Coal Formation and the Origin of Coal Fires

Kim, Ann G.

doi:10.1016/b978-0-444-52858-2.00001-3

Cited by 9 publications

(2 citation statements)

References 35 publications

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“…Coal-bearing siliciclastic sediments on outcrops are susceptible to weathering and have a propensity to self-heat and self-ignite [19]. In coalfields, these processes also occur in opencast and underground mines, especially in coal stockpiles and coal-bearing waste dumps [20][21][22][23].…”

Section: Weathering and Thermally Altered Coal-bearing Depositsmentioning

confidence: 99%

The Disappearance of Coal Seams Recorded in Associated Gangue Rocks in the SW Part of the Upper Silesian Coal Basin, Poland

et al. 2021

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Coal seams in the Upper Silesian Coal Basin vanish within the Carboniferous Upper Silesian Sandstone Series and below an unconformity marking the Carboniferous top surface. Changes in the geochemical, mineralogical, petrological and palynological characteristics of gangue rocks associated with the vanished seams record what happened. The observed changes could have been caused by (1) coal-seam paleofire, (2) peat combustion, (3) igneous intrusion, (4) metasomatism and/or (5) weathering. Multifaceted research on samples collected at the Jas-Mos mining area, a part of the operating Jastrzębie-Bzie Coal Mine that are representative of different geological settings in the northern and southern parts of the mining area, point to intra-deposit paleofire as the most plausible reason for the disappearance. Biomarkers enabled recognition of differences in heating duration and oxygen access. Coal seams in the south burned quickly with abundant oxygen supply. Seams in the north pyrolyzed for an extended time under conditions of limited oxygen. Though other methods used proved less sensitive, all confirmed low (100–150 °C) paleotemperature heating. Overall, the reason for the local disappearance of the coal seams, making their exploitation difficult and unprofitable, can be assigned to a variety of different processes in a complex overlapping history of variable weathering, heating due to local endogenic fires and, probably, earlier peat combustion.

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Section: Weathering and Thermally Altered Coal-bearing Depositsmentioning

confidence: 99%

The Disappearance of Coal Seams Recorded in Associated Gangue Rocks in the SW Part of the Upper Silesian Coal Basin, Poland

et al. 2021

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“…The most common subsurface fires occur in peat beds [3][4][5], coal deposits [6][7][8][9][10][11][12], dumps from coal mines [13][14][15], mud volcanoes [16][17][18] and bituminous sediments [2,[19][20][21][22][23][24][25][26][27][28][29][30]. A particular case of subsurface fires is described in lakes with predominantly diatomitic sedimentation that are desiccated during drought periods [29].…”

Section: Introductionmentioning

confidence: 99%

Pyrometamorphic Rocks in the Molinicos Basin (Betic Cordillera, SE Spain): Insights into the Generation of Cordierite Paralavas

et al. 2019

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A singular thermal anomaly occurred in the Molinicos Miocene, lacustrine, intramontane basin (Betic Cordillera). This gave place to vitreous vesicular materials (paralavas) and baked rocks (clinker) inside of a sequence of marly diatomites and limestones. The chemical composition of the paralavas (SiO 2 = 52-57, Al 2 O 3 ≈ 20, Fe 2 O 3 = 10-20, K 2 O + Na 2 O < 2.5, CaO < 4.5, and MgO < 1.5, % in weight), which is very different from typical igneous rocks, and their high-T mineralogy (cordierite, sillimanite, anorthite, mullite, and high-T silica polymorphs) suggest that they formed during a pyrometamorphic event. The occurrence of dry intervals in the lacustrine depositional system, the high Total Organic Carbon contents (>4% in weight) of dark clay layers and the existence of tectonic fractures give the right context for a combustion process. Short-term heating favoured the generation of paralavas, clinker and marbles. Thermodynamic modelling constrains the onset of melting at 870-920 • C for <10 MPa at equilibrium conditions. However, the presence of tridymite and/or cristobalite in clinker and paralavas and the compositional variation in both rock types suggests that the temperature at which first melting occurred ranged between 870 • C and 1260 • C due to melt fractionation processes.Minerals 2019, 9, 748 2 of 24 evacuation of combustion products [22]. At the same time, thermal isolation is necessary to accumulate locally enough heat until an activation threshold is reached [29]. Thus, depth and extension of the fires are commonly restricted to some tens of square metres, limited in addition by the position of the water table. However, much larger areas have been described reaching hundreds of square kilometres [22].During combustion metamorphism, the sedimentary rocks around the ignition foci are subjected to certain changes in addition to common dehydration, and decarbonation in case CaCO 3 is present. Firstly, the rocks are hardened and, later, they become sintered and recrystallised producing a ceramic texture. The colour of the rocks is also progressively changed from yellow to more intense orange and red, due to iron oxidation, and finally even grey and black when reducing conditions are reached. In any case, this intense thermal metamorphism triggers only limited fusion of the sediments. The released melts may flow along fractures but usually undergo fast cooling producing small amounts of glass with particular mineral assemblages and textures similar to those of fine-grained volcanic rocks. These rocks, which show features and parageneses merging with those of igneous rocks, are called paralavas and the associated baked or partially melted sedimentary rocks are denominated clinker e.g., [24,[31][32][33][34]. According to Cosca and Essene [35] the mineral assemblages produced in paralavas are partly a function of the temperature, degree of partial melting, and oxidation state related to local gas buffers, in addition to the original bulk composition of the sedimentary protolith. Fast heating and subs...

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Optimization of techniques for the extinction and prevention of coal fires produced in final walls as a result of spontaneous combustion in the Cerrejón mine—Colombia

Rúa

Baena

Aragón

2018

Environ Sci Pollut Res

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Coal Formation and the Origin of Coal Fires

Cited by 9 publications

References 35 publications

The Disappearance of Coal Seams Recorded in Associated Gangue Rocks in the SW Part of the Upper Silesian Coal Basin, Poland

The Disappearance of Coal Seams Recorded in Associated Gangue Rocks in the SW Part of the Upper Silesian Coal Basin, Poland

Pyrometamorphic Rocks in the Molinicos Basin (Betic Cordillera, SE Spain): Insights into the Generation of Cordierite Paralavas

Optimization of techniques for the extinction and prevention of coal fires produced in final walls as a result of spontaneous combustion in the Cerrejón mine—Colombia

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