A comparison of the performance of three conceptual mathematical models of the rainfall-runoff process in the Mareetsane Catchment
- Authors: Stickells Peter S
- Date: 1979
- Subjects: Rain and rainfall Mathematical models South Africa Runoff
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4793 , http://hdl.handle.net/10962/d1001893
- Description: The objective of the thesis is to make a critical assessment of the performance of three relatively simple deterministic models of the rainfall-runoff process. The need to evaluate and compare deterministic models arises because of the large number of models which are available in the literature. A number of the available models would appear to be equally suitable for a given situation whereas many models are found to be valid only under the specific range of conditions for which they were developed. Therefore there is a need for guidelines to allow the most judicious selection of a model for a particular set of circumstances. The models used in the study will be tested in a semi-arid catchment to determine their applicability under ephemeral flow conditions
- Full Text:
- Date Issued: 1979
- Authors: Stickells Peter S
- Date: 1979
- Subjects: Rain and rainfall Mathematical models South Africa Runoff
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4793 , http://hdl.handle.net/10962/d1001893
- Description: The objective of the thesis is to make a critical assessment of the performance of three relatively simple deterministic models of the rainfall-runoff process. The need to evaluate and compare deterministic models arises because of the large number of models which are available in the literature. A number of the available models would appear to be equally suitable for a given situation whereas many models are found to be valid only under the specific range of conditions for which they were developed. Therefore there is a need for guidelines to allow the most judicious selection of a model for a particular set of circumstances. The models used in the study will be tested in a semi-arid catchment to determine their applicability under ephemeral flow conditions
- Full Text:
- Date Issued: 1979
A computer-controlled tracking system
- Authors: Oberem, Graham Edmund
- Date: 1979
- Subjects: Artificial satellites -- Tracking
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5437 , http://hdl.handle.net/10962/d1001990
- Description: A computer-controlled tracking system has been designed and constructed for the two metre antenna of the 22 GHz radio telescope at Rhodes University. The control system has been tested and its step response has been analysed with a view to response time optimization. Computer programs for tracking the sun and the moon have been written. Initial results of tracking the sun have revealed linearity and temperature stability problems. These problems have been investigated and suggestions have been made as to how they might be removed
- Full Text:
- Date Issued: 1979
- Authors: Oberem, Graham Edmund
- Date: 1979
- Subjects: Artificial satellites -- Tracking
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5437 , http://hdl.handle.net/10962/d1001990
- Description: A computer-controlled tracking system has been designed and constructed for the two metre antenna of the 22 GHz radio telescope at Rhodes University. The control system has been tested and its step response has been analysed with a view to response time optimization. Computer programs for tracking the sun and the moon have been written. Initial results of tracking the sun have revealed linearity and temperature stability problems. These problems have been investigated and suggestions have been made as to how they might be removed
- Full Text:
- Date Issued: 1979
A re-examination of the Carter solutions of Einstein's field equations
- Authors: Kun, A Ah
- Date: 1979
- Subjects: Einstein field equations Space and time General relativity (Physics)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5442 , http://hdl.handle.net/10962/d1001995
- Description: The study of geodesics in space-time is essential to a comprehensive understanding of the physics of the field. Global properties, e.g. the singularity structure and completeness of space-time, can be related to the geodesic properties, thus it is through the solutions of the geodesic equation of motion that many of the global properties of space-time can be obtained in an easily interpretable form. However, it is usually very difficult to integrate the geodesic equations for the particle motion in the presence of a gravitational field (Introduction, p. 1)
- Full Text:
- Date Issued: 1979
- Authors: Kun, A Ah
- Date: 1979
- Subjects: Einstein field equations Space and time General relativity (Physics)
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5442 , http://hdl.handle.net/10962/d1001995
- Description: The study of geodesics in space-time is essential to a comprehensive understanding of the physics of the field. Global properties, e.g. the singularity structure and completeness of space-time, can be related to the geodesic properties, thus it is through the solutions of the geodesic equation of motion that many of the global properties of space-time can be obtained in an easily interpretable form. However, it is usually very difficult to integrate the geodesic equations for the particle motion in the presence of a gravitational field (Introduction, p. 1)
- Full Text:
- Date Issued: 1979
A review of landscape development and erosion cycles in southern Africa
- Authors: Corbett, Dudley Harold
- Date: 1979
- Subjects: Landscape changes -- Africa, Southern Erosion -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4899 , http://hdl.handle.net/10962/d1001558
- Description: The study of landforms has, to a large extent been neglected by exploration geologists. This is surprising because field geology is intimately related with landforms of one type or another. An understanding of the geomorphological history of a particular area will assist in the appreciation of the surficial environment, the processes of weathering, soil formation and duricrust (calcrete , ferricrete silcrete) formation. This has direct application in planning and interpreting geochemical sampling programmes. In order to understand the evolution of landforms it is necessary to study slope development in some detail. Agents of erosion and denudation constantly at work, remove detritus from hillcrests down to the drainage lines which form the local base level from whence material is transported down to the sea. The system is one of dynamic equilibrium, and the concept of grade is important in understanding hillslope evolution. Thus Section (1) of this discussion deals with past and present theories of hillslope evolution. Very little work has been done recently on the geomorphology of Southern Africa and the presently accepted classification of land surfaces is based on the work of Prof. L.C. King (numerous publications). However, through the more recent work of De Swardt and Bennet (1974) on the geomorphology of Natal, it is apparent that the present system of landform classification in Southern Africa requires widespread revision. The relationship of erosion cycles in Southern Africa to the late Jurassic-early Cretaceous break-up of Gondwanaland has received insufficient attention in the past. Erosion cycles bear an intimate relationship to offshore Cretaceous and Tertiary-Recent sedimentation. Valuable information on these sediments has only recently become available as a result of offshore exploration for oil. The findings of De Swardt and Bennet (1974) are summarized in Section (2) and the present land surface classification of Southern Africa is reviewed. Finally, some suggestions on a new interpretation of land surfaces in Southern Africa are given.
- Full Text:
- Date Issued: 1979
- Authors: Corbett, Dudley Harold
- Date: 1979
- Subjects: Landscape changes -- Africa, Southern Erosion -- Africa, Southern
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4899 , http://hdl.handle.net/10962/d1001558
- Description: The study of landforms has, to a large extent been neglected by exploration geologists. This is surprising because field geology is intimately related with landforms of one type or another. An understanding of the geomorphological history of a particular area will assist in the appreciation of the surficial environment, the processes of weathering, soil formation and duricrust (calcrete , ferricrete silcrete) formation. This has direct application in planning and interpreting geochemical sampling programmes. In order to understand the evolution of landforms it is necessary to study slope development in some detail. Agents of erosion and denudation constantly at work, remove detritus from hillcrests down to the drainage lines which form the local base level from whence material is transported down to the sea. The system is one of dynamic equilibrium, and the concept of grade is important in understanding hillslope evolution. Thus Section (1) of this discussion deals with past and present theories of hillslope evolution. Very little work has been done recently on the geomorphology of Southern Africa and the presently accepted classification of land surfaces is based on the work of Prof. L.C. King (numerous publications). However, through the more recent work of De Swardt and Bennet (1974) on the geomorphology of Natal, it is apparent that the present system of landform classification in Southern Africa requires widespread revision. The relationship of erosion cycles in Southern Africa to the late Jurassic-early Cretaceous break-up of Gondwanaland has received insufficient attention in the past. Erosion cycles bear an intimate relationship to offshore Cretaceous and Tertiary-Recent sedimentation. Valuable information on these sediments has only recently become available as a result of offshore exploration for oil. The findings of De Swardt and Bennet (1974) are summarized in Section (2) and the present land surface classification of Southern Africa is reviewed. Finally, some suggestions on a new interpretation of land surfaces in Southern Africa are given.
- Full Text:
- Date Issued: 1979
A review of the economic geology of tungsten
- Authors: Bowles, Michael
- Date: 1979
- Subjects: Tungsten Geology, Economic
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4897 , http://hdl.handle.net/10962/d1001556
- Description: A description of the geochemistry of tungsten is given. The geochemical properties of tungsten have a strong influence on its mineralogy, distribution and abundance in crustal rocks and rock-forming minerals , and its migration/deposition within the ore-forming and supergene environments. The behaviour of tungsten during migration, from source to site of deposition, within the crust is discussed in some detail and environments considered favourable to the concentration of tungsten ore minerals are suggested. All major types of tungsten ore deposit are described with emphasis placed on those of greater economic importance. Characteristic features of each type of deposit are particularly emphasized in order to provide clear guidelines to exploration. Hydrothermal, pyrometasomatic and stratabound tungsten deposits present themselves, economically, as the most important exploration targets. The recently developed concept of syngenetic stratabound tungsten mineralisation is outlined. Exploration for deposits of this type should be aimed predominantly, but not exclusively, at volcano-sedimentary sequences of Lower Palaeozoic age, particularly within regions known to contain occurrences of Sb and Hg. Tungsten deposits commonly contain concentrations of one or more of the following metals: Sn, Sb, Bi, Mo, Au and Ag. The presence and possible extractive value of these metals, together with commonly associated metal impurities such as As, must always be taken into account in a feasibility study , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1979
- Authors: Bowles, Michael
- Date: 1979
- Subjects: Tungsten Geology, Economic
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4897 , http://hdl.handle.net/10962/d1001556
- Description: A description of the geochemistry of tungsten is given. The geochemical properties of tungsten have a strong influence on its mineralogy, distribution and abundance in crustal rocks and rock-forming minerals , and its migration/deposition within the ore-forming and supergene environments. The behaviour of tungsten during migration, from source to site of deposition, within the crust is discussed in some detail and environments considered favourable to the concentration of tungsten ore minerals are suggested. All major types of tungsten ore deposit are described with emphasis placed on those of greater economic importance. Characteristic features of each type of deposit are particularly emphasized in order to provide clear guidelines to exploration. Hydrothermal, pyrometasomatic and stratabound tungsten deposits present themselves, economically, as the most important exploration targets. The recently developed concept of syngenetic stratabound tungsten mineralisation is outlined. Exploration for deposits of this type should be aimed predominantly, but not exclusively, at volcano-sedimentary sequences of Lower Palaeozoic age, particularly within regions known to contain occurrences of Sb and Hg. Tungsten deposits commonly contain concentrations of one or more of the following metals: Sn, Sb, Bi, Mo, Au and Ag. The presence and possible extractive value of these metals, together with commonly associated metal impurities such as As, must always be taken into account in a feasibility study , Adobe Acrobat 9.53 Paper Capture Plug-in
- Full Text:
- Date Issued: 1979
Adreno-active substances and the pineal gland
- Authors: Midlane, Graham Wallace
- Date: 1979
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3738 , http://hdl.handle.net/10962/d1001530
- Description: The pineal gland, a biochemically very active neuroendocrine transducer which is innervated by the sympathetic nervous system, was used in vivo to evaluate the effect of different þ-adrenoceptor agonists and antagonists on pineal enzyme levels. Hydroxyindole-O-methyltransferase (HIOMT), an enzyme with a circadian activity and unknown control was not significantly affected by these drugs. The activity of serotonin N-acetyltransferase, another pineal enzyme with a greater amplitude of circadian rhythmicity and which is under noradrenergic neural control, the degree of blockade depending on the selectivity and affinity of the agent used. An attempt was also made to alter the oestrous cycle of the rat by dosing with þ-active substances. Only propranolol had any effect on the oestrous cycle. It was not possible to establish an absolute link between the alteration in pineal enzyme activity and an influence on the oestrous cycle. It was concluded that the pineal enzyme studies are useful pharmacological means for evaluating þ-active substances
- Full Text:
- Date Issued: 1979
- Authors: Midlane, Graham Wallace
- Date: 1979
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3738 , http://hdl.handle.net/10962/d1001530
- Description: The pineal gland, a biochemically very active neuroendocrine transducer which is innervated by the sympathetic nervous system, was used in vivo to evaluate the effect of different þ-adrenoceptor agonists and antagonists on pineal enzyme levels. Hydroxyindole-O-methyltransferase (HIOMT), an enzyme with a circadian activity and unknown control was not significantly affected by these drugs. The activity of serotonin N-acetyltransferase, another pineal enzyme with a greater amplitude of circadian rhythmicity and which is under noradrenergic neural control, the degree of blockade depending on the selectivity and affinity of the agent used. An attempt was also made to alter the oestrous cycle of the rat by dosing with þ-active substances. Only propranolol had any effect on the oestrous cycle. It was not possible to establish an absolute link between the alteration in pineal enzyme activity and an influence on the oestrous cycle. It was concluded that the pineal enzyme studies are useful pharmacological means for evaluating þ-active substances
- Full Text:
- Date Issued: 1979
An automatic programming system to generate payroll programs
- Fielding, Elizabeth Vera Catherine
- Authors: Fielding, Elizabeth Vera Catherine
- Date: 1979
- Subjects: Computer software -- Development , Programming (computers) , Software architecture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4695 , http://hdl.handle.net/10962/d1011829 , Computer software -- Development , Programming (computers) , Software architecture
- Description: The purpose of this project was to try to investigate one approach to the problem of automatically generating programs from some specification. Rather than following the approach which requires the user to define his problem using some formulation, it was decided to look at a class of problems that have similar solutions, but have many variations, and to try to design a system capable of obtaining user requirements and generating solutions tailored to these requirements. The aim was to design the system in such a way that it could be extended to cater for other classes of problems, so that eventually a system which could automatically generate program solutions for a range of problems might be developed. Intro. p. 1.
- Full Text:
- Date Issued: 1979
- Authors: Fielding, Elizabeth Vera Catherine
- Date: 1979
- Subjects: Computer software -- Development , Programming (computers) , Software architecture
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4695 , http://hdl.handle.net/10962/d1011829 , Computer software -- Development , Programming (computers) , Software architecture
- Description: The purpose of this project was to try to investigate one approach to the problem of automatically generating programs from some specification. Rather than following the approach which requires the user to define his problem using some formulation, it was decided to look at a class of problems that have similar solutions, but have many variations, and to try to design a system capable of obtaining user requirements and generating solutions tailored to these requirements. The aim was to design the system in such a way that it could be extended to cater for other classes of problems, so that eventually a system which could automatically generate program solutions for a range of problems might be developed. Intro. p. 1.
- Full Text:
- Date Issued: 1979
Aspects of the bioavailability of topical corticosteroid formulations
- Authors: Magnus, Ashley Denis
- Date: 1979
- Subjects: Adrenocortical hormones , Dermatopharmacology , Dermatologic agents , Transdermal medication
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3724 , http://hdl.handle.net/10962/d1001458
- Description: Two possible variables of the McKenzie/Stoughton blanching assay, namely amount applied to the test site and occlusion time have been investigated. Subsequently, two topical steroid preparations, Synalar cream (0,025% fluocinolone acetonide) and Betnovate cream (0,1% betamethasone 17- valerate) were extemporaneously diluted with five and six placebo bases respectively. Taking cognizance of the two possible variables, these diluted preparations were assessed in vivo using a modified version of the McKenzie/Stoughton blanching assay for blanching activity over a 14 month period. It was found that the base E45, which is slightly alkali, had the greatest effect on both preparations. In the case of betamethasone 17-valerate this base caused the conversion to the less active isomer, betamethasone 21-valerate whereas at the end of the 14 month test period it was found that the Synalar/E45 dilution contained no fluocinolone acetonide. Quantitative analysis of all the diluted preparations by high performance liquid chromatography using a reverse-phase system was performed. The data obtained from the systematic studies of the effects of varying concentrations and occlusion times were presented at the Eleventh National Congress of the South African Pharmacological Society
- Full Text:
- Date Issued: 1979
- Authors: Magnus, Ashley Denis
- Date: 1979
- Subjects: Adrenocortical hormones , Dermatopharmacology , Dermatologic agents , Transdermal medication
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:3724 , http://hdl.handle.net/10962/d1001458
- Description: Two possible variables of the McKenzie/Stoughton blanching assay, namely amount applied to the test site and occlusion time have been investigated. Subsequently, two topical steroid preparations, Synalar cream (0,025% fluocinolone acetonide) and Betnovate cream (0,1% betamethasone 17- valerate) were extemporaneously diluted with five and six placebo bases respectively. Taking cognizance of the two possible variables, these diluted preparations were assessed in vivo using a modified version of the McKenzie/Stoughton blanching assay for blanching activity over a 14 month period. It was found that the base E45, which is slightly alkali, had the greatest effect on both preparations. In the case of betamethasone 17-valerate this base caused the conversion to the less active isomer, betamethasone 21-valerate whereas at the end of the 14 month test period it was found that the Synalar/E45 dilution contained no fluocinolone acetonide. Quantitative analysis of all the diluted preparations by high performance liquid chromatography using a reverse-phase system was performed. The data obtained from the systematic studies of the effects of varying concentrations and occlusion times were presented at the Eleventh National Congress of the South African Pharmacological Society
- Full Text:
- Date Issued: 1979
Gold mineralization in archaean cherts and iron-formations a review of the economic geology
- Authors: Bellamy, R E S
- Date: 1979
- Subjects: Gold ores -- Geology -- South Africa , Gold mines and mining -- South Africa , Greenstone belts -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4968 , http://hdl.handle.net/10962/d1005580 , Gold ores -- Geology -- South Africa , Gold mines and mining -- South Africa , Greenstone belts -- South Africa
- Description: The distribution of gold in igneous rocks and minerals is described and discussed. Not all the gold in igneous rocks is contained within early formed crystal lattices. Evidence that gold can be associated with late stage crystallizing phases is described. It is concluded that some of the gold in hydrothermal and volcanogenic deposits may have come from a primary magmatic source rather than having been leached from solid country rock. Gold is probably transported as chloride complexes at temperatures greater than about 300°C. At lower temperatures it is probably transported with other metals as sulphide and thio-sulphide complexes. The precipitation of gold from the transporting medium is brought about by changes in the physico-chemical conditions within that medium. Decrease in pressure is probably not a major cause of precipitation in volcanogenic environments. The geology of volcanogenic iron-formations is described and discussed, relative to the development of greenstone belts. Oxide facies iron-formations were formed in shallow oxidizing environments. They are associated with volcanogenic and clastic sediments. Sulphide facies iron-formations were precipitated in the deeper parts of geosynclinal structures. They are associated with mafic and ultramafic rocks similar to modern oceanic volcanic assemblages. Carbonate facies iron-formations were deposited in the regions between oxide facies and sulphide facies. Other banded iron-formations are found associated with base metal massive sulphide deposits related to arctype volcanic centres. These deposits are found in the regions where carbonate facies iron-formations were formed. Exploration for and exploitation of gold deposits in Archaean iron-formations are discussed. Geochemical exploration programmes are aided by the association of gold with trace amounts of base metals. Geophysical exploration methods that can be employed include magnetometer, I.P. and E.M. surveys. The metallurgical treatment of the ores should include "roasting" because a large proportion of the gold occurs as submicroscopic grains within sulphide mineral crystals.
- Full Text:
- Date Issued: 1979
- Authors: Bellamy, R E S
- Date: 1979
- Subjects: Gold ores -- Geology -- South Africa , Gold mines and mining -- South Africa , Greenstone belts -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4968 , http://hdl.handle.net/10962/d1005580 , Gold ores -- Geology -- South Africa , Gold mines and mining -- South Africa , Greenstone belts -- South Africa
- Description: The distribution of gold in igneous rocks and minerals is described and discussed. Not all the gold in igneous rocks is contained within early formed crystal lattices. Evidence that gold can be associated with late stage crystallizing phases is described. It is concluded that some of the gold in hydrothermal and volcanogenic deposits may have come from a primary magmatic source rather than having been leached from solid country rock. Gold is probably transported as chloride complexes at temperatures greater than about 300°C. At lower temperatures it is probably transported with other metals as sulphide and thio-sulphide complexes. The precipitation of gold from the transporting medium is brought about by changes in the physico-chemical conditions within that medium. Decrease in pressure is probably not a major cause of precipitation in volcanogenic environments. The geology of volcanogenic iron-formations is described and discussed, relative to the development of greenstone belts. Oxide facies iron-formations were formed in shallow oxidizing environments. They are associated with volcanogenic and clastic sediments. Sulphide facies iron-formations were precipitated in the deeper parts of geosynclinal structures. They are associated with mafic and ultramafic rocks similar to modern oceanic volcanic assemblages. Carbonate facies iron-formations were deposited in the regions between oxide facies and sulphide facies. Other banded iron-formations are found associated with base metal massive sulphide deposits related to arctype volcanic centres. These deposits are found in the regions where carbonate facies iron-formations were formed. Exploration for and exploitation of gold deposits in Archaean iron-formations are discussed. Geochemical exploration programmes are aided by the association of gold with trace amounts of base metals. Geophysical exploration methods that can be employed include magnetometer, I.P. and E.M. surveys. The metallurgical treatment of the ores should include "roasting" because a large proportion of the gold occurs as submicroscopic grains within sulphide mineral crystals.
- Full Text:
- Date Issued: 1979
Sedimentology of the Katberg sandstone in the Eastern Cape Province
- Authors: Stavrakis, Nicholas
- Date: 1979 , 2013-10-16
- Subjects: Sedimentology -- South Africa -- Eastern Cape , Geology, Stratigraphic -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5034 , http://hdl.handle.net/10962/d1007355 , Sedimentology -- South Africa -- Eastern Cape , Geology, Stratigraphic -- South Africa -- Eastern Cape
- Description: The Katberg Sandstone is an arenaceous formation occuring stratigraphically three querters of the way up in the Beaufort Group in the south-eastern part of the main Karoo basin. A sedimentological study was carried out on the Katberg Sandstone and adjacent formations, in a 2 000 km² area south of Queenstown. Stratigraphic sections were measured and lithofacies based on the style of Miall (1977) were established for the Katberg Sandstone, Balfour and Burgersdorp Formations. Stratigraphic relationships show that the Burgersdorp Formation in the study area, is the lateral (distal) equivalent of the Katberg Sandstone. The changeover from sandstone to predominantly shale lithology occurs roughly east-west between Cathcart and Whittlesea. Stream hydraulic theory is discussed and the sedimentary structures of the various lithofacies are explained in terms of this theory. An analysis was done of thirty-four palaeochannels, and their various ancient flow characteristics were derived via multiple regression equations and a FORTRAN computer program. A statistical analysis of bedform structures, showed that flat-bedding of the upper flow regime is the dominant sedimentary structure of the Katberg Sandstone. Trough cross-bedding originating in aqueous dunes and planar cross-bedding of transverse bars, are fairly well represented while ripples are virtually absent. The opposite applies to the Balfour Formation where lower flow regime structures, viz., ripple cross-lamination and trough cross-bedding predominate. There is an even spread of (upper) flat-bedding, trough cross-bedding and ripple cross-lamination in the Burgersdorp Formation. Detailed measurement of typical short sequences from sections of the three formations, and transition matrix analyses, showed the facies assemblages to be of three stream types: (i) Katberg type: similar to Platte type of Miall (1977). Sediments were deposited by swiftly flowing, low sinuosity, braided, ephemeral streams with a predominantly sand bedload. Each flow started with preconsolidated silt and mud (flakes), and movement of exogenetic pebble lags. Channel avulsion and deposition of mud drapes in higher topographic levels of the stream were common phenomena. (ii) Balfour type: characterised by lateral accretion point bar type sequences of high sinuosity streams, and vertical accretion floodplain deposits. Lower flow regime dune and ripple bedform structures overlying (upper) flat-beds indicate a loss of stream power with channel migration. (iii) Burgersdorp type: similar to Katberg type for sandstone units, also crevasse-splays onto thick subaerially exposed floodplain aggradation reddish shales. Conventional microscopy and SEM studies showed tremendous diagenetic effects mostly in the form of secondary quartz growth in the sandstones of the three formations. Electron microprobe analyses were done on titanomagnetite grains from heavy mineral layers of the Katberg Sandstone, so that thermometric predictions could be made on provenance rocks. Palaeocurrents of the Katberg Sandstone are mostly Rank 4 and 5 types (Miall, 1974), i.e., they were generated within bars with not much change in stream orientation. Burgersdorp and Balfour formation palaeocurrents are Rank 1 - 3 types. In the case of the former this is owing to directional changes in channels as a result of frequent crevasse-splays, and in the case of the latter owing to differences in orientation between entire tracts of highly sinuous palaeostreams. Palaeocurrent directions in the Katberg Sandstone indicate a southeasterly provenance which accords with the findings of other Beaufort Group workers. Bed relief index calculations (Smith, 1970), made on Katberg rocks, considered together with the abundance of planar cross-bedding (of transverse bars) and apparent absence of longitudinal bars, testify to the deposition of the Katberg Sandstone in the distal parts of the braided stream environment. The Beaufort sediments of the study area have the sedimentological characteristics of a molasse sequence, but a different implied tectonogenesis. During Balfour sedimentation the equilibrium base was being raised very slowly at the source and complete fluvial sequences were deposited under a humid temperate climate, on a slowly subsiding plain. During Katberg/Burgersdorp times, source area tectonism was pronounced but interrupted and incomplete sequences were deposited under an arid climate. Provenance rocks for the formations studied included biotite mesoperthitic granite, granulite, charnockite, granite porphyry, granophyre, metaquartzite, greenschist and possibly diorite, epidosit e and alkaline volcanic rocks. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1979
- Authors: Stavrakis, Nicholas
- Date: 1979 , 2013-10-16
- Subjects: Sedimentology -- South Africa -- Eastern Cape , Geology, Stratigraphic -- South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5034 , http://hdl.handle.net/10962/d1007355 , Sedimentology -- South Africa -- Eastern Cape , Geology, Stratigraphic -- South Africa -- Eastern Cape
- Description: The Katberg Sandstone is an arenaceous formation occuring stratigraphically three querters of the way up in the Beaufort Group in the south-eastern part of the main Karoo basin. A sedimentological study was carried out on the Katberg Sandstone and adjacent formations, in a 2 000 km² area south of Queenstown. Stratigraphic sections were measured and lithofacies based on the style of Miall (1977) were established for the Katberg Sandstone, Balfour and Burgersdorp Formations. Stratigraphic relationships show that the Burgersdorp Formation in the study area, is the lateral (distal) equivalent of the Katberg Sandstone. The changeover from sandstone to predominantly shale lithology occurs roughly east-west between Cathcart and Whittlesea. Stream hydraulic theory is discussed and the sedimentary structures of the various lithofacies are explained in terms of this theory. An analysis was done of thirty-four palaeochannels, and their various ancient flow characteristics were derived via multiple regression equations and a FORTRAN computer program. A statistical analysis of bedform structures, showed that flat-bedding of the upper flow regime is the dominant sedimentary structure of the Katberg Sandstone. Trough cross-bedding originating in aqueous dunes and planar cross-bedding of transverse bars, are fairly well represented while ripples are virtually absent. The opposite applies to the Balfour Formation where lower flow regime structures, viz., ripple cross-lamination and trough cross-bedding predominate. There is an even spread of (upper) flat-bedding, trough cross-bedding and ripple cross-lamination in the Burgersdorp Formation. Detailed measurement of typical short sequences from sections of the three formations, and transition matrix analyses, showed the facies assemblages to be of three stream types: (i) Katberg type: similar to Platte type of Miall (1977). Sediments were deposited by swiftly flowing, low sinuosity, braided, ephemeral streams with a predominantly sand bedload. Each flow started with preconsolidated silt and mud (flakes), and movement of exogenetic pebble lags. Channel avulsion and deposition of mud drapes in higher topographic levels of the stream were common phenomena. (ii) Balfour type: characterised by lateral accretion point bar type sequences of high sinuosity streams, and vertical accretion floodplain deposits. Lower flow regime dune and ripple bedform structures overlying (upper) flat-beds indicate a loss of stream power with channel migration. (iii) Burgersdorp type: similar to Katberg type for sandstone units, also crevasse-splays onto thick subaerially exposed floodplain aggradation reddish shales. Conventional microscopy and SEM studies showed tremendous diagenetic effects mostly in the form of secondary quartz growth in the sandstones of the three formations. Electron microprobe analyses were done on titanomagnetite grains from heavy mineral layers of the Katberg Sandstone, so that thermometric predictions could be made on provenance rocks. Palaeocurrents of the Katberg Sandstone are mostly Rank 4 and 5 types (Miall, 1974), i.e., they were generated within bars with not much change in stream orientation. Burgersdorp and Balfour formation palaeocurrents are Rank 1 - 3 types. In the case of the former this is owing to directional changes in channels as a result of frequent crevasse-splays, and in the case of the latter owing to differences in orientation between entire tracts of highly sinuous palaeostreams. Palaeocurrent directions in the Katberg Sandstone indicate a southeasterly provenance which accords with the findings of other Beaufort Group workers. Bed relief index calculations (Smith, 1970), made on Katberg rocks, considered together with the abundance of planar cross-bedding (of transverse bars) and apparent absence of longitudinal bars, testify to the deposition of the Katberg Sandstone in the distal parts of the braided stream environment. The Beaufort sediments of the study area have the sedimentological characteristics of a molasse sequence, but a different implied tectonogenesis. During Balfour sedimentation the equilibrium base was being raised very slowly at the source and complete fluvial sequences were deposited under a humid temperate climate, on a slowly subsiding plain. During Katberg/Burgersdorp times, source area tectonism was pronounced but interrupted and incomplete sequences were deposited under an arid climate. Provenance rocks for the formations studied included biotite mesoperthitic granite, granulite, charnockite, granite porphyry, granophyre, metaquartzite, greenschist and possibly diorite, epidosit e and alkaline volcanic rocks. , KMBT_363 , Adobe Acrobat 9.54 Paper Capture Plug-in
- Full Text:
- Date Issued: 1979
The behaviour of the elements Ni, Co, Cu, Pb, Zn, Au, Ag, Mo, Sn, W and U in the magmatic, hydrothermal, sedimentary and weathering environments
- Authors: Anderson, J R
- Date: 1979
- Subjects: Elements , Environment , Ore deposits , Classification , Geochemistry , Crystal chemistry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4896 , http://hdl.handle.net/10962/d1001555
- Description: In the last two decades much has been published on the behaviour of certain elements in the magmatic , hydrothermal, sedimentary and weathering environments , but the information is scattered throughout the literature . This situation prompted the present study on the elements Ni, Co, Cu, Pb , Zn , Au, Ag , Mo , Sn, W and U. The behaviour of the elements Ni, Cu, Pb , ZN, Au, Sn , W and U has been studied experimentally in some depth. Ag has been moderately studied, but there is very little information about Co and Mo. Studies on the complexes formed by the elements within the hydrothermal and aqueous environment are often inconclusive and controversial , but conclusions are drawn as to the more likely complexes formed . A genetic classification of ore deposits is used as a framework for the discussion . The source of the elements is regarded as being the mantle, and therefore discussion on other possible sources is beyond the scope of this dissertation. The crystal chemistry and geochemistry of the elements are presented and the essay concludes with a discussion on the elements within their depositional environments
- Full Text:
- Date Issued: 1979
- Authors: Anderson, J R
- Date: 1979
- Subjects: Elements , Environment , Ore deposits , Classification , Geochemistry , Crystal chemistry
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4896 , http://hdl.handle.net/10962/d1001555
- Description: In the last two decades much has been published on the behaviour of certain elements in the magmatic , hydrothermal, sedimentary and weathering environments , but the information is scattered throughout the literature . This situation prompted the present study on the elements Ni, Co, Cu, Pb , Zn , Au, Ag , Mo , Sn, W and U. The behaviour of the elements Ni, Cu, Pb , ZN, Au, Sn , W and U has been studied experimentally in some depth. Ag has been moderately studied, but there is very little information about Co and Mo. Studies on the complexes formed by the elements within the hydrothermal and aqueous environment are often inconclusive and controversial , but conclusions are drawn as to the more likely complexes formed . A genetic classification of ore deposits is used as a framework for the discussion . The source of the elements is regarded as being the mantle, and therefore discussion on other possible sources is beyond the scope of this dissertation. The crystal chemistry and geochemistry of the elements are presented and the essay concludes with a discussion on the elements within their depositional environments
- Full Text:
- Date Issued: 1979
The contribution of Spartina Maratima (Curtis) Fernald to the primary production of the Swartkops estuary
- Authors: Pierce, Shirley May
- Date: 1979
- Subjects: Estuarine biology -- South Africa -- Swartkops River Estuary , Spartina
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4174 , http://hdl.handle.net/10962/d1002022 , Estuarine biology -- South Africa -- Swartkops River Estuary , Spartina
- Description: The primary production of Spartina maritima, the dominant macrophyte of the intertidal salt marshes of the Swartkops estuary, was determined for inclusion into the proposed ecosystem model. Several methods for measuring net production devised for North temperate Spartina species were used, as no single method was considered reliable for the local species. In addition, a new method was devised to take into account the aseasonal growth behaviour of S. maritima . Most energy for growth appears to be directed into leaf production, rather than shoot growth. Live net production values were 523-680 g m⁻² yr ⁻¹, which are generally lower than estimates of N. American Spartina species. Total Live production of S. maritima for the whole Swartkops estuary was 495,6 x I0³kg yr ⁻¹, which is an estimation of potential food resources. Formation of S. maritima detritus by decomposition was significantly related to air and water temperatures. Thus detritus production showed a wide seasonal variation about a mean of 374 g m⁻² yr⁻¹. The total S. maritima detritus production of 307,5 x I0³kg for the whole Swartkops estuary was determined as an estimate of available food resources. Export of detrital material from Spartina marshes to estuarine waters was negligible. Even during a maximal Equinoctial tide, only 6,26 dry g m⁻² detritus was exported from the creek catchment area of Spartina stands. This study has shown that concepts evolved for North temperate estuaries should be carefully considered before being applied to local situations, particularly in view of the relatively low, aseasonal production of S. maritima and the negligible contribution of its detritus to estuarine waters. Furthermore, it is essential that utilisation of primary production by secondary producers be determined before the function of the estuarine ecosystem may be understood
- Full Text:
- Date Issued: 1979
- Authors: Pierce, Shirley May
- Date: 1979
- Subjects: Estuarine biology -- South Africa -- Swartkops River Estuary , Spartina
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4174 , http://hdl.handle.net/10962/d1002022 , Estuarine biology -- South Africa -- Swartkops River Estuary , Spartina
- Description: The primary production of Spartina maritima, the dominant macrophyte of the intertidal salt marshes of the Swartkops estuary, was determined for inclusion into the proposed ecosystem model. Several methods for measuring net production devised for North temperate Spartina species were used, as no single method was considered reliable for the local species. In addition, a new method was devised to take into account the aseasonal growth behaviour of S. maritima . Most energy for growth appears to be directed into leaf production, rather than shoot growth. Live net production values were 523-680 g m⁻² yr ⁻¹, which are generally lower than estimates of N. American Spartina species. Total Live production of S. maritima for the whole Swartkops estuary was 495,6 x I0³kg yr ⁻¹, which is an estimation of potential food resources. Formation of S. maritima detritus by decomposition was significantly related to air and water temperatures. Thus detritus production showed a wide seasonal variation about a mean of 374 g m⁻² yr⁻¹. The total S. maritima detritus production of 307,5 x I0³kg for the whole Swartkops estuary was determined as an estimate of available food resources. Export of detrital material from Spartina marshes to estuarine waters was negligible. Even during a maximal Equinoctial tide, only 6,26 dry g m⁻² detritus was exported from the creek catchment area of Spartina stands. This study has shown that concepts evolved for North temperate estuaries should be carefully considered before being applied to local situations, particularly in view of the relatively low, aseasonal production of S. maritima and the negligible contribution of its detritus to estuarine waters. Furthermore, it is essential that utilisation of primary production by secondary producers be determined before the function of the estuarine ecosystem may be understood
- Full Text:
- Date Issued: 1979
The culture of Penaeus Indicus Milne Edwards in experimental closed systems with special reference to water quality
- Authors: Gerhardt, Hedley Vernon
- Date: 1979
- Subjects: Penaeus Indicus , Aquatic animals , Water quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5595 , http://hdl.handle.net/10962/d1002045 , Penaeus Indicus , Aquatic animals , Water quality
- Description: This study embraces two aspects of closed system culture: (a) a comparative study of four different biological filtration treatments, and (b) a quantitative determination of the nitrogen flow in a particular biological filtration system. Twenty 0,5 g juvenile Penaeus indicus Milne Edwards were cultured for approximately two months in four different kinds of sea water recirculatory systems with bacterial filtration, algal filtration, algar plus bacterial filtration and water exchange (25% every 3 days). Growth was comparable to that found in the literature for P. indicus. Nitrification occurred in all systems irrespective of the type of biological filtration employed. Ammonia, nitrite and nitrate levels were reduced by the algae, but nitrate accumulated to approximately 30 mg NO¯³ -Nℓ¯¹ in those systems without algae. Depletion of trace elements (Cu, Fe, Zn, Hn and Co) by the algae did not occur due to trace metal replenishment from the addition of food. No marked changes occurred in the concentrations of the major cations (Ca⁺⁺, Mg⁺⁺, Na⁺ and K⁺), but a small increase in Ca⁺⁺ levels was detectable in those systems with oyster shell chips in the filtration medium. Only minor changes occurred in oxygen or pH values in the various systems tested. Inorganic carbon levels showed major increases in the algal filtration systems, while a slight drop occurred in the bacterial filtration systems. The increase in the algal filtration systems was thought to be due to the formation of carbonates and bicarbonates by the reaction of respiratory CO₂ with unionized ammonia and water. Suggestions are made as to how closed systems can be improved upon. By determining the rate of excretion of P.indicus as related to size and temperature, its faecal production, and the nitrogen content of P.indicus, its food and faeces, the nitrogen flow within a system could be calculated. P.indicus was found to have an assimilation efficiency of 88,93% and a food conversion ratio of 3,49:1. Of the total dietary nitrogen input into the system, P.indicus ingested 69,02% - 19,80% of which was used for growth, 41,58% excreted and 7,64% lost as faeces. The remaining 30,98% of the total nitrogen input can be regarded as excess food nitrogen. The total nitrogen loading on the biological filtration system was found to be 80,20% of the total input of dietary nitrogen. The ability of various types of filamentous algae to remove these nitrogen compounds was determined. Suggestions are made as to the application of this information on nitrogen flow to the culture of P.indicus
- Full Text:
- Date Issued: 1979
- Authors: Gerhardt, Hedley Vernon
- Date: 1979
- Subjects: Penaeus Indicus , Aquatic animals , Water quality
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5595 , http://hdl.handle.net/10962/d1002045 , Penaeus Indicus , Aquatic animals , Water quality
- Description: This study embraces two aspects of closed system culture: (a) a comparative study of four different biological filtration treatments, and (b) a quantitative determination of the nitrogen flow in a particular biological filtration system. Twenty 0,5 g juvenile Penaeus indicus Milne Edwards were cultured for approximately two months in four different kinds of sea water recirculatory systems with bacterial filtration, algal filtration, algar plus bacterial filtration and water exchange (25% every 3 days). Growth was comparable to that found in the literature for P. indicus. Nitrification occurred in all systems irrespective of the type of biological filtration employed. Ammonia, nitrite and nitrate levels were reduced by the algae, but nitrate accumulated to approximately 30 mg NO¯³ -Nℓ¯¹ in those systems without algae. Depletion of trace elements (Cu, Fe, Zn, Hn and Co) by the algae did not occur due to trace metal replenishment from the addition of food. No marked changes occurred in the concentrations of the major cations (Ca⁺⁺, Mg⁺⁺, Na⁺ and K⁺), but a small increase in Ca⁺⁺ levels was detectable in those systems with oyster shell chips in the filtration medium. Only minor changes occurred in oxygen or pH values in the various systems tested. Inorganic carbon levels showed major increases in the algal filtration systems, while a slight drop occurred in the bacterial filtration systems. The increase in the algal filtration systems was thought to be due to the formation of carbonates and bicarbonates by the reaction of respiratory CO₂ with unionized ammonia and water. Suggestions are made as to how closed systems can be improved upon. By determining the rate of excretion of P.indicus as related to size and temperature, its faecal production, and the nitrogen content of P.indicus, its food and faeces, the nitrogen flow within a system could be calculated. P.indicus was found to have an assimilation efficiency of 88,93% and a food conversion ratio of 3,49:1. Of the total dietary nitrogen input into the system, P.indicus ingested 69,02% - 19,80% of which was used for growth, 41,58% excreted and 7,64% lost as faeces. The remaining 30,98% of the total nitrogen input can be regarded as excess food nitrogen. The total nitrogen loading on the biological filtration system was found to be 80,20% of the total input of dietary nitrogen. The ability of various types of filamentous algae to remove these nitrogen compounds was determined. Suggestions are made as to the application of this information on nitrogen flow to the culture of P.indicus
- Full Text:
- Date Issued: 1979
The development of an improved coded-pulse, vertical-incidence ionosonde
- Authors: Cretchley, Brian Brind
- Date: 1979
- Subjects: Ionosondes Ionospheric sounds Computer simulation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5436 , http://hdl.handle.net/10962/d1001989
- Description: This thesis describes the theoretical development of a new ionospheric sounding system. The different types of ionosonde, their prime objectives, and their relative merits and demerits are discussed. The various types of code and their correlation functions are described. The essential requirements of the new system are listed, and suitable codes are found for it. Computer calculations and mathematical derivations demonstrate the (theoretical) suitability of these codes under all conditions. Essentials of the mode of operation of the system and details of its design are specified, and computer simulations are used to examine relevant aspects of its operation. Finally, since the construction of the system is not complete and results cannot therefore be presented, the present state of construction of the system is described
- Full Text:
- Date Issued: 1979
- Authors: Cretchley, Brian Brind
- Date: 1979
- Subjects: Ionosondes Ionospheric sounds Computer simulation
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5436 , http://hdl.handle.net/10962/d1001989
- Description: This thesis describes the theoretical development of a new ionospheric sounding system. The different types of ionosonde, their prime objectives, and their relative merits and demerits are discussed. The various types of code and their correlation functions are described. The essential requirements of the new system are listed, and suitable codes are found for it. Computer calculations and mathematical derivations demonstrate the (theoretical) suitability of these codes under all conditions. Essentials of the mode of operation of the system and details of its design are specified, and computer simulations are used to examine relevant aspects of its operation. Finally, since the construction of the system is not complete and results cannot therefore be presented, the present state of construction of the system is described
- Full Text:
- Date Issued: 1979
The study of hydroxyoximes and hydroxamic acids supported on macroporous resins and their use in the rapid seperation of metals
- Authors: Hemmes, Marlene
- Date: 1979
- Subjects: Chromatographic analysis , Separation (Technology) , Metal ions , Solvent extraction , Extraction (Chemistry) , Oximes , Metals -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4453 , http://hdl.handle.net/10962/d1009512
- Description: Introduction: The macroporous Amberlite XAD resins were coated with LIX-64N and examined for the rate of uptake of copper . XAD-7 was by far the best support and gave a satisfactory rate of uptake up to loadings of 60% (w/w). The specific surface area of XAD-7 was measured by the adsorption of methylene blue from aqueous solution. The area of the wetted resin was five times less than that of the dry resin. LIX-65N was purified and the anti isomer characterised using spectroscopic techniques . The rate of uptake of copper was not improved by use of purified LIX-65N or by addition of LIX-63. XAD-7 coated with LIX-65N was used in columns. Elution curves for copper showed negligible tailing, and rapid separations of copper from iron (111), nickel, cobalt and magnesium by selective absorption were achieved. Copper was concentrated from very dilute solution at a flow rate of 50 ml min -1 ,and a 99% recovery was obtained. The method was applied to the rapid determination of copper in brass and bronze. A series of long-chain hydroxamic acids were synthesised and tested for suitability as stationary phase on XAD-7. Oleohydroxamic acid and naphthenohydroxamic acid were the most promising. The r ate of uptake of copper was reduced by the use of nonylphenol or amyl alcohol as a diluent. The capacities for copper of the hydroxamic acids were less when supported on XAD-7 than when used as liquid ionexchangers. The distribution coefficients of cobalt, nickel, zinc, lead, vanadium, uranium, iron (111) and copper were measured as a function of pH. XAD-7 coated with oleohydroxamic acid was used in columns for the rapid separation of iron (111) from copper and of copper from nickel, cobalt, lead and zinc. Copper was concentrated from very dilute solution at a flow rate of 45 ml min -1 and a 100,8% recovery was obtained. Copper was successfully separated from nickel by selective elution. The elution curves obtained show negligible tailing. The resin loaded with oleohydroxamic acid lost capacity due to chemical instability. Naphthenohydroxamic acid supported on XAD-7 was not suitable for use in columns, because it was physically unstable.
- Full Text:
- Date Issued: 1979
- Authors: Hemmes, Marlene
- Date: 1979
- Subjects: Chromatographic analysis , Separation (Technology) , Metal ions , Solvent extraction , Extraction (Chemistry) , Oximes , Metals -- Analysis
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:4453 , http://hdl.handle.net/10962/d1009512
- Description: Introduction: The macroporous Amberlite XAD resins were coated with LIX-64N and examined for the rate of uptake of copper . XAD-7 was by far the best support and gave a satisfactory rate of uptake up to loadings of 60% (w/w). The specific surface area of XAD-7 was measured by the adsorption of methylene blue from aqueous solution. The area of the wetted resin was five times less than that of the dry resin. LIX-65N was purified and the anti isomer characterised using spectroscopic techniques . The rate of uptake of copper was not improved by use of purified LIX-65N or by addition of LIX-63. XAD-7 coated with LIX-65N was used in columns. Elution curves for copper showed negligible tailing, and rapid separations of copper from iron (111), nickel, cobalt and magnesium by selective absorption were achieved. Copper was concentrated from very dilute solution at a flow rate of 50 ml min -1 ,and a 99% recovery was obtained. The method was applied to the rapid determination of copper in brass and bronze. A series of long-chain hydroxamic acids were synthesised and tested for suitability as stationary phase on XAD-7. Oleohydroxamic acid and naphthenohydroxamic acid were the most promising. The r ate of uptake of copper was reduced by the use of nonylphenol or amyl alcohol as a diluent. The capacities for copper of the hydroxamic acids were less when supported on XAD-7 than when used as liquid ionexchangers. The distribution coefficients of cobalt, nickel, zinc, lead, vanadium, uranium, iron (111) and copper were measured as a function of pH. XAD-7 coated with oleohydroxamic acid was used in columns for the rapid separation of iron (111) from copper and of copper from nickel, cobalt, lead and zinc. Copper was concentrated from very dilute solution at a flow rate of 45 ml min -1 and a 100,8% recovery was obtained. Copper was successfully separated from nickel by selective elution. The elution curves obtained show negligible tailing. The resin loaded with oleohydroxamic acid lost capacity due to chemical instability. Naphthenohydroxamic acid supported on XAD-7 was not suitable for use in columns, because it was physically unstable.
- Full Text:
- Date Issued: 1979
The taxonomy and osteology of fishes of the family Tripterygiidae (Perciformes : Blennioidei) of South Africa
- Authors: Holleman, Wouter
- Date: 1979
- Subjects: Tripterygiidae -- South Africa , Blennioidei -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5185 , http://hdl.handle.net/10962/d1001961 , Tripterygiidae -- South Africa , Blennioidei -- South Africa
- Description: This study is divided into two parts. The first deals with the taxonomy of the South African fishes of the Tripterygiidae. The second part describes the osteology of one genus of the family, and draws comparisons with the other genera discussed in this study. Five genera of Tripterygiidae are recognized from South African waters. Cremnochorites, a monotypic genus, is described as new. The single species, C. capensis, has been recorded only from the southern and south-eastern coast of South Africa. It is distinguished from other genera by a combination of features which includes scalation, dorsal and anal fin spine counts, and various osteological characters. Three genera, Norfolkia Fowler, Helcogramma McCulloch & Waite, and Enneapterygius Rüppell occur throughout most of the Indo-Pacific. A single species of Norfolkia, N. springeri Clark (in press) is found in Zululand. Two species are ascribed to Helcogramma, H. obtusirostre (Klunzinger) and H. fuscopinna sp.n. Parallels are drawn between two species of Tripterygion Risso, T. tripteronotus and T. delaisi from the Mediterranean. The two South African Helcogramma species show similar depth preferences to the two Tripterygion species, resulting in similar morphological differences between the two species of each pair. The genus Enneapterygius Rüppell is divided into two genera, Enneanterygius and Scoliosolen gen.n. The division is based on the form of the supraoccipital sensory canal and associated osteological characters. Sooliosolen has a crescent-shaped supraoccipital canal and cranial osteology similar to the majority of other tripterygiid genera, whereas Enneapterygius has a 'U'-shaped supraoccipital canal which curves around the first dorsal fin, a comparatively long, concave supraoccipital bone which extends anteriorly between the parietal and between the posterior ends of the frontals. Two species are referred to Scoliosolen, S. abeli (Klausewitz) and S. conspicuus (Clark), and two new species are described for Enneapterygius, E. pulcherrimus and E. trianeulus. A literature survey revealed little consistency in ascribing species to any particular genus. Thus, throughout this study an attempt is made to define the genera so that future confusion can be avoided. In the light of these definitions an assessment is made of the original descriptions of a large number of species to determine which of the species can be ascribed to Norfolkia and to Helcogramrna. This has been possible to a lesser degree for Enneapterygius and Scoliosolen, for the major external feature separating these two genera, the shape of the supraoccipital sensory canal, is described only for Red Sea (Clark, in press) and South African species (this study). This study places four species in Enneapterygius, and six in Scoliosolen. To provide a firmer foundation for defining the genera, an investigation was made of the osteology of Scoliosolen conspicuus. Enneapterygius was originally chosen for the osteolofical study as it is reputedly the largest genus of the family, and thus likely to be the most generalized. Once comparisons had been made with other Enneapterygius species, it became apparent that this genus had to be divided into two genera, Enneapterygius and Scoliosolen. It is not known whether Scoliosolen is the largest genus, but it is likely to be one of the largest once a complete survey of the species originally ascribed to Enneapterygius has been undertaken. Finally, an osteological comparison is made of the five genera which occur in South African waters to provide firmer bases for the generic definitions. Only those characters which appear to be constant within a genus are used. Reference is made to a number of genera which do not occur in South African waters, to ensure that the characters chosen cannot be applied to other genera
- Full Text:
- Date Issued: 1979
- Authors: Holleman, Wouter
- Date: 1979
- Subjects: Tripterygiidae -- South Africa , Blennioidei -- South Africa
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5185 , http://hdl.handle.net/10962/d1001961 , Tripterygiidae -- South Africa , Blennioidei -- South Africa
- Description: This study is divided into two parts. The first deals with the taxonomy of the South African fishes of the Tripterygiidae. The second part describes the osteology of one genus of the family, and draws comparisons with the other genera discussed in this study. Five genera of Tripterygiidae are recognized from South African waters. Cremnochorites, a monotypic genus, is described as new. The single species, C. capensis, has been recorded only from the southern and south-eastern coast of South Africa. It is distinguished from other genera by a combination of features which includes scalation, dorsal and anal fin spine counts, and various osteological characters. Three genera, Norfolkia Fowler, Helcogramma McCulloch & Waite, and Enneapterygius Rüppell occur throughout most of the Indo-Pacific. A single species of Norfolkia, N. springeri Clark (in press) is found in Zululand. Two species are ascribed to Helcogramma, H. obtusirostre (Klunzinger) and H. fuscopinna sp.n. Parallels are drawn between two species of Tripterygion Risso, T. tripteronotus and T. delaisi from the Mediterranean. The two South African Helcogramma species show similar depth preferences to the two Tripterygion species, resulting in similar morphological differences between the two species of each pair. The genus Enneapterygius Rüppell is divided into two genera, Enneanterygius and Scoliosolen gen.n. The division is based on the form of the supraoccipital sensory canal and associated osteological characters. Sooliosolen has a crescent-shaped supraoccipital canal and cranial osteology similar to the majority of other tripterygiid genera, whereas Enneapterygius has a 'U'-shaped supraoccipital canal which curves around the first dorsal fin, a comparatively long, concave supraoccipital bone which extends anteriorly between the parietal and between the posterior ends of the frontals. Two species are referred to Scoliosolen, S. abeli (Klausewitz) and S. conspicuus (Clark), and two new species are described for Enneapterygius, E. pulcherrimus and E. trianeulus. A literature survey revealed little consistency in ascribing species to any particular genus. Thus, throughout this study an attempt is made to define the genera so that future confusion can be avoided. In the light of these definitions an assessment is made of the original descriptions of a large number of species to determine which of the species can be ascribed to Norfolkia and to Helcogramrna. This has been possible to a lesser degree for Enneapterygius and Scoliosolen, for the major external feature separating these two genera, the shape of the supraoccipital sensory canal, is described only for Red Sea (Clark, in press) and South African species (this study). This study places four species in Enneapterygius, and six in Scoliosolen. To provide a firmer foundation for defining the genera, an investigation was made of the osteology of Scoliosolen conspicuus. Enneapterygius was originally chosen for the osteolofical study as it is reputedly the largest genus of the family, and thus likely to be the most generalized. Once comparisons had been made with other Enneapterygius species, it became apparent that this genus had to be divided into two genera, Enneapterygius and Scoliosolen. It is not known whether Scoliosolen is the largest genus, but it is likely to be one of the largest once a complete survey of the species originally ascribed to Enneapterygius has been undertaken. Finally, an osteological comparison is made of the five genera which occur in South African waters to provide firmer bases for the generic definitions. Only those characters which appear to be constant within a genus are used. Reference is made to a number of genera which do not occur in South African waters, to ensure that the characters chosen cannot be applied to other genera
- Full Text:
- Date Issued: 1979
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