A group of cinder cones and associated lava flows SW of the town of Zapala at the southern end of the Loncopue graben form the Laguna Blanca volcanic field. A morphologically pristine cinder cone on the northern shore of Laguna Blanca is a prominent feature of the Laguna Blanca National Park, noted for its aquatic bird fauna, including black-necked swans and flamingos. The youthful-looking basaltic to trachyandesitic cinder cones and small shield volcanoes are considered to be of Holocene age, although no radiometric ages are available.