Laguna Potrok Aike is a maar

Maar

A maar is a broad, low-relief volcanic crater that is caused by a phreatomagmatic eruption, an explosion caused by groundwater coming into contact with hot lava or magma. A maar characteristically fills with water to form a relatively shallow crater lake. The name comes from the local Moselle...

 lake

Lake

A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

 in the Pali-Aike Volcanic Field

Pali-Aike Volcanic Field

Pali-Aike Volcanic Field is a Pleistocene-to-Holocene volcanic field in Patagonia on the Argentina–Chile border, located north of the Straits of Magellan about 150 km northeast of Punta Arenas, Chile. The volcanic field contains lake-filled maars, along with basaltic scoria cones and spatter...

 of southern Patagonia

Patagonia

Patagonia is a region located in Argentina and Chile, integrating the southernmost section of the Andes mountains to the southwest towards the Pacific ocean and from the east of the cordillera to the valleys it follows south through Colorado River towards Carmen de Patagones in the Atlantic Ocean...

, Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

. The Potrok Aike Maar Lake Sediment Archive Drilling Project (PASADO) is planning a number of ICDP drill holes for October-November 2008: http://www.pasado.uni-bremen.de/. The aim is to investigate the crater-filling sediments and the underlying volcaniclastic deposits.