An extensive study of the coal mining records, borehole data and underground exposures has provided useful information relating to this area of the Coalfield. The stratigraphic information indicates this area was marginal within the Westphalian basin of deposition. Marine incursions are sometimes multiple and indicate, along with other sedimentary features that the Vale of Neath Disturbance was active throughout the Westphalian as a positive area: there was similar activity around the Taw Valley Disturbance. Newly constructed ideal cyclothems indicate an oscillating delta front from mid Westphalian C onwards so that mesothems replace cyclothems as the basic unit of sedimentation: they also indicate the changing palaeo-environment. Structural information suggests that the present extent of Pennant Sandstone outcron is as it was during the Armorican Orogeny. The Tawe Valley and Vale of Neath Disturbances have probably formed over basement Caledonian faults and were active prior to and throughout the orogeny with possible Neogene movement. An early tensional phase created the normal cross-faults and later compressional deformation took place within the individual fault blocks. The Coalfield was compressed against a northern rigid area resulting in the north-easterly movement of the area between the caledonoid disturbances driving the measures at the margin before it on an imbricate fan and compressional and incompetent structures. The stress-field was resolved and relieved locally by a variety of incompetent structures including the newly described Rotary Faults.

No description available.

Making and Breaking Big Rural: Science and Technology Construct the Coalfield examines science and technology research and its role in constructing a rural industrial space such as the Pocahontas Coalfield in Southern West Virginia/Southwest Virginia. It examines the ramifications of this single sector rural space, and of automation and coalfield technology, on its inhabitants, especially on their capacity for democratic practice. In a call for science and research for public benefit, it proposes how scientific and technological research ought to engage with the people and the environment in this rural industrial space, and in the rural space more generally. Using a case study of the Pocahontas Coalfield as a springboard, a draft of a National Rural Strategy for the United States also is proposed. / Ph. D.

M.Sc. / Please refer to full text to view abstract

South Africa remains the 5th largest producer and 4th largest exporter of coal in the world. It is also the largest supplier of coal to the European Union. This fact is significant as the European Union has recently supported the environmental lobby that threatens the combined full scale use of coal in Europe and other first world countries. This promotes the development of clean coal technologies in order to counter the ever increasing number of environmental constraints threatening the export market. One critical development in clean coal technologies is coal beneficiation, which allows the reduction of ash and inert content. Permian coals from South Africa have characteristically high ash and inertinite contents and therefore require further beneficiation. The Witbank coalfield No. 4 seam is no exception. It can be described as being more inert and having a higher mineral content compared to the No. 2 seam in the same coalfield also mined for export purposes. With the increase in environmental legislation and the push towards “clean coal” this raises a concern in terms of the performance and marketability of export coal produced from the No. 4 seam. This seam will in the future be economically significant and is still a great source for export steam coal. Due to the nature and composition of the No. 4 seam, coal beneficiation is essential to reduce the mineral and inert content to be in line with export quality specification levels. Washability characteristics of the No. 4 seam coal indicate that the No. 4 seam is difficult to beneficiate. Until recently the main clean-ability parameters evaluated in South African export coals as per customer specification included mainly heating value, moisture and ash reduction with little to no work being done on trace element concentration reduction. This paper focuses on the partitioning of the trace elements within the seam in relation to the organic and inorganic affinity of the trace elements and possible methods of trace element reduction by removal using coal beneficiation techniques. The techniques investigated include reduction by washing using dense medium beneficiation and flotation. In each evaluation the focus was on trace-element-tomineral and trace-element-to-organic matter relationship and hence setting the basis for liberation analysis to evaluate reducibility. By the evaluation of the coal mineralogy, petrography and trace element relationships, methods of optimum trace element reduction can be established. With the focus on marketing it was shown that carbon loss need not be sacrificed in the reduction of specific trace elements in the No. 4 seam and that the trace element distribution itself allows for beneficiation whilst maintaining acceptable yields. Processes and possible beneficiation techniques for optimum trace element reduction and marketability in the case of the No.4 seam are proposed.

The exploration for unconventional energy reserves has rapidly increased over the last five to ten years. Currently, there are a number of companies actively exploring for coalbed methane (CBM) in New Zealand. This study investigates one of these prospects, the subbituminous Huntly coalfield. Coal core was retrieved from the two major seams in the coalfield, the Renown and the Kupakupa. Three coals types were identified (1) bright lustre, non-banded, (2) bright lustre, moderately banded and (3) bright lustre, highly banded. As the degree of banding increases, the average thickness of the vitrain bands increase, the amount of structured vitrinite macerals also increase and the vitrodetrinite content decreases. The Renown seam is predominantly composed of bright non-banded coal while in the Kupakupa seam the more banded coal types are dominant. On average, the Renown seam has both the capacity to hold more gas and has higher gas contents than the stratigraphically lower Kupakupa seam. Additionally, gas content, on average, was found to be highest in intervals of the non-banded coal type and lowest in the highly banded coal type. Cluster analysis found that gas content is associated with hydrogen, volatile matter, calorific value and collodetrinite. As such, gas appears to be preferentially retained/produced in the matrix-dominated material. While not causally linked with gas content, gas holding capacity showed associations with the sporinite, inertodetrinite, funginite and vitrodetrinite; of note, these macerals are highest in the non-banded coal type. Gas holding capacity is thought to be a function of coal texture. Ash yield was found to inversely affect total gas content when ash yield is >10%. Below 10%, it is thought that inorganic elements are organically bound. The small angle scattering analysis indicated that inorganic matter was in the 12.5 Å < r < 125 Å pore size range. The influence of inorganic material was more noticeable in vitrain than matrix samples and is proposed to exist as thin inorganic coatings. Total porosity of the Huntly coal is primarily composed of micropores with macroporosity only contributing a small proportion. In addition, the specific surface area of the coals is also largely contributed by the micropores. Methane holding capacity on a dry, ash-free basis showed positive correlations with both micro- and macroporosity. When methane holding capacity was considered on an ‘as analysed’ basis, correlation was only identified with macroporosity. Possibly gas holding capacity is affected by the presence of moisture blocking access to gas adsorption sites in smaller pores. Considerable variation is present in both gas adsorption and gas desorption results between drill holes, between seams and also within individual seam intersections. Gas adsorption capacity and gas content are used to calculate % saturation for a reservoir, a key assessment parameter. It was found that multiple samples of both gas adsorption capacity and gas content are required to reduce the uncertainty around the calculated % saturation (at least three of each in the current study). Additionally, adsorption isotherm samples need to be collected as fresh as possible to minimize oxidation and moisture loss. Delaying sample analysis was found to result in an overestimation of gas adsorption capacity.

The main objective of this work is to aid coal mine planning by determining geological structures that affect mining such as faults, dykes and sills. Faults can displace the coal seams by breaking and throwing the coal seam on one side of the fault deeper; thereby constituting safety risks or even making exploitation uneconomical. Dykes are associated with devolatilisation of the coal around them. Both dykes and faults are also important in terms of groundwater management. The sills have the same devolatilisation effect as dykes but on a larger scale as they cover more area than the dykes. They also make mining difficult if one has to mine through them, especially if they are not weathered. The study was based on high resolution airborne magnetic data which was flown on selected areas in the Witbank coalfield. The combined areas cover a total of ~171001 hectares. Total field magnetic data were collected. The data were processed and gridded. The resulting total field magnetic grids were enhanced for better delineation of structures by: reducing the data to the pole, calculation of the first vertical derivatives and computation of the analytic signal. Using the enhanced grids together with other datasets; topographic maps, borehole log information and infrastructure information from the surrounding mines, the geological structures were interpreted. Intense geological activity is observed on the eastern areas of the coalfield (Belfast and Arnot). This is the region where numerous geological activities of different ages were recorded, e.g., the intrusion of Bushveld Complex, the Olifants River Dyke Swarm (ORDS) and the Karoo Basalts. Associated with the intense geological activity is the presence of dykes, faults and sills, which are observed throughout the areas. In the central region, Vandyksdrif area 1 reveals the pre-Karoo basement rocks (felsites and diabases of the Bushveld Igneous Complex) and Vandyksdrif area 2 reveals the Karoo dolerite in the form of a sill. The sill corresponds to the high elevation area on the digital terrain model data suggesting that the sill might be unweathered. Unfortunately, the borehole logs do not mention the state of the dolerite. The western areas reveal mainly the dolerite sill. Like in Vandryksdrif area 2, there is no mention of the state of the dolerite and the suspicion is that the dolerite is also unweathered there as well. Copyright / Dissertation (MSc)--University of Pretoria, 2010. / Geology / unrestricted

Thesis (M. Sc. (Geology)) --University of Limpopo, 2021 / The Madzaringwe Formation in the Tuli Basin, Limpopo Province of South Africa is one of the coal-bearing late Palaeozoic units of the Karoo Supergroup. The Madzaringwe Formation in the former Vele colliery (now referred to as Vele MC Mining) is the focus of this study and it consists of sandstone and shale with thin coal seams. To date, published data gives an overview of the stratigraphy of the Madzaringwe Formation in the Tuli coalfield. Little is known of the petrographic characteristics, lithofacies and geochemistry of the Madzaringwe Formation. Hence, this research work is undertaken to better define the lithological characteristics, provenance and tectonic setting of the Madzaringwe Formation in the Vele Colliery, Limpopo Province, South Africa. In the Vele colliery, the Tshidzi Formation forms the base of the Karoo sequence, consisting of diamictite and attains a maximum thickness of about 10 m. The Madzaringwe Formation overlies the Tshidzi Formation and it is made up of shale, mudstone and sandstones with subordinate siltstones and coal seams. Succeeding the Madzaringwe Formation is the Mikambeni Formation, comprising of black carbonaceous shale, mudstone and sandstones with minor coal layers. The Fripp Formation overlies the Mikambeni Formation and it consists of sandstones with subordinate grey mudstones and attains a maximum thickness of about 15 m. The Madzaringwe, Mikambani and Fripp Formations in the Vele colliery can be correlated with the Ecca Group of the main Karoo Basin. Based on the detailed sedimentological analyses of borehole and open pit data, ten lithofacies were identified and four facies associations (FAs) were recognised. The facies associations are: FA 1: Carbonaceous and pyritic shale and mudstones (Fls + Fss), FA 2: Black coal and shaly coal (C + Cs), FA 3: Dark grey micaceous and calcareous shale and mudstone, with subordinate siltstones (Fls + Fm, Fc + Fms + Fmb), and FA 4: Siltstone intercalated with fine to coarse grained sandstones (Fms + Fss + Sm + D). Sedimentological characteristics of the identified facies associations indicate shallow lake and floodplain depositional environments. The petrographic characterization revealed that vitrinite is the dominant maceral group in the coals, making up to 81-92 vol.% (mmf) of the total sample. Collotellinite is the dominant vitrinite maceral, with total count varying between 52.4 vol.% (mmf) and 74.9 vol.% (mmf), followed by corpogelinite, collodetrinite, tellinite and pseudovitrinite with count ranging between 0.8-19.4 vol.% (mmf), 1.5-17.5 vol.% (mmf), 0.8-6.5 vol.% (mmf) and 0.3-5.9 vol.% (mmf), respectively. The dominance of collotellinite gives a clear indication that the coals are derived from the parenchymatous and woody tissues of roots, stems and leaves. The mean random vitrinite reflectance values range between 0.75 and 0.76%, placing the coals in the medium rank category (also known as the high volatile bituminous coal) based on the UN-ECE coal classification scheme. The high amount of inertinite, especially fusinite with empty cells and semifusinite in the coals will pose a threat to coal mining because it aids the formation of dust. The sandstones of the Madzaringwe Formation are classified as sub-arkoses and sub-litharenites. Petrographic and geochemical analyses of the mudrocks and sandstones show that the rocks are from silicic or felsic igneous rocks. The tectonic setting discrimination diagrams support passive-active continental margin settings of the provenance. The indices of weathering/alteration and the binary plot of the index of compositional variability (ICV) against chemical index of alteration shows that the studied samples have been subjected to moderate to intensive weathering. Keywords: Geology, geochemistry, Madzaringwe Formation, Tuli Coalfield, South Africa

This thesis examines the development of health and safety in the British coalmining industry in the period of rapid expansion 1840 to 1913 through a case study of the Warwickshire coalfield. It will assess the contribution of the miner, the coalowners and the State to improvements to mine safety. Although historians have been attracted to this period of coalfield expansion, they have tended to concentrate upon the complex economics necessary for success or the fractious record of industrial relations, with health and safety marginalised to the periphery. They have also mainly taken their exemplars from the important coal exporting activities of the North-East and South Wales, together with the larger coalfields of Scotland, Lancashire, Yorkshire and Nottinghamshire. By studying the Warwickshire fatalities and comparing that experience with the neighbouring counties of the East Midlands and national data, this thesis will reveal how local factors influenced safety in the mines. The individual miner had little influence upon mine safety in the period 1840 through to the mid 1870's when the sub-contracting butty system removed owners from the responsibilities of production. The establishment of a permanent Warwickshire Miners’ Association from the 1880’s, characterised by moderate leadership who sought to work closely with employers, gained for the Warwickshire miner superior earnings and conditions of employment, even when compared to neighbouring coalfields in the prosperous Midland Division. This undermines the national caricature of coalowners as brutal capitalists with little regard for their workers or communities where they gained their wealth. The results showed conclusively that it was not the mode of management but the size of the enterprise that was the dominating factor. Fatalities increased in the large deep mines that became more common at the turn of the century and were more susceptible to deaths from falls of coal and men crushed by wagons on the surface. The role of the State was somewhat patchy. Mine Inspectors could recommend that horses employed in oncost haulage should work in shafts rather than chains and that low tension batteries should be used to bring down coal, but owners were free to ignore this advice, with fatal consequences to the workforce. They were more successful in promoting the professionalization of mine management and at the turn of the century legislation was the dominant factor in the adoption of patent explosives to replace the use of gunpowder in Warwickshire mines. This thesis builds upon recent studies by McIvor and Mills which have sought to address this neglect of health and safety in the British coal mining industry. By approaching this through the study of a small coalfield that has largely been ignored by mining historians, it reveals how local factors influenced the contribution of the miner, the coalowner and the State to the problem of accidents and fatalities in the coal industry.

As camadas de carvão de idade Permiana da Formação Rio Bonito de Candiota constituem o maior depósito do país. Atualmente são mineradas duas camadas, denominadas “Camada Candiota Superior” e “Camada Candiota Inferior”. As outras camadas, S1-S9 (camadas superiores) e I1-I5 (camadas inferiores), não são explotadas. O objetivo deste trabalho foi realizar um detalhamento das camadas inferiores, superiores e Banco Louco do depósito, utilizando como metodologia a aplicação dos conceitos de sedimentologia e estratigrafia de sequências; petrologia do carvão (descrição dos litotipos, análise da reflectância da vitrinita e análise de macerais) e análises químicas (imediatas, elementares, poder calorífico e difração de raios X). Foram identificados quatro sistemas deposicionais na área: leque aluvial, fluvial, laguna-barreira e marinho raso. A partir da base, a sucessão de litofácies compreende conglomerados matriz-suportado e arenitos grossos, sugerindo um ambiente típico para sistemas de leques aluviais e fluviais, com camadas de carvão pouco desenvolvidas (camadas inferiores). As principais camadas de carvão (espessas e contínuas) ocorrem no subambiente lagunar, no final do Trato de Sistemas Transgressivo da seqüência 2. As camadas superiores desenvolvem-se no Trato de Sistemas de Nível Alto e Trato de Sistemas de Nível Baixo, sendo tipicamente finas e descontinuas. Em seguida ocorrem sedimentos marinhos no topo da seção (Formação Palermo), sobrepostos à sucessão portadora de carvão. Os resultados das reflectâncias da vitrinita das camadas analisadas indicam um rank de carvão sub-bituminoso C (Rrandom= 0,36% - 0,47%), com evidências de alguns valores anômalos baixos relacionados ao alto conteúdo de matéria mineral. A análise dos litotipos determinou o litotipo fosco (durênio) predominante. A composição dos macerais é altamente variável, com algumas camadas extremamente ricas em macerais do grupo da inertinita (fusinita, semifusinita, inertodetrinita). A petrologia juntamente com a estratigrafia de seqüências mostra que as características do carvão são controladas pelo ambiente deposicional. Os resultados da análise elementar apresentam teores médios em peso das amostras de 28,3% para o carbono, 2,8% para o hidrogênio, 0,6% para o nitrogênio, 1,9% para o enxofre total e 20,3% para o oxigênio. A matéria volátil apresenta em média 43,6% em peso (d.a.f.) classificando as camadas de carvão como sub-bituminoso A. O poder calorífico calculado em uma base seca e livre de cinzas (d.a.f.) obteve valor médio de 5588 cal/g, classificando as amostras como sub-bituminoso B. Através da difração de raios X a mineralogia é constituída principalmente por quartzo, caolinita e ilita. As camadas de carvão analisadas são ricas em cinzas, utilizando os critérios do International Classification of in-Seam Coals (1998), a maioria das camadas é classificada como carvões de categoria muito inferior, entretanto, as camadas S4, I1, I4 e I5 são classificadas como rochas carbonosas (>50% em peso de cinza). Conforme dados da CRM, a usina termelétrica Presidente Médici pode operar com até 53% % em peso de cinzas e 2,0 de enxofre total. Assim sendo, as camadas S3, S6, S7, S8, S9, BL, I3 e I4 atenderiam as exigências de teor de cinzas e enxofre total máximo e exigido pela termelétrica. / The Candiota Coalfield, RS, is the largest coal deposit in the country, with coal seams developed in the Permian age the Rio Bonito Formation. Currently two seams are mined, called "Seam Candiota Superior" and "Seam Candiota Inferior". The other seams, S1-S9 (upper seams) and I1-I5 (lower seams) have not being mined so far. The aim of the present study was a characterization of the lower and upper seams of the deposit using methods of sequence stratigraphy and sedimentology, coal petrology (coal lithotypes, vitrinite reflectance, maceral analyses), and chemical characterization (proximate analysis, ultimate analysis, calorific value determination and x-ray diffraction). Sedimentological analyses identified four depositional systems in the area: alluvial fan, fluvial, lagoon-barrier and shallow marine. From the base, the succession of lithofacies comprises matrix-supported conglomerates and coarse grained sandstones, suggesting a typical environment for systems dominated by alluvial fans and river, with poorly developed coal seams (lower seams). The main coal seams (continuous, thick) occur in a lagoon-type subenvironment at the final stage of a transgressive systems tract of sequence 2. The upper seams developed in a Highstand Systems Tract and Lowstand Systems Tract, and are typically thin and discontinuous. Marine sediments occur at the top of the section (Palermo Formation), overlapping the coal-bearing strata. The results of the vitrinite reflectance measurements of the coal seams indicate a rank of sub-bituminous C (Rrandom = 0.36 - 0.47%), with evidence of some anomalous low values related to the high content of mineral matter. The dominant lithotype in the coal seams is durain. The maceral composition is highly variable, with some seams extremely rich in the maceral group inertinita (fusinite, semifusinite, inertodetrinite). The petrology along with the sequence stratigraphic interpretation show that the characteristics of the coal seams are controlled by depositional environment. Results from elemental analysis show that the average content (wt.%) were: 28.3% carbon, 2.8 % hydrogen, 0.6% for nitrogen, 1.9% for total sulfur and 20.3% for oxygen. The average volatile matter content obtained from proximate analyses is 43.6 wt% (daf), classifying the seams as sub-bituminous A. The average calorific value calculated on an dry, ash-free basis (daf) is 5588 cal /g, classifying the samples as sub-bituminous B. Based on results from x-ray diffraction the mineralogy consists mainly of quartz, kaolinite and illite. The coal seams are rich in ashes, ranging from 32,0 to 62,3 wt%, with most seams according to the International Classification System ranked as very low quality coals. Seams such as S4, I1, I4 and I5 are classified as carbonaceous rocks (> 50 wt.% ash). According to data from CRM, the President Medici power plant in Candiota can operate with coal containing of up to 53% wt% ash and 2,0 wt% total sulfur. Thus, coal seams S3, S6, S7, S8, S9, BL, I3 and I4 meet the requirements of maximum ash and total sulphur contents for combustion in the power plant.