scholarly journals Geothermal energy from the Main Karoo Basin? New insights from borehole KWV-1 (Eastern Cape, South Africa)

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Stuart A. Campbell ◽  
Philipp Mielke ◽  
Annette E. Götz
Keyword(s):  
South Africa ◽  
Geothermal Energy ◽  
Eastern Cape ◽  
Karoo Basin

scholarly journals Diagenesis and rock properties of sandstones from the Stormberg Group, Karoo Supergroup in the Eastern Cape Province of South Africa

2018 ◽  
Vol 10 (1) ◽  
pp. 740-771 ◽  
Author(s):  
Priscilla Chima ◽  
Christopher Baiyegunhi ◽  
Kuiwu Liu ◽  
Oswald Gwavava
Keyword(s):  
South Africa ◽  
Mineral Exploration ◽  
Rock Properties ◽  
Reservoir Quality ◽  
Eastern Cape ◽  
X Ray ◽  
Porosity Evolution ◽  
Karoo Basin ◽  
It Impacts ◽  
Diagenetic Processes

Abstract Diagenesis is one of the factors that affect reservoir quality in sandstones. Knowledge of diagenetic transformation and how it impacts the development of porosity in reservoirs rocks is thus key to successful mineral exploration. To date, little is known about the diagenesis of the uranium-hosted sandstones of the Stormberg Group, Karoo Basin, South Africa. Petrographic study, scanning electron microscopy (SEM) aided with energy dispersive X-ray (EDX), and X-ray diffraction (XRD) analyses were employed for the diagenetic study of the sandstones. This study aims to provide an account of the diagenesis of these rock units and how it impacts their reservoir quality. The diagenetic processes that have affected the sandstones are cementation, compaction, recrystallization, replacement, mineral overgrowth and dissolution. These processes have passed through early, late and uplift-related diagenesis. Formation of authigenic minerals and precipitation of the mineral cements occurred during different diagenetic phase but mostly during the early diagenetic stage. This stage was followed by lithification, which resulted in increased in grain packing, loss of pore spaces and thinning of bedding. Quartz and feldspar overgrowths, chloritization, muscovitization, concave-convex contacts, recrystallization, albitization and suture contacts are present in the late diagenetic stage. The uplift-related diagenetic stage was affected by calcitization, grain deformation and fracturing, dissolution and saussuritization. All these diagenetic processes largely affected the porosity and permeability of the sandstones. Primary and secondary porosities were both observed in the sandstones. In general, there is no single diagenetic process that is controlling the pattern of porosity evolution in the sandstones. On the other hand, the presence of fractured and dissolution pores tend to increase the porosity, thus enhancing the reservoir quality. This study shows that diagenesis has significantly altered the original petrologic characteristics of the sandstones which have induced considerable deterioration and heterogeneity in the reservoir quality of the Stormberg Group sandstones in the Main Karoo Basin of South Africa.

scholarly journals Modal composition and tectonic provenance of the sandstones of Ecca Group, Karoo Supergroup in the Eastern Cape Province, South Africa

2017 ◽  
Vol 9 (1) ◽  
Author(s):  
Christopher Baiyegunhi ◽  
Kuiwu Liu ◽  
Oswald Gwavava
Keyword(s):  
South Africa ◽  
Sedimentary Rocks ◽  
Foreland Basin ◽  
Source Area ◽  
Climatic Conditions ◽  
Eastern Cape Province ◽  
Eastern Cape ◽  
Rock Fragments ◽  
Karoo Basin ◽  
Transport Distance

AbstractPetrography of the sandstones of Ecca Group, Karoo Supergroup in the Eastern Cape Province of South Africa have been investigated on composition, provenance and influence of weathering conditions. Petrographic studies based on quantitative analysis of the detrital minerals revealed that the sandstones are composed mostly of quartz, feldspar and lithic fragments of metamorphic and sedimentary rocks. The sandstones have an average framework composition of 24.3% quartz, 19.3% feldspar, 26.1% rock fragments, and 81.33% of the quartz grains are monocrystalline. These sandstones are generally very fine to fine grained, moderate to well sorted, and subangular to subrounded in shape. In addition, they are compositionally immature and can be classified as feldspathic wacke and lithic wacke. The provenance characteristics suggest the influence of plutonic and metamorphic terrains (meta-magmatic arc) as the main source rock with minor debris derived from recycled sedimentary rocks. The latter revealed that the compositional immaturity of the sandstones is a result of weathering or recycling and short transport distance. The weathering diagrams and semi-quantitative weathering index indicate that the Ecca sandstones are mostly from a plutonic source area, with climatic conditions ranging from arid to humid. The detrital modal compositions of these sandstones are related to back arc to island and continental margin arc. These results, therefore, support previous studies that infer foreland basin setting for the Karoo Basin.

scholarly journals Sedimentary facies, stratigraphy, and depositional environments of the Ecca Group, Karoo Supergroup in the Eastern Cape Province of South Africa

2021 ◽  
Vol 13 (1) ◽  
pp. 748-781
Author(s):  
Christopher Baiyegunhi ◽  
Kuiwu Liu
Keyword(s):  
South Africa ◽  
Water Depth ◽  
Facies Analysis ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Eastern Cape Province ◽  
Eastern Cape ◽  
Borehole Data ◽  
Karoo Basin ◽  
Facies Associations

Abstract The stratigraphy of the Ecca Group has been subdivided into the Prince Albert, Whitehill, Collingham, Ripon, and Fort Brown Formations in the Eastern Cape Province, South Africa. In this article, we present detailed stratigraphic and facies analyses of borehole data and road-cut exposures of the Ecca Group along regional roads R67 (Ecca Pass), R344 (Grahamstown-Adelaide), R350 (Kirkwood-Somerset East), and national roads N2 (Grahamstown-Peddie) and N10 (Paterson-Cookhouse). Facies analysis of the Ecca Group in the study area was performed to deduce their depositional environments. Based on the lithological and facies characteristics, the stratigraphy of the Prince Albert, Whitehill, Collingham, and Fort Brown Formations is now subdivided into two informal members each, while the Ripon Formation is subdivided into three members. A total of twelve lithofacies were identified in the Ecca Group and were further grouped into seven distinct facies associations (FAs), namely: Laminated to thin-bedded black-greyish shale and mudstones (FA 1); Laminated black-greyish shale and interbedded chert (FA 2); Mudstone rhythmite and thin beds of tuff alternation (FA 3); Thin to thick-bedded sandstone and mudstone intercalation (FA 4); Medium to thick-bedded dark-grey shale (FA 5); Alternated thin to medium-bedded sandstone and mudstone (FA 6); and Varved mudstone rhythmite and sandstone intercalation (FA 7). The FAs revealed gradually change of sea-level from deep marine (FA 1, FA 2, FA 3 and FA 4, FA 5, and FA 6) to prodelta environment (FA 7). This implies that the main Karoo Basin was gradually filling up with Ecca sediments, resulting in the gradual shallowing up of the water depth of the depositional basin.

scholarly journals A tale of two Tweefonteins: What physical correlation, geochronology, magnetic polarity stratigraphy, and palynology reveal about the end-Permian terrestrial extinction paradigm in South Africa

2021 ◽  
Author(s):  
Robert A. Gastaldo ◽  
Johann Neveling ◽  
John W. Geissman ◽  
Sandra L. Kamo ◽  
Cindy V. Looy
Keyword(s):  
South Africa ◽  
Magnetic Polarity ◽  
Free State ◽  
Upper Permian ◽  
Ionization Mass ◽  
Eastern Cape Province ◽  
Eastern Cape ◽  
Data Set ◽  
Karoo Basin ◽  
Permian Mass Extinction

The contact between the Daptocephalus to Lystrosaurus declivis (previously Lystrosaurus) Assemblage Zones (AZs) described from continental deposits of the Karoo Basin was commonly interpreted to represent an extinction crisis associated with the end-Permian mass-extinction event at ca. 251.901 ± 0.024 Ma. This terrestrial extinction model is based on several sections in the Eastern Cape and Free State Provinces of South Africa. Here, new stratigraphic and paleontologic data are presented for the Eastern Cape Province, in geochronologic and magnetostratigraphic context, wherein lithologic and biologic changes are assessed over a physically correlated stratigraphy exceeding 4.5 km in distance. Spatial variation in lithofacies demonstrates the gradational nature of lithostratigraphic boundaries and depositional trends. This pattern is mimicked by the distribution of vertebrates assigned to the Daptocephalus and L. declivis AZs where diagnostic taxa of each co-occur as lateral equivalents in landscapes dominated by a Glossopteris flora. High-precision U-Pb zircon (chemical abrasion-isotope dilution-thermal ionization mass spectrometry) age results indicate maximum Changhsingian depositional dates that can be used as approximate tie points in our stratigraphic framework, which is supported by a magnetic polarity stratigraphy. The coeval nature of diagnostic pre- and post-extinction vertebrate taxa demonstrates that the L. declivis AZ did not replace the Daptocephalus AZ stratigraphically, that a biotic crisis and turnover likely is absent, and a reevaluation is required for the utilization of these biozones here and globally. Based on our data set, we propose a multidisciplinary approach to correlate the classic Upper Permian localities of the Eastern Cape Province with the Free State Province localities, which demonstrates their time-transgressive nature.

scholarly journals New Specimen of the Enigmatic Dicynodont Lanthanostegus mohoii (Therapsida, Anomodontia) from the Southwestern Karoo Basin of South Africa, and its Implications for Middle Permian Biostratigraphy

2021 ◽  
Vol 9 ◽  
Author(s):  
Bruce S. Rubidge ◽  
Michael O. Day ◽  
Julien Benoit
Keyword(s):  
South Africa ◽  
Depositional Environment ◽  
Middle Permian ◽  
Western Cape ◽  
Eastern Cape ◽  
Karoo Basin ◽  
Lower Jaw ◽  
Assemblage Zone ◽  
Western Side ◽  
Single Locality

Lanthanostegus is an unusual dicynodont known from only two partial skulls from a single locality near Jansenville in the Eastern Cape Province of South Africa. Although these specimens can be constrained to near the base of the late middle Permian (Guadalupian) Abrahamskraal Formation, their precise age is uncertain as a result of diachroneity of the base of the Formation and the absence, in the Jansenville area, of index taxa to correlate this horizon with the biostratigraphy established in the Western Cape Province. Here, we describe a third skull that we identify as Lanthanostegus, which we recently discovered from a locality north of Laingsburg, on the western side of the main Karoo Basin. This skull reveals morphological details of the palate, occiput, and lower jaw that are not preserved in the described specimens of Lanthanostegus mohoii and will advance understanding of this poorly known dicynodont. This discovery provides the first direct correlation between the lower Abrahamskraal Formation at Jansenville on the eastern side of the basin and the southwestern part of the basin, and suggests that Lanthanostegus occurs in the lowest Tapinocephalus Assemblage Zone (AZ), or possibly to a new assemblage transitional between the Eodicynodon and Tapinocephalus AZs. This supports earlier work proposing that the Eodicynodon AZ is present only on the western side of the Karoo Basin and that the transition from a marine to continental depositional environment occurred later toward the East.

scholarly journals Geothermal Energy from the Main Karoo Basin (South Africa): An Outcrop Analogue Study of Permian Sandstone Reservoir Formations

2016 ◽  
Vol 97 ◽  
pp. 186-193 ◽  
Author(s):  
Stuart A. Campbell ◽  
Nils Lenhardt ◽  
Matthys A. Dippenaar ◽  
Annette E. Götz
Keyword(s):  
South Africa ◽  
Geothermal Energy ◽  
Karoo Basin ◽  
Analogue Study ◽  
Sandstone Reservoir

Influence of Knowledge Management Practices on Public Service Delivery by Municipalities

Mousaion ◽  
2019 ◽  
Vol 37 (3) ◽  
Author(s):  
Charleen Musonza ◽  
Ndakasharwa Muchaonyerwa
Keyword(s):  
South Africa ◽  
Knowledge Management ◽  
Service Delivery ◽  
Public Service ◽  
Qualitative Data ◽  
Management Practices ◽  
Integrated System ◽  
Eastern Cape Province ◽  
Eastern Cape ◽  
Public Service Delivery

This study examines the influence of knowledge management (KM) practices on public service delivery by municipalities in the Eastern Cape province of South Africa. The study sought to determine the factors that have triggered the implementation of KM practices; the effectiveness of KM practices towards public service delivery; and the extent to which KM practices have influenced public service delivery by municipalities in the Eastern Cape province of South Africa. Both quantitative and qualitative methods were employed in this study. Quantitative data were collected through a survey questionnaire administered to a sample of 202 employees at the Raymond Mhlaba Municipality in the Eastern Cape. Qualitative data were collected through observations and interviews of 2 senior managers. The data collected gave a response rate of 72 per cent. The quantitative and qualitative data were analysed descriptively and presented verbatim respectively. The results indicated that the internal and external factors included in this study have contributed to the implementation of KM practices in the municipality. Furthermore, the effective use of KM practices has increased the organisational KM initiative, as well as the provision of services such as electricity, education, transport, and social services by the municipality. The study recommends the establishment of KM awareness and the establishment of an integrated system that will assist in effective knowledge sharing, retention and acquisition across municipalities in the Eastern Cape.

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