The 3,000 km2 Pleistocene-to-Holocene Pali-Aike volcanic field straddles the Chile-Argentina border north of the Straits of Magellan, about 150 km NE of the town of Punta Arenas. The southernmost of the Patagonian basaltic plateau lavas, Pali-Aike contains lake-filled maars and basaltic scoria and spatter cones with associated fresh-looking lava flows. The distribution of maars and cones indicates that eruptions occurred along regional fissures oriented E-W and NW-SE. The earliest eruptions produced maars and lava flows that are now exposed only in river valleys. A second stage formed now-eroded spatter cones and soil-covered lava flows. The youngest cones and lava flows are found in the SE part of the field. The most recent volcanic event produced scoria and spatter cones and fresh lava flows not covered by soil. Ejecta covers prehistorical artifacts (Skewes and Stern, 1979).