the latter production, reserves are more
limited. The coal bearing strata in the
region are contained within the Tertiary
age (Palaeocene) Los Cuervos
Formation, which is divided into three
members: the upper, middle and lower.
The lower member comprises
predominantly claystones and
siltstones with layers of sandstone and
occasional coal seams. The middle
member is the main productive
member and comprises a sequence of
claystones, siltstones, sandstones and
up to 60 coal seams. The upper member
comprises predominantly sandstones
intercalated with siltstones and
claystones. The Los Cuervos formation
is between 245 and 1600 m thick and is
unconformably overlain by the
Miocene to Pliocene Cuesta formation.
The deposits lie on the various limbs
of the faulted La Loma syncline, of
which the main axis lies in the La Loma
licence and trends northeast‑southwest.
A series of thrusts, the El Hatillo,
La Loma and El Tigre faults, displace the
coal bearing strata that appear on the
El Descanso licence as the northwestern
limb of the Descanso syncline.
Other departments
Production from the other departments
is much more limited, much of it
coming from low productivity, labour
intensive underground mines, with few
mines producing in excess of 10 000 tpy.
It should be noted, however, that some
departments have high‑CV
metallurgical or anthracitic coals that
may command premium prices and
offer opportunities for future
development under suitable geological,
mining and infrastructure conditions.
In order to plan to mitigate for
climatic events, such as El Nino, that
may impact on hydroelectric power
generation, Colombia is planning to
introduce a number of thermal electric
power generation plants. Many, such as
Termotasajero and Termopaipa, will
operate on locally sourced coal and
provide a new additional market.
It should be noted that there are
substantial potential resources of
high-quality thermal coals that may be
amenable to opencast mining in the
Catatumbo Basin of Norte de
Santander, an area that has been subject
to security issues. This situation may
improve if the government is successful
in negotiating a peace settlement with
the Revolutionary Armed Forces of
Colombia (FARC). (
Editor's note: for
more on the peace talks, see Barry Baxter’s
article “Feeling the pinch”, p. 14.
)
Coal quality
Colombia’s coal exports are low ash, low
sulfur thermal coal: the benchmark CV
from Puerto Bolivar is 11 300 Btu/lb. The
International Energy Agency in its ‘Key
World Energy Statistics’ for 2010 has
expressed the energy values in thermal
Table 2. Cerrejón resources and reserves (million t)
Resources
Reserves
Measured Indicated Inferred Total
Proved
Probable
Total
2924
989
695
4608
661
93
754
Physiography of the Cesar Rancheriá Basin.
Geology of the Cesar Rancheriá Basin.
December 2015
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World Coal
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19
