines known for more than a century as the black gold of Chile. The pictures were made in 1997, when the definitive closure of the mines was announced — at the same time as Héctor López Espinoza was running a photography workshop with the town's miners. Through those pictures and the handwritten notes taken during that period, the volume builds an archive of a world about to end.