InChile,coal mining is restricted to a few places located in its southern half. Energy originating from coal stands for 11,6% of Chile's electricity consumption.[1] Currently the country is not considered a major producer of coal.[2]
The three zones of mining are Zona Central Sur (36–38° S), Zona Sur[A] (39–42° S) and Zona Austral[B] (51–54° S) in southernmost Chile.[1][3] Most of the coal resources of Chile lie in Zona Austral at southernmost Chile.[4]
| District[3] | Sub-district[3] | Coal-bearing formations | Coal age[5][6] | Sedimentary basin | Coal grade[3][4] | Large-scale mining at present |
|---|---|---|---|---|---|---|
| Zona Central Sur | Sector Norte | Itata Basin | Sub-bituminous | No | ||
| Sector Sur | Curanilahue Formation,[4]Trihueco Formation | Eocene | Arauco Basin | Bituminous | No | |
| Zona Sur | Pupunahue Beds,Mulpún Beds,Cheuquemó Formation,Parga Formation | Eocene orOligo–Miocene | Pupunahue-Mulpún Neogene Carboniferous Basin,Osorno–Llanquihue Basin | Sub-bituminous | No, mining ceased in the early 2000s | |
| Zona Austral | Loreto Formation | Eocene-Oligocene | Magallanes Basin | Lignitic andSub-bituminous | No, mining inInvierno ceased in 2020[7][8] |
Usage of coal fromBío Bío Region as fuel dates back to at least 1557 when, according toDiego de Rosales, governorGarcía Hurtado de Mendoza stayed inQuiriquina 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 ofBiobío River would be a centre of coal industry.[9]
It was however not until the mid-19th century that large scale coal mining began in the region.[10][3] The initial trigger of coal mining was the arrival ofsteamships to the port ofTalcahuano. 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.[11] The mining district of Biobío Region can be divided in two sectors: one south and one north ofBiobío River.[3]
In the northern sector the mine ofLirquén, which provided coal to the cement plant of "Melón" was once the most important one. The northern sector containssub-bituminous coal.[3]
The coals of the southern sector, i.e. those ofArauco Basin, are chiefly ofbituminous nature.[3] IndustrialistMatías Cousiño begun mining operations inLota in 1852.[3] Coal mining transformed rapidly Lota, from being a sparsely populatedfrontier zone in the mid-19th century, into a large industrial hub that attracted immigrants from all over Chile well into the 20th century.[11] Lota's coal mines werenationalized bySalvador Allende due to civil unrest and heavySocialist support, butprivatized again underAugusto Pinochet.[12] Given a high density ofgeological faults that displace the coal beds and the thin nature of these (less than one metre) mining activity in Arauco Basin proved difficult tomechanize.[13] Traditionally the centre of coal mining in Chile, large-scale coal mining inArauco Basin ended in the 1990s.[14] Despite the decline of the coal industry communities in the zone continue to identify with it.[11]
The following mines were at times active in Sector Sur of Zona Centro Sur:El Chiflón del Diablo, El Chiflón Costa, Mina Consolidada, Mina Chiflones Fortuna, Mina Manto Grande, Mina Socavón Victoria, Pique Anita and others.[3]
The Zona Sur coal district spans the regions ofLos Ríos andLos Lagos, roughly from the area ofValdivia toChiloé Archipelago. The coals of the Zona Sur district aresub-bituminous.[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. The study of the coals is hampered by the fact that there are few coaloutcrops and attemptedcorrelation between different localities has not been satisfactory. Age estimations vary. A common view is that the coals of Zona Sur are ofOligo-Miocene age being thus younger than those ofArauco Basin further north. Yet findings offoraminifers appear to indicate for older ages, that isEocene.[5] The geological units containing economically significant amounts of coal are thePupunahue Beds, the very similarMulpún Beds,Cheuquemó Formation andParga Formation.[15][16][17]
Some of the better known coal mines of Los Ríos Region are: Arrau,Catamutún, Ciruelo, Máfil,Mulpún andPupunahue.[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 inLos Ríos Region at the time, halted after anunderground fire in 2001.[1]
During a period of the 20th century the electric grid of the city ofValdivia was powered by coal from the mines nearMáfil.[3] Starting in 2009Antofagasta Minerals andCarbon Energy developed together anunderground coal gasification project in the closed Mulpún mine, however the project was put on hold in 2013.[18][19][20]
Somewhat south, in Los Lagos Region, coal beds can be found in the geological formations ofCheuquemó andParga. The thin coal beds of this last formation were subject of small-scale mining operations around the turn of the 20th century.[15]
In Magallanes Region,Riesco Island is being investigated for new projects.[14] Coal was first discovered in Magallanes Region byPedro Sarmiento de Gamboa who visited theStraits of Magellan in 1584.[21]
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.[21][22]
| Coal types by grade (lowest to highest) |  | |
|---|---|---|
| Coal combustion | ||
| Coal mining |
| |
Notes: [1] Peat is considered a precursor to coal. [2] Graphite is only technically considered a coal type. | ||
