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.

The Genus Pithomyces in South Africa

Bothalia ◽  
1972 ◽  
Vol 10 (4) ◽  
pp. 509-516 ◽  
Author(s):  
W. F. O. Marasas ◽  
Ingrid H. Schumann
Keyword(s):  
South Africa ◽  
Medicago Sativa ◽  
South African ◽  
Lolium Perenne ◽  
Avena Sativa ◽  
Free State ◽  
Eastern Cape Province ◽  
Eastern Cape ◽  
Lolium Perenne L ◽  
Medicago Sativa L

Descriptions are given of South African isolates of  Pithomyces sacchari (Speg.) M. B. Ellis, Pithomyces chartarum (Berk. Curt.) M. B. Ellis and  Pithomyces karoo  Marasas Schumann, sp. nov.  P. sacchari and P. chartarum were isolated from Medicago sativa L. seed.  P. chartarum was also isolated from dead leaves of Lolium perenne L. and  Sporobolus capensis (Willd.) Kunth. plants from artificial pastures in the eastern Cape Province.  P. karoo was isolated from stems of Gnidia polycephala (C.A. Mey.) Gilg and  Rhigozum trichotomum Burch, from the Karoo, Cape Province and from Avena sativa L. stubble collected in the Orange Free State.

scholarly journals Range expansion of the economically important Asiatic blue tick, Rhipicephalus microplus, in South Africa

2017 ◽  
Vol 88 ◽  
Author(s):  
Nkululeko Nyangiwe ◽  
Ivan G. Horak ◽  
Luther Van der Mescht ◽  
Sonja Matthee
Keyword(s):  
South Africa ◽  
Rhipicephalus Microplus ◽  
Free State ◽  
Detailed Knowledge ◽  
Western Region ◽  
Eastern Region ◽  
Western Cape ◽  
Eastern Cape Province ◽  
Eastern Cape ◽  
Northern Cape

The Asiatic blue tick, Rhipicephalus microplus, a known vector of bovine babesiosis and bovine anaplasmosis, is of great concern in the cattle industry. For this reason, detailed knowledge of the distribution of R. microplus is vital. Currently, R. microplus is believed to be associated mainly with the northern and eastern Savanna and Grassland vegetation in South Africa. The objective of the study was to record the distribution of R. microplus, and the related endemic Rhipicephalus decoloratus, in the central-western region of South Africa that comprises Albany Thicket, Fynbos and Savanna vegetation. In this survey, ticks were collected from 415 cattle in four provinces (Eastern Cape, Northern Cape and Western Cape and Free State provinces) and from the vegetation in the Eastern Cape province of South Africa between October 2013 and September 2015. More than 8000 ticks were collected from cattle at 80 localities of which R. microplus was present at 64 localities and R. decoloratus at 47 localities. A total of 7969 tick larvae were recorded from the vegetation at 20 localities of which 6593 were R. microplus and 1131 were R. decoloratus. Rhipicephalus microplus was recorded in each of the regions that were sampled. Rhipicephalus microplus is now present throughout the coastal region of the Eastern Cape province and at multiple localities in the north-eastern region of the Northern Cape province. It was also recorded in the western region of the Western Cape province and one record was made for the Free State province. The observed range changes may be facilitated by the combined effects of environmental adaptability by the tick and the movement of host animals.

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.

TESTING THE DAPTOCEPHALUS AND LYSTROSAURUS ASSEMBLAGE ZONES IN A LITHOSTRATOGRAPHIC, MAGNETOSTRATIGRAPHIC, AND PALYNOLOGICAL FRAMEWORK IN THE FREE STATE, SOUTH AFRICA

Palaios ◽  
2019 ◽  
Vol 34 (11) ◽  
pp. 542-561 ◽  
Author(s):  
ROBERT A. GASTALDO ◽  
JOHANN NEVELING ◽  
JOHN W. GEISSMAN ◽  
CINDY V. LOOY
Keyword(s):  
Terrestrial Ecosystems ◽  
Free State ◽  
Eastern Cape ◽  
Zone Boundary ◽  
Data Set ◽  
Karoo Basin ◽  
Stratigraphic Position ◽  
Marine Realm ◽  
Normal Polarity ◽  
Assemblage Zone

ABSTRACT The vertebrate-fossil record in the Karoo Basin has served as the accepted model for how terrestrial ecosystems responded to the end-Permian extinction event. A database of several hundred specimens, placed into generalized stratigraphies, has formed the basis of a step-wise extinction scenario interpreted by other workers as spanning the upper Daptocephalus (=Dicynodon) to Lystrosaurus Assemblage Zones (AZ). Seventy-three percent of specimens used to construct the published model originate from three farms in the Free State: Bethel, Heldenmoed, and Donald 207 (Fairydale). The current contribution empirically tests: (1) the stratigraphic resolution of the vertebrate record on these farms; (2) whether a sharp boundary exists that delimits the vertebrate assemblage zones in these classic localities; and (3) if the Lystrosaurus AZ is of early Triassic age. We have used a multi-disciplinary approach, combining lithostratigraphy, magnetostratigraphy, vertebrate biostratigraphy, and palynology, to test these long-held assumptions. Previously reported vertebrate-collection sites have been physically placed into a litho- and magnetostratigraphic framework on the Bethel and Heldenmoed farms. The reported assemblage-zone boundary is used as the datum against which the stratigraphic position of vertebrates is compared and a preliminary magnetostratigraphy constructed. We find specimens of the Daptocephalus AZ originate in the Lystrosaurus AZ (as currently defined) and vice versa, and discrepancies between reported and field-checked stratigraphic positions below or above the assemblage-zone boundary often exceed 30 m. Hence, the utility of the data set in defining a sharp or abrupt biozone boundary is questionable. We further demonstrate the presence of a stratigraphically thick reverse polarity magnetozone that encompasses the reported assemblage-zone boundary, implying that these rocks are not correlative with the end-Permian event, which is reported to lie in a normal polarity chron. A latest Permian age is supported by palynological data from the Lystrosaurus AZ on the Donald 207 (Fairydale) farm, with equivalence to Australian (APP602) and Eastern Cape Province assemblages. We conclude that the turnover from the Daptocephalus to Lystrosaurus Assemblage Zones is more protracted than envisioned, it is not coincident with the end-Permian event as recognized in the marine realm, and little evidence exists in support of a three-phased extinction model based on vertebrate assemblages in the Karoo Basin.

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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