Sebuku (Borneo)
Encyclopedia
Sebuku is a 275 square kilometre island south-east of Borneo
and administratively part of South Kalimantan
, Indonesia
. Sebuku is home to a large coal
mine operated by Straits Asia Resources, which produces 3 million tonnes of coal every year.
. It is roughly 35 kilometres (21.7 mi) from north to south and 10 kilometres (6.2 mi) from east to west at its widest point, covering a total area of 275 square kilometre. Administratively, it is part of South Kalimantan
, Indonesia
. It is on the Kanibungan Fault.
Coal was first found on the island by the Dutch colonial government
in 1925. Large deposits of coal, dating from the Eocene
, have been found in Sebuku's south-west region; the main deposit forms a syncline
which trends from north to south. The strata
around the coal is mainly mudstone
and shale
.
Sebuku is home to roughly 4,900 people, with a total population density of 17.8 PD/sqkm. Prior to the opening of the coal mine, it had no infrastructure; now there are small roads, a port, and a small airfield.
Due to estimates of coal reserves measuring eleven million metric tonnes, infrastructure for a mine was built beginning in June 1997; mining began in December of the same year, despite concerns that the mining could sink the island. The mine is operated by Singapore
-based Straits Asia Resources, a subsidiary of Straits Resources. Mining is done using multiple open pits
.
As of 30 June 2008, the total remaining coal was estimated at 384 megatonnes, with a reserve base of 19 megatonnes. Production is estimated to be 3 megatonnes per annum.
Borneo
Borneo is the third largest island in the world and is located north of Java Island, Indonesia, at the geographic centre of Maritime Southeast Asia....
and administratively part of South Kalimantan
South Kalimantan
South Kalimantan/South Borneo is one of the thirty-three Provinces of Indonesia and one of four Indonesian provinces in the Indonesian part of Borneo. The provincial capital is Banjarmasin...
, Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
. Sebuku is home to a large coal
Coal
Coal is a combustible black or brownish-black sedimentary rock usually occurring in rock strata in layers or veins called coal beds or coal seams. The harder forms, such as anthracite coal, can be regarded as metamorphic rock because of later exposure to elevated temperature and pressure...
mine operated by Straits Asia Resources, which produces 3 million tonnes of coal every year.
Overview
Sebuku is located to the south-east of Borneo, approximately 5 kilometres (3.1 mi) from Laut IslandLaut Island
Laut is an island in the Kota Baru Regency in the Indonesian province of South Kalimantan. It has an area of 2,062 km2....
. It is roughly 35 kilometres (21.7 mi) from north to south and 10 kilometres (6.2 mi) from east to west at its widest point, covering a total area of 275 square kilometre. Administratively, it is part of South Kalimantan
South Kalimantan
South Kalimantan/South Borneo is one of the thirty-three Provinces of Indonesia and one of four Indonesian provinces in the Indonesian part of Borneo. The provincial capital is Banjarmasin...
, Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...
. It is on the Kanibungan Fault.
Coal was first found on the island by the Dutch colonial government
Dutch East Indies
The Dutch East Indies was a Dutch colony that became modern Indonesia following World War II. It was formed from the nationalised colonies of the Dutch East India Company, which came under the administration of the Netherlands government in 1800....
in 1925. Large deposits of coal, dating from the Eocene
Eocene
The Eocene Epoch, lasting from about 56 to 34 million years ago , is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Palaeocene Epoch to the beginning of the Oligocene Epoch. The start of the...
, have been found in Sebuku's south-west region; the main deposit forms a syncline
Syncline
In structural geology, a syncline is a fold, with younger layers closer to the center of the structure. A synclinorium is a large syncline with superimposed smaller folds. Synclines are typically a downward fold, termed a synformal syncline In structural geology, a syncline is a fold, with younger...
which trends from north to south. The strata
STRATA
Strata Marketing Inc. is a Chicago, Illinois-based software company involved in connecting media buyers and sellers. It is owned by Comcast. As of 2010, it processes about $50 billion worth of media buys annually.-History:...
around the coal is mainly mudstone
Mudstone
Mudstone is a fine grained sedimentary rock whose original constituents were clays or muds. Grain size is up to 0.0625 mm with individual grains too small to be distinguished without a microscope. With increased pressure over time the platey clay minerals may become aligned, with the...
and shale
Shale
Shale is a fine-grained, clastic sedimentary rock composed of mud that is a mix of flakes of clay minerals and tiny fragments of other minerals, especially quartz and calcite. The ratio of clay to other minerals is variable. Shale is characterized by breaks along thin laminae or parallel layering...
.
Sebuku is home to roughly 4,900 people, with a total population density of 17.8 PD/sqkm. Prior to the opening of the coal mine, it had no infrastructure; now there are small roads, a port, and a small airfield.
Mining
Although the Dutch originally discovered at least 25 coal deposits on Sebuku, after realizing that the island may not survive mining they cancelled their plans. Instead, they kept the island as a preserved park to serve as a buffer for Laut Island.Due to estimates of coal reserves measuring eleven million metric tonnes, infrastructure for a mine was built beginning in June 1997; mining began in December of the same year, despite concerns that the mining could sink the island. The mine is operated by Singapore
Singapore
Singapore , officially the Republic of Singapore, is a Southeast Asian city-state off the southern tip of the Malay Peninsula, north of the equator. An island country made up of 63 islands, it is separated from Malaysia by the Straits of Johor to its north and from Indonesia's Riau Islands by the...
-based Straits Asia Resources, a subsidiary of Straits Resources. Mining is done using multiple open pits
Open-pit mining
Open-pit mining or opencast mining refers to a method of extracting rock or minerals from the earth by their removal from an open pit or borrow....
.
As of 30 June 2008, the total remaining coal was estimated at 384 megatonnes, with a reserve base of 19 megatonnes. Production is estimated to be 3 megatonnes per annum.