Stratigraphy and palaeoenvironment of the Carboniferous Jurassic Karoo Supergroup in the Lebombo-Tshipise basin
Date
2017
Authors
Clayton, Katherine E
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Abstract
The Karoo Supergroup represents a highly complete sedimentary succession
that was deposited in several basins throughout southern Africa during the late
Palaeozoic and Mesozoic (Carboniferous-Jurassic). While research in the
Lebombo-Tshipise Basin of southern Africa has largely focused on lithological
description of Karoo sediments or structural features of the basin, little effort has
been made to describe the palaeoenvironments recorded in the sediments, or the
basin fill’s response to major tectonic or climatic events.
To address palaeoenvironmental reconstruction, lithostratigraphic analysis
resulted in defining 11 facies associations from the Tshidize, Madzaringwe,
Mikembeni, Fripp, Solitude, Elliot and Clarens Formations in the Pafuri sub-basin
of the Lebombo-Tshipise Basin. Twenty boreholes drilled in Kruger National Park
by the Council for Geoscience in 1979 record largely stable and consistent
deposition of the Tshidize, Madzaringwe and Mikembeni Formations during the
Permian. The Mikembeni Formation thins dramatically southwards, whereas the
overlying Triassic successions tend to wedge out to the east. Late Triassic and
Jurassic sediments directly overlie Precambrian basement in the southernmost
boreholes. Significant thickness differences between the western and eastern
boreholes indicate a large fault, which likely represents a rift shoulder.
The palaeoenvironments in this basin are similar to those of the Main Karoo
Basin, but quantitative analyses suggest a more humid environment in the Late
Triassic Elliot Formation. Sauropodomorph fossils validate assignment of
formerly mapped Solitude Formation as actually being the Elliot Formation.
Palaeosols in the Elliot are consistent with either Oxisols or Argillisols. Wet desert
conditions, evidenced by burrows produced by invertebrate communities, and
tectonic activity, suggested by seismites, persist into the Early Jurassic Clarens
Formation.
Description
A dissertation presented to the Faculty of Science, University of the
Witwatersrand, in partial fulfillment of the requirements for the degree of Master
of Science.
August, 2017
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Citation
Clayton, Katherine Elisabeth, (2017) Stratigraphy and palaeoenvironments of the Carboniferous-Jurassic Karoo Supergroup in the Lebombo-Tshipise basin, University of the Witwatersrand, Johannesburg, https://hdl.handle.net/10539/24170