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100-566: The basin is of importance for hosting the worldwide tenth biggest and largest coal mine of Latin America, Cerrejón . The coals are mined from the Paleocene Cerrejón Formation , that also has provided several important paleontological finds , among others Titanoboa cerrejonensis , with an estimated length of 14 metres (46 ft) and a weight of 1,135 kilograms (2,502 lb), the biggest snake discovered to date,

200-871: A passive margin in the Paleozoic , followed by a compressive margin in the Late Permian to Triassic , a phase of rifting in the Jurassic . Subsequently, the basin experienced a back-arc basin setting in the Cretaceous , a second compressive margin during the Late Cretaceous to Eocene and a final intramontane phase since the Eocene. The passive margin phase was characterised by the deposition of shallow marine sediments in three periods, divided by unconformities . The unconformities have been dated to

300-705: A 70% increase over the 20 years since 1999. In 2018, the world production of brown coal (lignite) was 803.2 Mt, with Germany the world's largest producer at 166.3 Mt. China is most likely the second largest producer and consumer of lignite globally although specific lignite production data is not made available. Coal production has grown fastest in Asia, while Europe has declined. Since 2011, world coal production has been stable, with decreases in Europe and US offset by increases from China, Indonesia and Australia. The top coal mining nations are: Energy production from coal mining

400-724: A back-arc basin setting. The first phase of the Andean orogeny uplifted the Western Ranges and was characterised by magmatism in the Sierra de San Lucas in the northern Central Ranges , dated to the Albian to Cenomanian epochs. Sedimentation on the northern South American platform was of siliciclastic and carbonate character, the latter more dominant in the northern areas. In the Cesar-Ranchería Basin, this led to

500-467: A coal seam occurring near the top of a ridge or hill, the entire top is removed in a series of parallel cuts. Overburden is deposited in nearby valleys and hollows. This method usually leaves the ridge and hilltops as flattened plateaus. The process is highly controversial for the drastic changes in topography, the practice of creating head-of-hollow-fills , or filling in valleys with mining debris, and for covering streams and disrupting ecosystems. Spoil

600-405: A fourth of the world's energy. Coal extraction methods vary depending on whether the mine is an underground mine or a surface (also called an open cast) mine. Additionally, coal seam thickness and geology are factors in the selection of a mining method. The most economical method of coal extraction for surface mines is the electric shovel or drag line. The most economical form of underground mining

700-464: A fuel for extraction of iron from iron ore and for cement production. In the United Kingdom and South Africa , a coal mine and its structures are a colliery , a coal mine is called a "pit", and above-ground mining structures are referred to as a " pit head ". In Australia , "colliery" generally refers to an underground coal mine. Coal mining has had many developments in recent years, from

800-403: A greater proportion of the coal deposit than underground methods, as more of the coal seams in the strata may be exploited. This equipment can include the following: Draglines which operate by removing the overburden, power shovels, large trucks in which transport overburden and coal, bucket wheel excavators, and conveyors. In this mining method, explosives are first used in order to break through

900-440: A land use condition is not equal to the original use. Existing land uses (such as livestock grazing, crop and timber production) are temporarily eliminated in mining areas. High-value, intensive-land-use areas like urban and transportation systems are not usually affected by mining operations. If mineral values are sufficient, these improvements may be removed to an adjacent area. Strip mining eliminates existing vegetation, destroys

1000-440: A large dining-room table, but with hydraulic jacks for legs. After the large pillars of coal have been mined away, the mobile roof support's legs shorten and it is withdrawn to a safe area. The mine roof typically collapses once the mobile roof supports leave an area. There are six principal methods of underground mining: Coal is mined commercially in over 50 countries. 7,921 million metric tons (Mt) of coal were produced in 2019,

1100-447: A method that currently accounts for about 60 percent of world coal production. In deep mining, the room and pillar or bord and pillar method progresses along the seam, while pillars and timber are left standing to support the mine roof. Once room and pillar mines have been developed to a stopping point limited by geology, ventilation, or economics, a supplementary version of room and pillar mining, termed second mining or retreat mining ,

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1200-846: A new coal mine. La Francia La Francia is a coal mine in the Cesar-Ranchería Basin , located in the municipalities Becerril and El Paso , Cesar , Colombia owned by the Goldman Sachs Group. It mines coal from the Paleocene Los Cuervos Formation , time-equivalent with the Cerrejón Formation , which is mined in the northeastern part of the basin in Latin America's largest coal mine, Cerrejón . In 2016, La Francia produced 11.6 Megatons of coal. The mine

1300-677: A reduced thickness in the northern part of the Middle Magdalena Valley due to erosion, while the Paleocene section in the Cesar-Ranchería Basin is very thick. This has been explained by the tilt of the Sierra Nevada de Santa Marta and the formation of several thick-skinned thrust faults in the basin. The initiation of this compressive phase has been dated to the Maastrichtian , when tectonic uplift and deformation

1400-589: A result of occupational exposures is coined occupational hearing loss . To protect miners' hearing, the US Mine Safety and Health Administration 's (MSHA) guidelines for noise place a Permissible Exposure Limit (PEL) for noise at 90 dBA time-weighted over 8 hours. A lower cutoff, 85 dBA, is set for a worker to fall into the MSHA Action Level which dictates that workers be placed into hearing conservation programs. Noise exposures vary depending on

1500-590: A total production in 2016 of almost 33 Megatons. Other coal mines include La Francia , in the western Cesar portion of the basin. The total coal production of the Cesar-Ranchería Basin in 2016 was nearly 81 Megatons. The Cesar-Ranchería Basin is located at the northern edge of the South American Plate , close to the Caribbean Plate . During the Mesozoic and early Cenozoic eras, the basin

1600-575: Is accomplished by drilling holes into the overburden, filling the holes with explosives, and detonating the explosive. The overburden is then removed, using large earth-moving equipment, such as draglines , shovel and trucks, excavator and trucks, or bucket-wheels and conveyors. This overburden is put into the previously mined (and now empty) strip. When all the overburden is removed, the underlying coal seam will be exposed (a 'block' of coal). This block of coal may be drilled and blasted (if hard) or otherwise loaded onto trucks or conveyors for transport to

1700-454: Is associated with basinal relative sea level changes and the organic-rich strata to the Aptian anoxic event , dated to approximately 120 million years ago. The Lower Cretaceous series is followed by the deposition of the regional main source rock of northern Colombia and northwestern Venezuela, La Luna . The world class source rock contains high levels of Total Organic Carbon , comparable to

1800-427: Is commonly started. Miners remove the coal in the pillars, thereby recovering as much coal from the coal seam as possible. A work area involved in pillar extraction is called a pillar section. Modern pillar sections use remote-controlled equipment, including large hydraulic mobile roof-supports, which can prevent cave-ins until the miners and their equipment have left a work area. The mobile roof supports are similar to

1900-708: Is considered a major target for coal bed methane (CBM), due to the major coal deposits of the Los Cuervos and Cerrejón Formations. Total probable gas reserves for CBM are estimated at between 12.8 and 25.1 trillion cubic feet (360 × 10 ^ and 710 × 10 ^  m), Vitrinite reflectance data from several source rocks of the Cesar-Ranchería Basin show present-day mature to overmature Cretaceous formations ( La Luna , Aguas Blancas and Lagunitas Formations ) and (marginally) mature Paleocene source rocks, mainly Los Cuervos . Apatite fission track analysis and modeling combined with vitrinite reflectance data, showed

2000-418: Is dedicated to mining activities until it can be reshaped and reclaimed. If mining is allowed, resident human populations must be resettled off the mine site; economic activities, such as agriculture or hunting and gathering food and medicinal plants are interrupted. What becomes of the land surface after mining is determined by the manner in which the mining is conducted. Usually reclamation of disturbed lands to

2100-516: Is highly concentrated in certain jurisdictions, which also concentrates much of the social and economic impacts of the industry to these regions. The industry directly employs over seven million workers worldwide, which, in turn, creates millions of indirect jobs. In several parts of the world, producers have reached peak coal as some economies shift away from fossil fuels to address climate change. A 2020 study found that renewables jobs could feasibly be created in these geographies to replace many of

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2200-484: Is mostly used to generate electricity, and 75% of annual coal production is exported, mostly to eastern Asia. In 2007, 428 million tonnes of coal was mined in Australia. In 2007, coal provided about 85% of Australia's electricity production. In the fiscal year 2008/09, 487 million tonnes of coal was mined, and 261 million tonnes was exported. In the fiscal year 2013/14, 430.9 million tonnes of coal

2300-417: Is partially economically recoverable. Coal refuse is distinct from the byproducts of burning coal, such as fly ash . Piles of coal refuse can have significant negative environmental consequences, including the leaching of iron, manganese, and aluminum residues into waterways and acid mine drainage . The runoff can create both surface and groundwater contamination. The piles also create a fire hazard, with

2400-593: Is placed at the head of a narrow, steep-sided valley or hollow. In preparation for filling this area, vegetation and soil are removed and a rock drain constructed down the middle of the area to be filled, where a natural drainage course previously existed. When the fill is completed, this underdrain will form a continuous water runoff system from the upper end of the valley to the lower end of the fill. Typical head-of-hollow fills are graded and terraced to create permanently stable slopes. Most coal seams are too deep underground for opencast mining and require underground mining,

2500-626: Is produced from the Colón and La Luna Formations at the Maracas Field in the extreme southwest of the basin. A 2012 study of the yet-to-find potential of the Colombian sedimentary basins provided estimates of (P90-P10) 6 to 217 billion barrels (950 × 10 ^ to 34,500 × 10 ^  m) total generated oil in the Cesar-Ranchería Basin. The basin is considered to be the second-most prospective of Colombia in coal bed methane (CBM) with 25% of

2600-436: Is referred to as 'overburden' and is removed in long strips. The overburden from the first strip is deposited in an area outside the planned mining area and referred to as out-of-pit dumping. Overburden from subsequent strips is deposited in the void left from mining the coal and overburden from the previous strip. This is referred to as in-pit dumping. It is often necessary to fragment the overburden by use of explosives. This

2700-515: Is removed and overburden dumped to the side. Dust, vibration, and diesel exhaust odors are created (affecting sight, sound, and smell). Residents of local communities often find such impacts disturbing or unpleasant. In case of mountaintop removal , tops are removed from mountains or hills to expose thick coal seams underneath. The soil and rock removed is deposited in nearby valleys, hollows and depressions, resulting in blocked (and contaminated) waterways. Removal of soil and rock overburden covering

2800-616: Is sharply formed by the dextral strike-slip Oca Fault , while the Bucaramanga-Santa Marta Fault forms the boundary to the west. The faults form the border with the Guajira Basin and Middle Magdalena Valley respectively. The basin has a general orientation of 30 degrees from north. The Cesar-Ranchería Basin is subdivided into the Cesar Basin in the west, named after and hydrographically dominated by

2900-712: Is still common, with 4,000 new cases of black lung every year in the US (4 percent of workers annually) and 10,000 new cases every year in China (0.2 percent of workers). The use of water sprays in mining equipment reduces the risk to miners' lungs. Build-ups of a hazardous gas are known as damps, possibly from the German word Dampf which means steam or vapor: Noise is also a contributing factor to potential adverse effects on coal miners' health. Exposure to excessive noise can lead to noise-induced hearing loss . Hearing loss developed as

3000-464: Is the long wall, which involves using two spinning drums with carbide bits that runs along sections of the coal seam. Many coals extracted from both surface and underground mines require washing in a coal preparation plant . Technical and economic feasibility are evaluated based on the following: regional geological conditions; overburden characteristics; coal seam continuity, thickness, structure, quality, and depth; strength of materials above and below

3100-679: Is time-equivalent with the Girón Formation of the Eastern Ranges. The Early Cretaceous Río Negro Formation, a unit composed of sandstones, conglomerates and siltstones, is very variable in thickness in the basin and associated with continental sedimentation on rift shoulders to a post-rift setting. The formation is time-equivalent with the Tibasosa Formation of the Eastern Ranges and the Tambor Formation of

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3200-435: Is used for both thermal and metallurgical coals . In New South Wales open casting for steam coal and anthracite is practiced. Surface mining accounts for around 80 percent of production in Australia, while in the US it is used for about 67 percent of production. Globally, about 40 percent of coal production involves surface mining. Strip mining exposes coal by removing earth above each coal seam. This earth to be removed

3300-917: The Cesar River in the Magdalena River watershed, and the Ranchería Basin in the east. The latter is named after the Ranchería River flowing towards the Caribbean Sea and separated from the Cesar River by the intrabasinal Valledupar High, an extension of the Verdesia High. The southeastern edge of the basin is formed by the border with Venezuela . In total, the basin covers an area of 11,668 square kilometres (4,505 sq mi). The sedimentary sequence inside

3400-742: The Devonian and contain abundant fossils of brachiopods , bryozoa , corals and crinoids . The formation is time-equivalent with the fossiliferous Floresta and Cuche Formations of the Altiplano Cundiboyacense . The sediments were deposited in an epicontinental sea at the edge of the Paleo-Tethys Ocean , the last remnant of the Rheic Ocean . During the Early Carboniferous ( Pennsylvanian ),

3500-491: The Industrial Revolution , and coal provided the main source of primary energy for industry and transportation in industrial areas from the 18th century to the 1950s. Coal remains an important energy source. Coal is also mined today on a large scale by open pit methods wherever the coal strata strike the surface or are relatively shallow. Britain developed the main techniques of underground coal mining from

3600-728: The Kimmeridge Clay Formation of the basins of the North Sea . The ammonite -rich shales and biomicrites of La Luna were deposited during the global anoxic event of the Cenomanian - Turonian (around 90 Ma) characterised by a maximum flooding surface sequence. The highly organic formation is time-equivalent with the Querecual Formation of eastern Venezuela, the Chipaque and Gachetá Formations of

3700-481: The Maracaibo Basin and Middle Magdalena Valley . The first oil exploration was conducted in 1916 and several wells have been drilled since then. The basin is estimated to host the second-largest reserves of coal bed methane (CBM) of Colombia, with 25% of the country's total resources. The coal of the basin is mined in several quarries, most notably Cerrejón and La Francia . The total production of coal from

3800-597: The Ordovician - Silurian , Early Carboniferous and Early Permian respectively. The events were accompanied by acidic plutons found all across northern South America. Sediments from the Late Permian to Triassic periods are absent in the Cesar-Ranchería Basin, but evidenced in the surrounding orogens. Intense magmatism and metamorphism affected the Sierra Nevada de Santa Marta and the Central Ranges of

3900-599: The Paja Formation around Villa de Leyva , the most important fossiliferous stratigraphic unit of Colombia . The fossil flora and gigantic reptiles of the Cerrejón Formation provided abundant data on the paleo-ecology and climate of this first Neotropic environment of the Middle Paleocene. The Cesar-Ranchería Basin is underlain by Neoproterozoic basement. The Sierra Nevada Metamorphic Belt

4000-567: The Barco Formation, consisting of more lithic fragments than the equivalent of the Llanos Basin. Compression continued during the Paleocene, with uplifted areas to the northwest and southeast and volcanism in the proto-Caribbean. The global climate was very hot in this period and in the restricted basin between the two forming mountain ranges, a unique ecosystem developed; the first Neotropic forest. In this hot and humid environment,

4100-453: The Cerrejón Formation, the sediments of which are interpreted as representing the first Neotropic forest in the world. Mean annual temperature has been estimated to have been between 28.5 and 33 °C (83.3 and 91.4 °F) and yearly precipitation ranging from 2,260 to 4,640 millimetres (89 to 183 in) per year. The Cesar-Ranchería Basin is relatively underexplored for hydrocarbons, compared to neighbouring hydrocarbon-rich provinces as

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4200-516: The Cesar-Ranchería Basin experienced a regressional phase with the deposition of sandstones and limestones . The Early Permian is represented by the Manaure Formation, a sequence of sandstones and conglomerates . The formation of Pangea in the Late Permian to Early Triassic led to the formation of a metamorphic complex, named Sevilla. The gneisses , amphibolites , greenschists and marbles are dated to 280 to 250 Ma. The basin

4300-453: The Cesar-Ranchería Basin in 2016 was almost 81 Megatons. The name of the basin is taken from the Cesar and Ranchería Rivers . The Cesar-Ranchería Basin is an intermontane foreland basin enclosed by two main mountain ranges; the northernmost Andean Serranía del Perijá in the southeast of the basin and the triangular Sierra Nevada de Santa Marta to the northwest. The northeastern limit

4400-638: The Colombian Andes . The compressive phase is associated with the Hercynian orogeny , leading to the formation of Pangea . The break-up of Pangea in the Early Jurassic generated a sequence of rift basins in northern South America, surrounding the proto-Caribbean. The area of the present-day Serranía del Perijá was a continental rift, while basins to the west were marine in origin. Regional fault lineaments formed during this phase, that during

4500-682: The Colombian Eastern Ranges and Llanos Basin respectively and the Celendín Formation of northeastern Peru . The Late Cretaceous Molino Formation, laterally equivalent with the Colón and Mito Juan Formations of the Maracaibo and Catatumbo Basins , and the Umir Formation of the Middle Magdalena Valley, consists of calcareous shales intercalated by sandstones. The widespread correlation of this unit with

4600-586: The Cretaceous units have a significant potential for hydrocarbon generation. The Lagunitas and Aguas Blancas Formations are heavily fractured and considered a good potential fractured reservoir, while the Río Negro Formation has been analysed to be cemented and bearing low porosities . Coal mining in the Cesar-Ranchería Basin is concentrated in the northeast, with Cerrejón spanning the municipalities Albania , Barrancas and Hatonuevo , and in

4700-690: The Middle Magdalena Valley. The fossiliferous limestones and shales of the Lagunitas Formation, lower member of the Cogollo Group, contain beds of dolomite and are indicative of a shallow, saline environment. The formation is correlated with the Rosablanca Formation of the Middle Magdalena Valley and western Eastern Ranges and the Tibú Formation of the Maracaibo Basin . The unit is the deepest source rock for

4800-719: The Neogene conglomerates of the Cuesta Formation show a larger thickness in the southwestern part of the basin, close to the connected Middle Magdalena Valley. During this period, especially in the Late Miocene to Pliocene, the Oca and Bucaramanga-Santa Marta Faults were tectonically active, which is still observed in the present day. Ongoing uplift and reverse faulting created the intermontane fluvial-dominated basin architecture of today. Despite various detailed studies and

4900-664: The Ranchería Basin and in 1938 the first well (El Paso-1) was drilled in the Cesar Basin. The basin is relatively underexplored. The first 2D seismic lines were shot in the late 1970s and 1980s. The deepest well, El Paso-3, drilled to a total depth of 3,538 metres (11,608 ft) into the Cretaceous Aguas Blancas Formation . Oil extracted from the La Luna and Lagunitas Formations in the Papayal-1 well provided API gravities between 27 and 42. Gas

5000-812: The U.S., Examples include the Sago Mine disaster of 2006, and the 2007 mine accident in Utah 's Crandall Canyon Mine , where nine miners were killed and six entombed. In the decade 2005–2014, US coal mining fatalities averaged 28 per year. The most fatalities during the 2005–2014 decade were 48 in 2010, the year of the Upper Big Branch Mine disaster in West Virginia, which killed 29 miners. Chronic lung diseases, such as pneumoconiosis (black lung) were once common in miners, leading to reduced life expectancy . In some mining countries black lung

5100-569: The US Department of Labor's Mine Safety and Health Administration (MSHA) show that between 1990 and 2004, the industry cut the rate of injuries by more than half and fatalities by two-thirds. But according to the Bureau of Labor Statistics , even in 2006, mining remained the second most dangerous occupation in America, when measured by fatality rate . These numbers, however, include all mining activities, and oil and gas mining contribute to

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5200-549: The United States and proposed mines under development. The coal mining industry employs almost 2.7 million workers. The History of coal mining goes back thousands of years, with early mines documented in ancient China, the Roman Empire and other early historical economies. It became important in the Industrial Revolution of the 19th and 20th centuries, when it was primarily used to power steam engines, heat buildings and generate electricity. Coal mining continues as an important economic activity today, but has begun to decline due to

5300-439: The basin comprises Jurassic to Quaternary rocks, underlain by Paleozoic basement . An important unit is the Paleocene Cerrejón Formation , hosting major coal reserves, excavated in several open-pit mines of which Cerrejón in the northeast of the basin is the most striking. Cerrejón is the tenth biggest coal mine worldwide and the largest of Latin America. The formation provides low-ash, low-sulphur bituminous coal with

5400-403: The basin starts with the La Quinta Formation , that is found in a widespread area across northern Colombia and Venezuela. The formation of sandstones, basalts, conglomerates and volcanic ash was deposited in a lacustrine depositional environment in a rift basin setting related to the break-up of Pangea and has been dated to the Late Jurassic and earliest Cretaceous, 160 to 140 Ma. The formation

5500-414: The basin, the main compressional movement is dated to this phase, where reverse faults were formed. The stratigraphy of the Cesar-Ranchería Basin has been described by various authors. The coal producing area was mapped in 1961. In the Cesar-Ranchería Basin several important fossils have been found, most notably in the Cerrejón Formation, together with the Lagerstãtte of the Honda Group at La Venta and

5600-581: The coal mining jobs as part of a just transition ; however, renewable energy was not suitable in some of the geographies with high concentrations of miners, such as in China, which is far and away the leading coal-mining nation. Coal refuse (also described as coal waste, rock, slag, coal tailings, waste material, rock bank, culm, boney, or gob ) is the material left over from coal mining, usually as tailings piles or spoil tips . For every tonne of hard coal generated by mining, 400 kg (880 lb) of waste material remains, which includes some lost coal that

5700-497: The coal preparation (or wash) plant. Once this strip is empty of coal, the process is repeated with a new strip being created next to it. This method is most suitable for areas with flat terrain. Equipment to be used depends on geological conditions. For example, to remove overburden that is loose or unconsolidated, a bucket wheel excavator might be the most productive. The life of some area mines may be more than 50 years. The contour mining method consists of removing overburden from

5800-804: The coal resource may cause burial and loss of topsoil, exposes parent material, and creates large infertile wastelands. Soil disturbance and associated compaction result in conditions conducive to erosion. Soil removal from the area to be surface-mined alters or destroys many natural soil characteristics, and reduces its biodiversity and productivity for agriculture. Soil structure may be disturbed by pulverization or aggregate breakdown. Top 10 hard and brown coal producers in 2012 were (in million metric tons): China 3,621, United States 922, India 629, Australia 432, Indonesia 410, Russia 351, South Africa 261, Germany 196, Poland 144, and Kazakhstan 122. Coal has been mined in every state of Australia, but mainly in Queensland, New South Wales and Victoria. It

5900-418: The compression of the Andean orogenic stage were reactivated as thrust faults. The current compressional faults of the Cesar-Ranchería Basin are high-angle. The rift basin setting spanned the Jurassic period and was followed by post-rift sedimentation in the Early Cretaceous, evidenced by the Río Negro and Lagunitas Formations . During the Cretaceous, the basins of northern South America were connected in

6000-419: The country's total resources. Total probable gas reserves from this unconventional source have been estimated in 2014 at between 12.8 and 25.1 trillion cubic feet (360 × 10 ^ and 710 × 10 ^  m), up from an estimate ten years before of 6.9 trillion cubic feet (200 × 10 ^  m). The tectonic history of the Cesar-Ranchería Basin has been subdivided into six phases. The basin started as

6100-428: The deposition of the main source rock formations of the basin, most notably La Luna . A second phase of compressive margin has been noted in the Cesar-Ranchería Basin by the strong differences between the sedimentary thicknesses of the Paleocene formations. During this stage in the basin development, the Cesar-Ranchería Basin was connected to the Middle Magdalena Valley to the west. The Paleocene Lisama Formation has

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6200-429: The developed world. Modern coal mining in the US has an average 23 deaths per year due to mine accidents (2001–2020). However, in lesser developed countries and some developing countries, many miners continue to die annually, either through direct accidents in coal mines or through adverse health consequences from working under poor conditions. China , in particular, has the highest number of coal mining related deaths in

6300-455: The disruptive activities of blasting, ripping, and excavating coal. Stripping of overburden eliminates and destroys archeological and historic features, unless they are removed beforehand. The removal of vegetative cover and activities associated with the construction of haul roads, stockpiling of topsoil, displacement of overburden and hauling of soil and coal increase the quantity of dust around mining operations. Dust degrades air quality in

6400-424: The early days of men tunneling, digging, and manually extracting the coal on carts to large open-cut and longwall mines. Mining at this scale requires the use of draglines , trucks, conveyors , hydraulic jacks , and shearers. The coal mining industry has a long history of significant negative environmental impacts on local ecosystems, health impacts on local communities and workers, and contributes heavily to

6500-571: The fatalities occurring in the first half of the 20th century. 3,242 died in 1907, the worst year ever; in 2020 there were five. Open cut hazards are principally mine wall failures and vehicle collisions; underground mining hazards include suffocation, gas poisoning, roof collapse, rock burst , outbursts , and gas explosions. Firedamp explosions can trigger the far more dangerous coal dust explosions, which can engulf an entire mine. Most of these risks are greatly reduced in modern mines, and multiple fatality incidents are now rare in most parts of

6600-457: The genetic soil profile, displaces or destroys wildlife and habitat, alters current land uses, and to some extent permanently changes the general topography of the area mined. Adverse impacts on geological features of human interest may occur in a coal strip mine. Geomorphic and geophysical features and outstanding scenic resources may be sacrificed by indiscriminate mining. Paleontological, cultural, and other historic values may be endangered due to

6700-497: The giant crocodylians Cerrejonisuchus improcerus , Anthracosuchus balrogus and Acherontisuchus guajiraensis , and the large turtles Carbonemys cofrinii , Puentemys mushaisaensis and Cerrejonemys wayuunaiki . Various genera of flora, as Aerofructus dillhoffi , Menispermites cerrejonensis , M. guajiraensis , Montrichardia aquatica , Petrocardium cerrejonense and P. wayuuorum , Stephania palaeosudamericana and Ulmoidicarpum tupperi among others, have been found in

6800-399: The global environmental crises, such as poor air quality and climate change . For these reasons, coal has been one of the first fossil fuels to be phased out of various parts of the global energy economy . The major coal producing countries, though, such as China , Indonesia, India and Australia , have not reached peak production, with production increases replacing falls in Europe and

6900-450: The immediate area, has an adverse impact on vegetative life, and constitutes health and safety hazards for mine workers and nearby residents. Surface mining disrupts virtually all aesthetic elements of the landscape. Alteration of land forms often imposes unfamiliar and discontinuous configurations. New linear patterns appear as material is extracted and waste piles are developed. Different colors and textures are exposed as vegetative cover

7000-413: The largest species of reptiles since the extinction of the dinosaurs evolved, of which Titanoboa was the main predator. It has been estimated on the basis of the fossil flora, pollen and large reptiles that the mean annual temperature was between 28.5 and 33 °C (83.3 and 91.4 °F) and yearly precipitation ranging from 2,260 to 4,640 millimetres (89 to 183 in) per year. Provenance analysis of

7100-460: The late 18th century onward, with further progress being driven by 19th-century and early 20th-century progress. However, oil and gas were increasingly used as alternatives from the 1860s onward. By the late 20th century, coal was, for the most part, replaced in domestic as well as industrial and transportation usage by oil , natural gas or electricity produced from oil, gas, nuclear power or renewable energy sources. By 2010, coal produced over

7200-404: The majority of fatalities. Coal mining resulted in 47 fatalities that year. One study, though, has suggested that hazards of modern mining are now more accretive with workers facing long-term health impacts, such as sleep deprivation, that build up over time. Strip mining severely alters the landscape, which reduces the value of the natural environment in the surrounding land. The land surface

7300-461: The method of extraction. For example, a study has found that among surface coal mine operations, dragline equipment produced the loudest sound at a range of 88–112 dBA. Within longwall sections, stageloaders used to transport coal from the mining face and shearers used for extraction represent some of the highest noise exposures. Auxiliary fans (up to 120 dBA), continuous mining machines (up to 109 dBA), and roof bolters (up to 103 dBA) represent some of

7400-465: The mining workforce. in 2015 US coal mines had 65,971 employees, the lowest figure since EIA began collecting data in 1978. However, a 2016 study reported that a relatively minor investment would allow most coal workers to retrain for the solar energy industry. Coal mining has been a very dangerous activity and the list of historical coal mining disasters is long. In the U.S., 104,895 coal miners were killed in mine accidents since 1900, 90 percent of

7500-624: The neighbouring formations indicates an open marine environment all across northwestern South America. At the end of the Cretaceous, the tectonic regime changed to a compressive phase, due to the movement of the Caribbean Plate. The Early Paleocene deposits of the Hato Nuevo and Manantial Formations show a more calcareous character in the north, while the Cesar Sub-basin contained more siliclastic sedimentation, represented in

7600-469: The noisiest equipment within continuous mining sections. Exposures to noise exceeding 90 dBA can lead to adverse effects on workers' hearing. The use of administrative controls and engineering controls can be used to reduce noise exposures. Improvements in mining methods (e.g. longwall mining), hazardous gas monitoring (such as safety-lamps or more modern electronic gas monitors), gas drainage, electrical equipment , and ventilation have reduced many of

7700-533: The north is estimated to have been active since the Early Eocene with a total displacement of 180 kilometres (110 mi). The Bucaramanga-Santa Marta Fault was a Jurassic extensional rift fault, reactivated as oblique reverse fault in the Oligocene . Petroleum exploration in the Cesar-Ranchería Basin commenced in 1916. The first exploitation of hydrocarbons was performed in 1921 and 1922 at Infantas in

7800-506: The oils in the Cesar-Ranchería Basin. The upper member of the Cogollo Group, the Aguas Blancas Formation, presents a large lateral variability in lithologies. Black biomicrites and fossiliferous limestones are indicative of a middle to outer platform environment, while sandy shales and glauconitic sandstones indicate a shallow marine environment. The variation in lithologies and organic content of this source rock formation

7900-590: The open pit methods, due to thickness of the seam 20–25 metres (60–90 feet). Coals occurring below 90 m (300 ft) are usually deep mined. However, there are open pit mining operations working on coal seams up to 300–460 metres (1,000–1,500 feet) below ground level, for instance Tagebau Hambach in Germany. When coal seams are near the surface, it may be economical to extract the coal using open-cut , also referred to as open-cast, open-pit, mountaintop removal or strip, mining methods. Opencast coal mining recovers

8000-421: The operation reaches a predetermined stripping ratio (tons of overburden/tons of coal), it is not profitable to continue. Depending on the equipment available, it may not be technically feasible to exceed a certain height of highwall. At this point, it is possible to produce more coal with the augering method in which spiral drills bore tunnels into a highwall laterally from the bench to extract coal without removing

8100-408: The overburden. Mountaintop coal mining is a surface mining practice involving removal of mountaintops to expose coal seams, and disposing of associated mining overburden in adjacent "valley fills." Valley fills occur in steep terrain where there are limited disposal alternatives. Mountaintop removal mining combines area and contour strip mining methods. In areas with rolling or steep terrain with

8200-488: The potential to spontaneously ignite. Because most coal refuse harbors toxic components, it is not easily reclaimed by replanting with plants like beach grasses. The use of sophisticated sensing equipment to monitor air quality is common and has replaced the use of small animals such as canaries, often referred to as " miner's canaries ". In the United States, the increase in technology has significantly decreased

8300-399: The risks of rock falls, explosions, and unhealthy air quality. Gases released during the mining process can be recovered to generate electricity and improve worker safety with gas engines . Another innovation in recent years is the use of closed circuit escape respirators , respirators that contain oxygen for situations where mine ventilation is compromised. Statistical analyses performed by

8400-418: The seam for roof and floor conditions; topography, especially altitude and slope; climate; land ownership as it affects the availability of land for mining and access; surface drainage patterns; groundwater conditions; availability of labor and materials; coal purchaser requirements in terms of tonnage, quality, and destination; and capital investment requirements. Surface mining and deep underground mining are

8500-565: The seam in a pattern following the contours along a ridge or around the hillside. This method is most commonly used in areas with rolling to steep terrain. It was once common to deposit the spoil on the downslope side of the bench thus created, but this method of spoil disposal consumed much additional land and created severe landslide and erosion problems. To alleviate these problems, a variety of methods were devised to use freshly cut overburden to refill mined-out areas. These haul-back or lateral movement methods generally consist of an initial cut with

8600-508: The sediments of the Los Cuervos and Cerrejón Formations show a predominant west to east paleocurrent, followed by a more southeastern flow. A secondary source of sediments was the growing Serranía del Perijá. During the Eocene and Early Oligocene, the western part of the basin was exposed and modest deposition concentrated in the Ranchería Sub-basin. The previously humid ecosystem changed to an arid plain environment. In contrast,

8700-509: The similarities with neighbouring hydrocarbon rich provinces as the Maracaibo , Catatumbo and Middle Magdalena Basins , the Cesar-Ranchería Basin is relatively underexplored. Minor gas production is centered in the south of the Cesar Sub-basin, but most exploration wells were drilled before the 1950s. As of 2007, 14 wells were drilled in the basin. A major project to reprocess and interpret 2D seismic lines has been conducted in 2006. The basin

8800-524: The southwest, with La Francia in the municipalities Becerril and El Paso . At Cerrejón, the coal is excavated from the Cerrejón Formation and in La Francia from the time-equivalent Los Cuervos Formation . Coal is also mined in Agustín Codazzi , Chiriguaná and La Jagua de Ibirico . The total coal production of the Cesar-Ranchería Basin in 2016 was nearly 81 Megatons. Minor gold mining

8900-432: The spoil deposited downslope or at some other site and spoil from the second cut refilling the first. A ridge of undisturbed natural material 15 to 20 ft (5 to 6 m) wide is often intentionally left at the outer edge of the mined area. This barrier adds stability to the reclaimed slope by preventing spoil from slumping or sliding downhill. The limitations of contour strip mining are both economic and technical. When

9000-556: The strong contribution coal plays in global warming and environmental issues, which result in decreasing demand and in some geographies, peak coal . Compared to wood fuels , coal yields a higher amount of energy per unit mass, specific energy or massic energy, and can often be obtained in areas where wood is not readily available. Though it was used historically as a domestic fuel, coal is now used mostly in industry, especially in smelting and alloy production, as well as electricity generation . Large-scale coal mining developed during

9100-476: The surface or overburden, of the mining area. The overburden is then removed by draglines or by shovel and truck. Once the coal seam is exposed, it is drilled, fractured and thoroughly mined in strips. The coal is then loaded onto large trucks or conveyors for transport to either the coal preparation plant or directly to where it will be used. Most open cast mines in the United States extract bituminous coal . In Canada, Australia, and South Africa, open cast mining

9200-524: The two basic methods of mining. The choice of mining method depends primarily on depth, density, overburden, and thickness of the coal seam; seams relatively close to the surface, at depths less than approximately 55 m (180 ft), are usually surface mined. Coal that occurs at depths of 55 to 90 m (180 to 300 ft) are usually deep mined, but in some cases surface mining techniques can be used. For example, some western U.S. coal that occur at depths in excess of 60 m (200 ft) are mined by

9300-441: The world, with official statistics claiming that 6,027 deaths occurred in 2004. To compare, 28 deaths were reported in the U.S. in the same year. Coal production in China is twice that in the US, while the number of coal miners is around 50 times that of the US, making deaths in coal mines in China 4 times as common per worker (108 times as common per unit output) as in the US. Mine disasters have still occurred in recent years in

9400-701: Was intruded by granites during the Early to Middle Jurassic being accompanied by volcanics and volcanoclastic sediments such as the basalts , tuffs , sandstones and breccias found in the Sierra Nevada de Santa Marta . This magmatic phase correlated with the sedimentary sequence of the La Ge Group, subdivided into the Tinacoa and Macoíta Formations, a series of tuffaceous sandstones, limestones, shales and siltstones . The sedimentary sequence drilled in

9500-612: Was active in Valledupar in 2008. A study published in 2015 on the La Quinta Formation , shows the presence of 1.45% of copper , present mainly in malachite mineralisations in the volcanoclastic beds of the formation. Coal mine Coal mining is the process of extracting coal from the ground or from a mine. Coal is valued for its energy content and since the 1880s has been widely used to generate electricity. Steel and cement industries use coal as

9600-616: Was active in the Central Ranges , to the west of the basin. While the Llanos Basin to the southeast experienced a foreland basin setting since the Paleogene, due to the first phases of uplift of the Eastern Ranges , the Cesar-Ranchería Basin was characterised by an intermontane basin setting with forming mountain ranges to the north and southeast; the Sierra Nevada de Santa Marta and Serranía del Perijá respectively. Inside

9700-775: Was connected to the Magdalena River basins ( Middle and Lower Magdalena Valleys ) and the Sinú-Jacinto Basin in the west and the Maracaibo Basin , of which the Catatumbo Basin forms the Colombian part, in the east. Compressional tectonic movement commenced in the Late Paleogene , creating an intermontane foreland basin enclosed by the Serranía del Perijá and the Sierra Nevada de Santa Marta. The east-west oriented dextral strike-slip Oca Fault in

9800-752: Was formed during the Grenville orogeny , when the supercontinent Rodinia was formed due to the collision of Amazonia , Baltica and Laurentia . The granulites and gneisses of the complex metamorphosed 1.5 to 1.0 billion years ago. The phyllites and quartzites of the Perijá Formation were formed during the Early Paleozoic and are related to the Caledonian orogeny . The shales of the Río Cachirí Group were deposited in

9900-531: Was mined, and 375.1 million tonnes was exported. In 2013/14, coal provided about 69% of Australia's electricity production. In 2013, Australia was the world's fifth-largest coal producer, after China, the United States, India, and Indonesia. However, in terms of proportion of production exported, Australia is the world's second largest coal exporter, as it exports roughly 73% of its coal production. Indonesia exports about 87% of its coal production. A court in Australia has cited climate change in ruling against

10000-521: Was owned by Coalcorp Mining until 2010. It was acquired by Goldman Sachs for US$ 200 million in 2010. It closed in January 2013 after the contractor hired by Colombian National Resources opted out, but opened again in January 2014, at a lesser capacity. During the strikes of 2013, miners occupied the mine and refused offers provided by the companies involved. In 2015, Murray Energy (now known as American Consolidated Natural Resources ) purchased

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