An integrated study of coal geology and potential environmental impact assessment at Mchenga Coal Mine in Livingstonia Coalfield in Malawi
- Authors: Maneya, George Jameson
- Date: 2012
- Subjects: Coal -- Geology -- Malawi , Coal mines and mining -- Malawi , Coal mines and mining -- Environmental aspects -- Malawi , Environmental degradation -- Malawi
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11518 , http://hdl.handle.net/10353/480 , Coal -- Geology -- Malawi , Coal mines and mining -- Malawi , Coal mines and mining -- Environmental aspects -- Malawi , Environmental degradation -- Malawi
- Description: This study was carried out on the main coal-producing and the extensively block-faulted area of Mchenga Coal Mine, southeast of the 90 km2 intracratonic Livingstonia Coalfield in the north of Malawi. It was initiated against the background of indistinct information on coal geology, shortage of energy and potential environmental threats due to mine activities. The study aimed at integrating investigations of characterization of the lithostratigraphy, coal seam correlation, coal quality determination, examination of the mineralogy and geochemistry of coal and hosts rocks, assessment of water quality and providing information for mining and potential environmental and water quality impact assessment in the study area. The methodologies used in this study include literature review, field visits, mapping, sites selection and characterization, borehole logging, geochemical analyses, data processing and interpretation. The geochemical analyses include proximity analysis of coal quality, microscopy and X-ray Diffraction for mineralogy and petrology, X-ray Fluorescence (XRF) for rock geochemistry and Atomic Absorption Spectrometry for determination water geochemistry. The results have shown that a) The Coal Measures comprises of four to six coal seams in different localities, and the occurrence is flat and gently dipping southeast and are correlated. Thicknesses of the coal seams vary from 0.10m to 3.0m with some notable lateral and horizontal variations. Thick and workable seams occupy the lower portion of the Coal Measures and are exposed along the North Rumphi River bank; b) Coal quality belongs to sub-bituminous ‘A’ to ‘C’ on ASTM classification (1991), being characterised by low moisture content (0.8 to 1.3 wt percent) and sulphur content (0.49 to 0.85 wt percent), high ash content (9.0 to 17 wt percent) and volatile matter (24 to 32.9 wt percent), fixed carbon (53.6 to 62.6 wt percent), calorific value (7,015 to 7,670 kcal/kg); c) Mineral matters constitute approximately 9.55 to 38.34 wt percent of the coal samples, predominantly clays (interstratified illite/smectite and kaolinite) with varying proportions of quartz, mica and feldspars, as well as minor calcite and pyrite and their geochemistry, being characterised by enrichment of SiO2 from 5.37 to 20.56 wt percent, Al2O3 (2.63 to 11.21 wt percent) and K2O (0.32 to 3.65 wt percent) with trace concentrations of CaO (0.04 to 0.41 wt. percent), MgO (0.08 to 0.65 wt percent) and P2O5 (0.018 to 0.037 wt percent) and Na2O concentration notably below 0.01 wt percent; d) Calcite and pyrite constitute minor concentration in both sandstones and shales; e) Water quality in the area is characterised as two groups of acidic (pH 3.3-6.4) and near-neutral to slightly alkaline (pH 6.9-7.3) and low pH, high TDS, SO42- and EC are noted at the coal crusher plant which points out to high leaching of trace elements such as Pb and Fe. Na++K+ are dominant in upper sections of North Rumphi and Mhlepa Rivers. Ca2+ cations are dominant at crusher plant, underground mine and lower section of Mhlepa; f) Based on the geochemistry analysis, Na and trace elements such as Ti, V, Mn, Fe, Zn, Rb, Sr and Zr from coal and host rocks have the ability to contribute significantly to deterioration in the ground and surface water quality in the study area. It can be concluded that the coals of the Livingstonia Coalfield belong to Gondwana group deposited in sub-basin with multiple seams embedded in sandstone and shale host rocks.
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- Authors: Maneya, George Jameson
- Date: 2012
- Subjects: Coal -- Geology -- Malawi , Coal mines and mining -- Malawi , Coal mines and mining -- Environmental aspects -- Malawi , Environmental degradation -- Malawi
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11518 , http://hdl.handle.net/10353/480 , Coal -- Geology -- Malawi , Coal mines and mining -- Malawi , Coal mines and mining -- Environmental aspects -- Malawi , Environmental degradation -- Malawi
- Description: This study was carried out on the main coal-producing and the extensively block-faulted area of Mchenga Coal Mine, southeast of the 90 km2 intracratonic Livingstonia Coalfield in the north of Malawi. It was initiated against the background of indistinct information on coal geology, shortage of energy and potential environmental threats due to mine activities. The study aimed at integrating investigations of characterization of the lithostratigraphy, coal seam correlation, coal quality determination, examination of the mineralogy and geochemistry of coal and hosts rocks, assessment of water quality and providing information for mining and potential environmental and water quality impact assessment in the study area. The methodologies used in this study include literature review, field visits, mapping, sites selection and characterization, borehole logging, geochemical analyses, data processing and interpretation. The geochemical analyses include proximity analysis of coal quality, microscopy and X-ray Diffraction for mineralogy and petrology, X-ray Fluorescence (XRF) for rock geochemistry and Atomic Absorption Spectrometry for determination water geochemistry. The results have shown that a) The Coal Measures comprises of four to six coal seams in different localities, and the occurrence is flat and gently dipping southeast and are correlated. Thicknesses of the coal seams vary from 0.10m to 3.0m with some notable lateral and horizontal variations. Thick and workable seams occupy the lower portion of the Coal Measures and are exposed along the North Rumphi River bank; b) Coal quality belongs to sub-bituminous ‘A’ to ‘C’ on ASTM classification (1991), being characterised by low moisture content (0.8 to 1.3 wt percent) and sulphur content (0.49 to 0.85 wt percent), high ash content (9.0 to 17 wt percent) and volatile matter (24 to 32.9 wt percent), fixed carbon (53.6 to 62.6 wt percent), calorific value (7,015 to 7,670 kcal/kg); c) Mineral matters constitute approximately 9.55 to 38.34 wt percent of the coal samples, predominantly clays (interstratified illite/smectite and kaolinite) with varying proportions of quartz, mica and feldspars, as well as minor calcite and pyrite and their geochemistry, being characterised by enrichment of SiO2 from 5.37 to 20.56 wt percent, Al2O3 (2.63 to 11.21 wt percent) and K2O (0.32 to 3.65 wt percent) with trace concentrations of CaO (0.04 to 0.41 wt. percent), MgO (0.08 to 0.65 wt percent) and P2O5 (0.018 to 0.037 wt percent) and Na2O concentration notably below 0.01 wt percent; d) Calcite and pyrite constitute minor concentration in both sandstones and shales; e) Water quality in the area is characterised as two groups of acidic (pH 3.3-6.4) and near-neutral to slightly alkaline (pH 6.9-7.3) and low pH, high TDS, SO42- and EC are noted at the coal crusher plant which points out to high leaching of trace elements such as Pb and Fe. Na++K+ are dominant in upper sections of North Rumphi and Mhlepa Rivers. Ca2+ cations are dominant at crusher plant, underground mine and lower section of Mhlepa; f) Based on the geochemistry analysis, Na and trace elements such as Ti, V, Mn, Fe, Zn, Rb, Sr and Zr from coal and host rocks have the ability to contribute significantly to deterioration in the ground and surface water quality in the study area. It can be concluded that the coals of the Livingstonia Coalfield belong to Gondwana group deposited in sub-basin with multiple seams embedded in sandstone and shale host rocks.
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Lithostratigraphic correlation, mineralogy and geochemistry of the lower manganese orebody at the Kalagadi Manganese Mine in the Northern Cape Province of South Africa
- Authors: Rasmeni, Sonwabile
- Date: 2012
- Subjects: Manganese mines and mining -- South Africa , Manganese ores -- Geology -- South Africa , Mineralogy -- South Africa , Geochemistry -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11526 , http://hdl.handle.net/10353/d1016155 , Manganese mines and mining -- South Africa , Manganese ores -- Geology -- South Africa , Mineralogy -- South Africa , Geochemistry -- South Africa
- Description: The Kalagadi Manganese mine in the Kuruman area of the Northern Cape Province of South Africa contains reserves of Mn ore in excess of 100Mt. Mineralization in the mine lease area is restricted within the Hotazel Formation of the Voȅlwater Subgroup, belonging to the Postmasburg Group, the upper subdivision of the Transvaal Supergroup. Surface topography is characterized by flat lying, undulation with minimal faulting and the ore are slightly metarmophosed. This study investigates the general geology of the mine, lithostratigraphic subdivision and correlation of the economic Lower Manganese Orebody (LMO) of the Kalagadi Manganese Mine in order to guide mining plan and operations once the mine is fully commissioned. At the commencement of this study, Kalagadi Manganese mine was a project under exploration with no specific geology of the mine lease area and no lithostratigraphic subdivision. The study also aimed determining the extent of lithostratigraphic correlation between the LMO economic orebodies of the Kalagadi Manganese mine with that of underground Gloria and open-pit Mamatwan mines. Four methods including petrographic microscope, Scanning electron Microscope (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses were applied mainly for the mineral identification, chemical composition and ore characterization of the Lower Manganese Orebody (LMO) at Kalagadi Manganese mine. The results of this study indicates the following: (1) Eleven textural distinct zones with economic zones restricted to the middle while the lower grade zones are confined to the top and bottom of the LMO; (2) The economic zones, comprising of Y, M, C and N subzones attain an average thickness of 10 m and are graded at an average of 40% Mn while the Mn/Fe ratio varies from 6 to 9; (3) The most economic zones are M and N subzones which are mostly characterized by oxidized ovoids and laminae, a characteristic applicable even to other zones of economic interest; (4) Braunite is the main mineral of the manganese ore and is often integrown with kutnahorite and other minerals (hematite, hausmannite, Mg-calcite, calcite, jacobsite, serpentine and garnet) which are present in variable amounts; (5) The Mg-rich calcite (Ca, Mg)CO3 is the second dominant manganese carbonate mineral and it corresponds to elevated MgO concentration and is often associated with marine environment. The occurrence of the Mgcalcite is not common in the manganese ore of this area except for the Mn-calcite, which was not determined by XRD analyses in this study; (6) MnO is the most abundant major oxide in the manganese ore while other major oxides present in decreasing order of abundance are CaO, SiO2, Fe2O3, and MgO. The oxides TiO2, Na2O, K2O, Al2O3, and Cr2O3 are depleted and are mostly 0.01wt% and 0.001wt% respectively while P2O5 concentrations are low ranging from 0.02wt% to 0.3wt%. The trace element concentrations of Ba, Zn and Sr in most borehole samples are slightly elevated ranging from 100ppm to 3.9% (36000pm) while Co, Cu, Ni, Y, As, Zr, V and La rarely exceed 50ppm. The enrichments of Cu, Zn, Ni, Co and V that are commonly associated with volcanogenic hydrothermal input in chemicals may reach up to 70ppm; (7) The mineralogical and geochemical characteristics of the manganese ore in the Kalagadi Manganese mine lease area are similar to that of Low-Grade Mamatwan-Type ore. The cyclicity (Banded Iron Formation ↔ Hematite lutite ↔ braunite lutite) and alternation of manganese and iron formation have been confirmed; and (8) The oxygen δ18O isotope values (18‰ to 22‰) indicate a slight influence of metamorphism of the manganese ore. No positive correlation exists between δ13C vs δ18O values and Mn vs δ13C values. Such observations indicate minimal action of organic carbon during manganese precipitation where the organic matter was oxidized and manganese content reduced. On the other hand, the manganese carbonates (CaO) are positively correlated with carbon isotope, this indicates diagenetic alteration and the involvement of biogenic carbonate during the formation of manganese carbonates. It is concluded that the lithostratigraphic subdivision at Kalagadi Manganese mine is best correlated physically, mineralogically and geochemically with that of Gloria mine operating in the Low Grade Mamatwan - Type ore while correlation with an open-pit Mamatwan mine is also valid.
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- Authors: Rasmeni, Sonwabile
- Date: 2012
- Subjects: Manganese mines and mining -- South Africa , Manganese ores -- Geology -- South Africa , Mineralogy -- South Africa , Geochemistry -- South Africa
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11526 , http://hdl.handle.net/10353/d1016155 , Manganese mines and mining -- South Africa , Manganese ores -- Geology -- South Africa , Mineralogy -- South Africa , Geochemistry -- South Africa
- Description: The Kalagadi Manganese mine in the Kuruman area of the Northern Cape Province of South Africa contains reserves of Mn ore in excess of 100Mt. Mineralization in the mine lease area is restricted within the Hotazel Formation of the Voȅlwater Subgroup, belonging to the Postmasburg Group, the upper subdivision of the Transvaal Supergroup. Surface topography is characterized by flat lying, undulation with minimal faulting and the ore are slightly metarmophosed. This study investigates the general geology of the mine, lithostratigraphic subdivision and correlation of the economic Lower Manganese Orebody (LMO) of the Kalagadi Manganese Mine in order to guide mining plan and operations once the mine is fully commissioned. At the commencement of this study, Kalagadi Manganese mine was a project under exploration with no specific geology of the mine lease area and no lithostratigraphic subdivision. The study also aimed determining the extent of lithostratigraphic correlation between the LMO economic orebodies of the Kalagadi Manganese mine with that of underground Gloria and open-pit Mamatwan mines. Four methods including petrographic microscope, Scanning electron Microscope (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF) analyses were applied mainly for the mineral identification, chemical composition and ore characterization of the Lower Manganese Orebody (LMO) at Kalagadi Manganese mine. The results of this study indicates the following: (1) Eleven textural distinct zones with economic zones restricted to the middle while the lower grade zones are confined to the top and bottom of the LMO; (2) The economic zones, comprising of Y, M, C and N subzones attain an average thickness of 10 m and are graded at an average of 40% Mn while the Mn/Fe ratio varies from 6 to 9; (3) The most economic zones are M and N subzones which are mostly characterized by oxidized ovoids and laminae, a characteristic applicable even to other zones of economic interest; (4) Braunite is the main mineral of the manganese ore and is often integrown with kutnahorite and other minerals (hematite, hausmannite, Mg-calcite, calcite, jacobsite, serpentine and garnet) which are present in variable amounts; (5) The Mg-rich calcite (Ca, Mg)CO3 is the second dominant manganese carbonate mineral and it corresponds to elevated MgO concentration and is often associated with marine environment. The occurrence of the Mgcalcite is not common in the manganese ore of this area except for the Mn-calcite, which was not determined by XRD analyses in this study; (6) MnO is the most abundant major oxide in the manganese ore while other major oxides present in decreasing order of abundance are CaO, SiO2, Fe2O3, and MgO. The oxides TiO2, Na2O, K2O, Al2O3, and Cr2O3 are depleted and are mostly 0.01wt% and 0.001wt% respectively while P2O5 concentrations are low ranging from 0.02wt% to 0.3wt%. The trace element concentrations of Ba, Zn and Sr in most borehole samples are slightly elevated ranging from 100ppm to 3.9% (36000pm) while Co, Cu, Ni, Y, As, Zr, V and La rarely exceed 50ppm. The enrichments of Cu, Zn, Ni, Co and V that are commonly associated with volcanogenic hydrothermal input in chemicals may reach up to 70ppm; (7) The mineralogical and geochemical characteristics of the manganese ore in the Kalagadi Manganese mine lease area are similar to that of Low-Grade Mamatwan-Type ore. The cyclicity (Banded Iron Formation ↔ Hematite lutite ↔ braunite lutite) and alternation of manganese and iron formation have been confirmed; and (8) The oxygen δ18O isotope values (18‰ to 22‰) indicate a slight influence of metamorphism of the manganese ore. No positive correlation exists between δ13C vs δ18O values and Mn vs δ13C values. Such observations indicate minimal action of organic carbon during manganese precipitation where the organic matter was oxidized and manganese content reduced. On the other hand, the manganese carbonates (CaO) are positively correlated with carbon isotope, this indicates diagenetic alteration and the involvement of biogenic carbonate during the formation of manganese carbonates. It is concluded that the lithostratigraphic subdivision at Kalagadi Manganese mine is best correlated physically, mineralogically and geochemically with that of Gloria mine operating in the Low Grade Mamatwan - Type ore while correlation with an open-pit Mamatwan mine is also valid.
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Sedimentary environments and provenance of the Balfour Formation (Beaufort Group) in the area between Bedford and Adelaide, Eastern Cape Province, South Africa
- Authors: Oghenekome, Monica Enifome
- Date: 2012
- Subjects: Geology -- South Africa -- Balfour , Sedimentary basins -- South Africa -- Eastern Cape , Sediments (Geology) -- South Africa -- Eastern Cape , Sedimentation analysis , Beaufort Group (South Africa)
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11524 , http://hdl.handle.net/10353/d1004354 , Geology -- South Africa -- Balfour , Sedimentary basins -- South Africa -- Eastern Cape , Sediments (Geology) -- South Africa -- Eastern Cape , Sedimentation analysis , Beaufort Group (South Africa)
- Description: The research examines the sedimentary environments and provenance of the Balfour Formation of the Beaufort Group (Karoo Supergroup) in the Eastern Cape Province, South Africa. This Formation occurs in the southeastern part of the Karoo Basin. It consists of sedimentary rocks, which are an alternating siltstone, shale and mudstone succession with subordinate interbedded sandstone and subsequently intruded by Karoo dolerite in the form of sills and dykes. ithostratigraphically, the Balfour Formation is subdivided into five units namely, from the base to the top, the Oudeberg, Daggaboersnek, Barberskrans, Elandsberg and Palingkloof Members. The Balfour Formation is overlain by the Katberg Formation. This study involved field investigations in the vicinity of the towns of Bedford and Adelaide with integrated stratigraphical, sedimentological and petrological studies. A geological map was constructed after field investigations. Lithofacies of the Balfour Formation that were studied are characterised by sandstone facies (Sh, Sm, St, Sr, Sp) and fine-grained sediments (Fl or Fsm) which reflect point-bar, cut-bank, channel and floodplain deposits. Lithologically, the Oudeberg Member consists of sandstone of which some units are internally massive alternating with thin laminated siltstone and mudstone. The Daggaboersnek Member is characterised by regular, generally non-lenticular, overall stratification, in the Barberkrans Member consists of sandstone lithosomes, while the Elandsberg Member is an argillaceous unit, similar to the Daggaboersnek Member. The Palingkloof Member is composed predominantly of red mudstone that can be used to distinguish the Balfour Formation from the overlying Katberg Formation, which consists predominantly of sandstone. The stratigraphic sequence displays two fining upward megacycles of sedimentary deposits with change in the sediment supply pattern from low-sinuosity to high-sinuosity river systems which reflect both braid and meandering deposits, respectively. Sedimentary structures in the sandstone units and the provenance of the Balfour Formation indicate that these deposits were produced by rivers flowing from the southeast with minor drift towards the northwest. According to the composition of the sediments and their sequence of deposition the Formation represents a fluvial environment. Mineralogical and grain size data from the sandstones of the various members of the Balfour Formation indicate the same source area of granitic, metamorphic and older sedimentary rocks and show no significant petrographic differences. The petrographic and geochemical investigations confirmed the sandstone to be feldspathic litharenite and ultralithofeldspathic sandstone. The palaeocurrent investigation indicates the main provenance to have been situated to the southeast of the Karoo basin. Heavy-mineral concentrations within the sandstones also give an indication that the source had a transitional arc plate tectonic setting.
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- Authors: Oghenekome, Monica Enifome
- Date: 2012
- Subjects: Geology -- South Africa -- Balfour , Sedimentary basins -- South Africa -- Eastern Cape , Sediments (Geology) -- South Africa -- Eastern Cape , Sedimentation analysis , Beaufort Group (South Africa)
- Language: English
- Type: Thesis , Masters , MSc (Geology)
- Identifier: vital:11524 , http://hdl.handle.net/10353/d1004354 , Geology -- South Africa -- Balfour , Sedimentary basins -- South Africa -- Eastern Cape , Sediments (Geology) -- South Africa -- Eastern Cape , Sedimentation analysis , Beaufort Group (South Africa)
- Description: The research examines the sedimentary environments and provenance of the Balfour Formation of the Beaufort Group (Karoo Supergroup) in the Eastern Cape Province, South Africa. This Formation occurs in the southeastern part of the Karoo Basin. It consists of sedimentary rocks, which are an alternating siltstone, shale and mudstone succession with subordinate interbedded sandstone and subsequently intruded by Karoo dolerite in the form of sills and dykes. ithostratigraphically, the Balfour Formation is subdivided into five units namely, from the base to the top, the Oudeberg, Daggaboersnek, Barberskrans, Elandsberg and Palingkloof Members. The Balfour Formation is overlain by the Katberg Formation. This study involved field investigations in the vicinity of the towns of Bedford and Adelaide with integrated stratigraphical, sedimentological and petrological studies. A geological map was constructed after field investigations. Lithofacies of the Balfour Formation that were studied are characterised by sandstone facies (Sh, Sm, St, Sr, Sp) and fine-grained sediments (Fl or Fsm) which reflect point-bar, cut-bank, channel and floodplain deposits. Lithologically, the Oudeberg Member consists of sandstone of which some units are internally massive alternating with thin laminated siltstone and mudstone. The Daggaboersnek Member is characterised by regular, generally non-lenticular, overall stratification, in the Barberkrans Member consists of sandstone lithosomes, while the Elandsberg Member is an argillaceous unit, similar to the Daggaboersnek Member. The Palingkloof Member is composed predominantly of red mudstone that can be used to distinguish the Balfour Formation from the overlying Katberg Formation, which consists predominantly of sandstone. The stratigraphic sequence displays two fining upward megacycles of sedimentary deposits with change in the sediment supply pattern from low-sinuosity to high-sinuosity river systems which reflect both braid and meandering deposits, respectively. Sedimentary structures in the sandstone units and the provenance of the Balfour Formation indicate that these deposits were produced by rivers flowing from the southeast with minor drift towards the northwest. According to the composition of the sediments and their sequence of deposition the Formation represents a fluvial environment. Mineralogical and grain size data from the sandstones of the various members of the Balfour Formation indicate the same source area of granitic, metamorphic and older sedimentary rocks and show no significant petrographic differences. The petrographic and geochemical investigations confirmed the sandstone to be feldspathic litharenite and ultralithofeldspathic sandstone. The palaeocurrent investigation indicates the main provenance to have been situated to the southeast of the Karoo basin. Heavy-mineral concentrations within the sandstones also give an indication that the source had a transitional arc plate tectonic setting.
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