Pupunahue is a coal mine and hamlet in Los Ríos Region near the towns of Máfil and Los Lagos. The coal beds exploited in Pupunahue belong to the Pupunahue Beds.[1] Geologically the sedimentary rocks of the Pupunahue Beds containing coal lie in Pupunahue Basin, a sub-basin of the larger Pupunahue-Mulpún Neogene Carboniferous Basin.[1][2] The coals of Pupunahue deposited during the Oligo-Miocene[A] in an environment with moderate marine influence and certainly less marine influence than for the nearby Catamutún coals.[2] In 2016 it was announced that the closed Pupunahue mine would become a national heritage site.[4]
^Fossil foraminifer studies have however cast doubts on the exact age of coals across southern Chile, being a possibility that many coals are of Eocene age and not of Oligo-Miocene age.[3]