Today´s Mercurio (Section C, page 13) says that initial investigations by the “Servicio Nacional de Geologica y Mineria” find “sobretasa de extraccion” in the Alcaparrosa mine.
One of the local hills near me also has holes in the ground from mining, although nowhere near as big as this one. They are quite scary because they are deep enough to kill. Some of them lead down to another level, so the ground has two levels, i.e. if you fell down and survived somehow you could walk out elsewhere.