Coal mining in Chile

Interior of the El Chiflón del Diablo coal mine at Lota.

Usage of coal from Bío Bío Region as fuel dates back to at least 1557 when, according to Diego de Rosales, governor García Hurtado de Mendoza stayed in Quiriquina Island.[3] Early British travelers had differing opinions on the economic value of Chilean coals, or more specifically, the coals of Zona Central Sur. While David Barry found the coals to be of good quality, Charles Darwin found them of little value. The British consul in Chile correctly predicted in 1825 that the area around the mouth of Biobío River would be a centre of coal industry.[6]

It was however not until the mid-19th century that large scale coal mining began in the region.[7][3] The initial trigger of coal mining was the arrival of steamships to the port of Talcahuano. These steam ships, most of whom were English, bought initially the coal very cheaply and the exploited coal seams were easy to work as they laid almost at ground level.[8] The mining district of Biobío Region can be divided in two sectors: one south and one north of Biobío River.[3]

The Zona Sur coal district spans the regions of Los Ríos and Los Lagos, roughly from the area of Valdivia to Chiloé Archipelago. The coals of the Zona Sur district are sub-bituminous coal.[3]

The geological context of the coals of Zona Sur is not fully understood as there are divergent views on the stratigraphy and the ages the coals. Hampering the study the coals is the fact that there are few coal outcrops and attempted correlation between different localities has not been fully satisfactory. Age estimations vary. A common view is that the coals of Zona Sur are of Oligo-Miocene age being thus younger than those of Arauco Basin further north. Yet findings of foraminifers appear to indicate for older ages, that is Eocene.[5] The geological units containing economically significant amounts of coal are the Pupunahue Beds, the very similar Mulpún Beds, Cheuquemó Formation and Parga Formation.[12][13][14]

Some of the better known coal mines of Los Ríos Region are: Arrau, Catamutún, Ciruelo, Máfil, Mulpún and Pupunahue.[3] While these mines had occasional spurts in activity only Catamutún was in continuous operation in the 1940s–2001 period.[3][1] Mining in Catamutún, the only active coal mine in Los Ríos Region at the time, halted after an underground fire in 2001.[1]

During a period of the 20th century the electric grid of the city of Valdivia was powered by coal from the mines near Máfil.[3] Starting in 2009 Antofagasta Minerals and Carbon Energy developed together an underground coal gasification project in the closed Mulpún mine, however the project was put on hold in 2013.[15][16][17]

Somewhat south, in Los Lagos Region, coal beds can be found in the geological formations of Cheuquemó and Parga. The thin coal beds of this last formation were subject of small-scale mining operations around the turn of the 20th century.[12]

In Magallanes Region, Riesco Island is being investigated for new projects.[11] Coal was first discovered in Magallanes Region by Pedro Sarmiento de Gamboa who visited the Straits of Magellan in 1584.[18]

The following mines have been exploited in Zona Austral over the years: Chilenita, Chinita, El Chino, Estela, Elena, Fernández Rocuant, Invierno, Josefina, Loreto, Magdalena, Natales, Peckett, Punta Arenas, Servidora, Soledad, Tres Hermanos, Tres Pasos, Tres Puentes, Vulcano.[18][19]