The Lumwana Copper Prospect in Zambia
- Authors: McGregor, James Archibald
- Date: 1965
- Subjects: Copper -- Zambia , Copper ores -- Zambia -- Analysis , Copper mines and mining -- Zambia , Mineralogy -- Zambia , Geology, Economic -- Zambia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5072 , http://hdl.handle.net/10962/d1013507
- Description: The Lumwana copper orebody is situated 170 miles west of the Copperbelt. It is stratiform and occurs in schists regarded as part of the Katanga System older than the lower-most Copperbelt quartzite. The discovery of copper at the Lumwana Prospect was a text book example of the success of the R.S.T. Mines Services Limited prospecting techniques. These include partial geochemical analyses of soil and drainage samples, pitting, drilling and radiometric, self potential, magnetic, resistivity and induced polarization methods of geophysical exploration. The copper-bearing formations at the Lumwana Prospect occur in the inverted limb of a great recumbent fold within the Mombezhi Dome. Three periods of folding are recognized from the study of regional foliations and lineation, and the attitude of fold elements in individual folds. Each period of folding is regarded as a major pulse in the Lufilian Orogeny. The first-formed folds are isoclinal and have axial planes which strike at 160°, and dip southwest at 15°; the plunge is 11° in a direction 212° . The formation of first folds was accompanied by thrust faulting and the development of nappe structures including the great Lumwana recumbent fold. The second folds have axial planes which strike at 170° and dip west at 44°, the plunge is 12° in a direction of 192°, and the folds tend to be overturned. The third folds cut across the earlier folds at variable angles, they are overturned to the north and have axial planes which dip gently to the south. The formation of third folds was such that northward-acting stress was rotated from southeast to southwest, and relaxation of this stress resulted in the development in competent strata of joints which strike at 120° and dip steeply. At the Lumwana Prospect the northward-acting Lufilian stress is thought to have been resolved into eastward acting stress during first and second folding as a result of compression near the centre of the Lufilian Arc. The third folds are the normal Lufilian folds sub-parallel to the Lufilian Arc. Normal faulting and intrusion of gabbro along planes of these faults and the earlier thrust faults eccurred in a post-Lufilian tensional phase. In recent times warping of the formations at Lumwana has occurred on east-west axes. Statistical examination of chemical data on fifty-four composite samples of mineralized rock from drill-holes reveals that the distribution of copper, iron and sulphur is related to that of potash and soda. These relationships can be explained on sedimentological grounds since the examination of the distribution of soda and potash in these and other horizons yields no evidence of metasomatism in the mineralized horizon. Intrusive into the mineralized schists, though not found in the ore, are thin amphibolites and a large serpentinite which contains relict olivine and bronzite. This is the first recorded occurrence of ultrabasic rocks in the Lower Roan Group of the Katanga System in this part of Zambia. Study of all formations at the Lumwana Prospect reveals that they have been metamorphosed in the epidote-amphibolite facies of regional metamorphism. Mineral assemblages indicative of the amphibolite facies are found in sheared rocks, and metamorphism in competent parts of the Upper Roan-Mwashia has been confined to the greenschist facies. Temperatures of metamorphism are estimated to have been between 250° and 280°C, and pressures are likely to have exceeded 6 kilobars. Evidence of metasomatism, absent in the Lower Roan, is found in the examination of the Upper Roan-Mwashia formations. Metasomatism includes scapolitization and albitization and is related to the intrusion of gabbro into these sediments, but does not necessarily involve exogenous material. The sulphide minerals identified are bornite, chalcocite, digenite, covellite, chalcopyrite, cubanite, valleriite, carrollite, pyrite and pyrrhotite. Intergrowths of these minerals have resulted from metamorphism at temperatures slightly in excess of 235°C. The copper sulphides are distributed zonally in the orebody with chalcocite- bornite ore where the mineralized schist is thin, and chalcopyrite- cubanite-pyrite ore where it is thick. Vertically the body contains horizons with sulphides relatively rich in copper at the top and bottom, and an intermediate zone with sulphides leaner in copper. This zonal distribution is considered to be evidence for syngenetic deposition of copper during successive cycles of transgression and regression. Ore genesis at Lumwana is closely related to genesis of the Copperbelt and Katanga orebodies. The Zambia-Katanga province is considered to have been enriched in copper epigenetically prior to the formation of the present-day orebodies. Reworking of these cupriferous rocks and some early-formed syngenetic deposits of which Lumwana is one, is considered to have played a major role in producing the present-day copper orebodies.
- Full Text:
- Date Issued: 1965
- Authors: McGregor, James Archibald
- Date: 1965
- Subjects: Copper -- Zambia , Copper ores -- Zambia -- Analysis , Copper mines and mining -- Zambia , Mineralogy -- Zambia , Geology, Economic -- Zambia
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5072 , http://hdl.handle.net/10962/d1013507
- Description: The Lumwana copper orebody is situated 170 miles west of the Copperbelt. It is stratiform and occurs in schists regarded as part of the Katanga System older than the lower-most Copperbelt quartzite. The discovery of copper at the Lumwana Prospect was a text book example of the success of the R.S.T. Mines Services Limited prospecting techniques. These include partial geochemical analyses of soil and drainage samples, pitting, drilling and radiometric, self potential, magnetic, resistivity and induced polarization methods of geophysical exploration. The copper-bearing formations at the Lumwana Prospect occur in the inverted limb of a great recumbent fold within the Mombezhi Dome. Three periods of folding are recognized from the study of regional foliations and lineation, and the attitude of fold elements in individual folds. Each period of folding is regarded as a major pulse in the Lufilian Orogeny. The first-formed folds are isoclinal and have axial planes which strike at 160°, and dip southwest at 15°; the plunge is 11° in a direction 212° . The formation of first folds was accompanied by thrust faulting and the development of nappe structures including the great Lumwana recumbent fold. The second folds have axial planes which strike at 170° and dip west at 44°, the plunge is 12° in a direction of 192°, and the folds tend to be overturned. The third folds cut across the earlier folds at variable angles, they are overturned to the north and have axial planes which dip gently to the south. The formation of third folds was such that northward-acting stress was rotated from southeast to southwest, and relaxation of this stress resulted in the development in competent strata of joints which strike at 120° and dip steeply. At the Lumwana Prospect the northward-acting Lufilian stress is thought to have been resolved into eastward acting stress during first and second folding as a result of compression near the centre of the Lufilian Arc. The third folds are the normal Lufilian folds sub-parallel to the Lufilian Arc. Normal faulting and intrusion of gabbro along planes of these faults and the earlier thrust faults eccurred in a post-Lufilian tensional phase. In recent times warping of the formations at Lumwana has occurred on east-west axes. Statistical examination of chemical data on fifty-four composite samples of mineralized rock from drill-holes reveals that the distribution of copper, iron and sulphur is related to that of potash and soda. These relationships can be explained on sedimentological grounds since the examination of the distribution of soda and potash in these and other horizons yields no evidence of metasomatism in the mineralized horizon. Intrusive into the mineralized schists, though not found in the ore, are thin amphibolites and a large serpentinite which contains relict olivine and bronzite. This is the first recorded occurrence of ultrabasic rocks in the Lower Roan Group of the Katanga System in this part of Zambia. Study of all formations at the Lumwana Prospect reveals that they have been metamorphosed in the epidote-amphibolite facies of regional metamorphism. Mineral assemblages indicative of the amphibolite facies are found in sheared rocks, and metamorphism in competent parts of the Upper Roan-Mwashia has been confined to the greenschist facies. Temperatures of metamorphism are estimated to have been between 250° and 280°C, and pressures are likely to have exceeded 6 kilobars. Evidence of metasomatism, absent in the Lower Roan, is found in the examination of the Upper Roan-Mwashia formations. Metasomatism includes scapolitization and albitization and is related to the intrusion of gabbro into these sediments, but does not necessarily involve exogenous material. The sulphide minerals identified are bornite, chalcocite, digenite, covellite, chalcopyrite, cubanite, valleriite, carrollite, pyrite and pyrrhotite. Intergrowths of these minerals have resulted from metamorphism at temperatures slightly in excess of 235°C. The copper sulphides are distributed zonally in the orebody with chalcocite- bornite ore where the mineralized schist is thin, and chalcopyrite- cubanite-pyrite ore where it is thick. Vertically the body contains horizons with sulphides relatively rich in copper at the top and bottom, and an intermediate zone with sulphides leaner in copper. This zonal distribution is considered to be evidence for syngenetic deposition of copper during successive cycles of transgression and regression. Ore genesis at Lumwana is closely related to genesis of the Copperbelt and Katanga orebodies. The Zambia-Katanga province is considered to have been enriched in copper epigenetically prior to the formation of the present-day orebodies. Reworking of these cupriferous rocks and some early-formed syngenetic deposits of which Lumwana is one, is considered to have played a major role in producing the present-day copper orebodies.
- Full Text:
- Date Issued: 1965
The relationship between acquired resistance and transmission of Schistosoma Weinland, 1858, in man and its influences on the prevalence of S Capense (Harley, 1864) and S Mansoni Sambon, 1907, in Southern Rhodesia
- Authors: Clarke, H V de V
- Date: 1965
- Subjects: Platyhelminthes , Schistosoma , Schistosomiasis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5842 , http://hdl.handle.net/10962/d1010500 , Platyhelminthes , Schistosoma , Schistosomiasis
- Description: Bilharziasis ranks with Tuberculosis and Malaria as the three most important endemic diseases of man in Rhodesia. The prominence given to bilharziasis in the endemic diseases pattern arises from its high prevalence, particularly in the African population. It is probable that bilharziasis was endemic in the country even prior to the arrival in the conntry of the European settlers in 1890, but it was not until Orpen (1915) described the results of a small survey that local infections were proven. He reported 182 (31 percent) urinary infections in 592 African prisoners examined in the Salisbury gaol. In the ensuing 15 years there was only scanty evidence of the prevalence of the disease. However, in the decade 1931 to 1940 the Annual Public Health Reports of Southern Rhodesia indicated increasing prevalence, and this stimulated interest in the problem and led to the establishment in 1939 of a specialised laboratory to study the parasites causing the disease. The unpublished records of this laboratory indicate that in more recent years the disease has increased not only in prevalence but also in its intensity in infected individuals. Surveys show that the urinary form of the disease is more widespread than the intestinal form. Both forms are becoming more prevalent but the rapid increase of the latter, considered by most authorities to be the more severe, indicates that a greater importance must be accorded to it in the future. Introduction, p. 1.
- Full Text:
- Date Issued: 1965
- Authors: Clarke, H V de V
- Date: 1965
- Subjects: Platyhelminthes , Schistosoma , Schistosomiasis
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:5842 , http://hdl.handle.net/10962/d1010500 , Platyhelminthes , Schistosoma , Schistosomiasis
- Description: Bilharziasis ranks with Tuberculosis and Malaria as the three most important endemic diseases of man in Rhodesia. The prominence given to bilharziasis in the endemic diseases pattern arises from its high prevalence, particularly in the African population. It is probable that bilharziasis was endemic in the country even prior to the arrival in the conntry of the European settlers in 1890, but it was not until Orpen (1915) described the results of a small survey that local infections were proven. He reported 182 (31 percent) urinary infections in 592 African prisoners examined in the Salisbury gaol. In the ensuing 15 years there was only scanty evidence of the prevalence of the disease. However, in the decade 1931 to 1940 the Annual Public Health Reports of Southern Rhodesia indicated increasing prevalence, and this stimulated interest in the problem and led to the establishment in 1939 of a specialised laboratory to study the parasites causing the disease. The unpublished records of this laboratory indicate that in more recent years the disease has increased not only in prevalence but also in its intensity in infected individuals. Surveys show that the urinary form of the disease is more widespread than the intestinal form. Both forms are becoming more prevalent but the rapid increase of the latter, considered by most authorities to be the more severe, indicates that a greater importance must be accorded to it in the future. Introduction, p. 1.
- Full Text:
- Date Issued: 1965
Xhosa-English pronunciation in the south-east Cape
- Authors: Hundleby, C E
- Date: 1965
- Subjects: Xhosa language -- Pronunciation by foreign speakers English language -- Pronunciation by foreign speakers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2303 , http://hdl.handle.net/10962/d1012467
- Description: The thesis mainly concerns itself with an analysis of the present day pronunciation of Xhosa-English. The isolation and identification of the segmental phonemes and the phonemes of stress, intonation and transition form the core of the work. The author has attempted to give continuity by introducing a subsidiary theme, the Lado hypothesis as stated on page 1. In conformity with the the methodology imposed by the Lado formula, it was first necessary to establish two things: first, a standard background against which the characteristics of XEP could be compared, and secondly, to give briefly, but in sufficient detail for our purpose, the main phonological features of the mother tongue.
- Full Text:
- Date Issued: 1965
- Authors: Hundleby, C E
- Date: 1965
- Subjects: Xhosa language -- Pronunciation by foreign speakers English language -- Pronunciation by foreign speakers
- Language: English
- Type: Thesis , Doctoral , PhD
- Identifier: vital:2303 , http://hdl.handle.net/10962/d1012467
- Description: The thesis mainly concerns itself with an analysis of the present day pronunciation of Xhosa-English. The isolation and identification of the segmental phonemes and the phonemes of stress, intonation and transition form the core of the work. The author has attempted to give continuity by introducing a subsidiary theme, the Lado hypothesis as stated on page 1. In conformity with the the methodology imposed by the Lado formula, it was first necessary to establish two things: first, a standard background against which the characteristics of XEP could be compared, and secondly, to give briefly, but in sufficient detail for our purpose, the main phonological features of the mother tongue.
- Full Text:
- Date Issued: 1965
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