Waterford Formation in the south-eastern Karoo : implications for basin development : research letter
0
Citation
0
Reference
20
Related Paper
Abstract:
Extensive research on the rocks of the Karoo Supergroup has shown that this sequence, which contains an unsurpassed record of Permian-Jurassic tetrapods, records a largely unbroken stratigraphic succession from 300 Ma to 180 Ma. This Gondwanan succession was deposited in a changing environmental setting reflecting glacial marine through deltaic to fluvial and aeolian desert conditions. The contact between the Ecca and Beaufort Groups (at the top of the Waterford Formation of the Ecca Group) in the southern and western Karoo represents a change in depositional environment from a subaqueous to a subaerial delta plain. By contrast, the Waterford Formation has not yet been recognised in the south-eastern Karoo Basin, which might imply that a major unconformity is present between the Fort Brown Formation of the Ecca Group, deposited in a prodelta environment, and the overlying fluvially deposited Koonap Formation of the Beaufort Group. From careful documentation of lithofacies and sedimentological data, it can be demonstrated that the Waterford Formation is indeed present in the south-eastern part of the basin and that no major unconformity is present - a fact that has implications for the mapping of Karoo rocks in the Eastern Cape Province of South Africa, for understanding the depositional environment of 'reptilian' fossils from the lowermost Beaufort in this part of the Karoo basin, and for basin development models.Keywords:
Beaufort scale
Subaerial
Supergroup
Cite
Published records on the palaeontology of the Lower Jurassic Lisbon Formation in the Ellisras Basin (a South African continuation of the Botswana Kalahari Karoo Basin) are virtually non-existent. Here we review the geology of this extremely poorly exposed unit, and describe a newly discovered ichnofossil and fossil vertebrate association, consisting of constructed structures resembling termitaria as well as of basal sauropodomorph remains. Our paleontological and sedimentological analyses permit a direct bioand lithostratigraphic correlation of the Lisbon Formation at farm Lisbon with the upper part of the Elliot Formation in the main Karoo Basin as well as other Lower Jurassic continental red bed successions throughout southern Africa. We tentatively suggest that the formation (especially its upper part) was deposited in a dryland setting with well-drained soils that at least episodically supported some flora and a fauna probably dominated by basal sauropodomorphs.
Supergroup
Cite
Citations (7)
Palaeogeography
Cite
Citations (1)
Carpentaria
Palaeogeography
Dolostone
Cite
Citations (10)
Supercontinent
Devonian
Cite
Citations (35)
Continental Margin
Oceanic basin
Cite
Citations (205)
Research Article| June 01, 2015 TERRESTRIAL VERTEBRATE COLONISATION AND THE ECCA-BEAUFORT BOUNDARY IN THE SOUTHEASTERN MAIN KAROO BASIN, SOUTH AFRICA: IMPLICATIONS FOR PERMIAN BASIN EVOLUTION R. MASON; R. MASON Evolutionary Studies Institute, School of Geosciences, University of the Witwatersrand, P.O. Wits, Johannesburg, 2050, South Africa, e-mail: richard_m@vodamail.co.za; bruce.rubidge@wits.ac.za; jhancox@cciconline.com Search for other works by this author on: GSW Google Scholar B. RUBIDGE; B. RUBIDGE Evolutionary Studies Institute, School of Geosciences, University of the Witwatersrand, P.O. Wits, Johannesburg, 2050, South Africa, e-mail: richard_m@vodamail.co.za; bruce.rubidge@wits.ac.za; jhancox@cciconline.com Search for other works by this author on: GSW Google Scholar J. HANCOX J. HANCOX Evolutionary Studies Institute, School of Geosciences, University of the Witwatersrand, P.O. Wits, Johannesburg, 2050, South Africa, e-mail: richard_m@vodamail.co.za; bruce.rubidge@wits.ac.za; jhancox@cciconline.com Search for other works by this author on: GSW Google Scholar South African Journal of Geology (2015) 118 (2): 145–156. https://doi.org/10.2113/gssajg.118.2.145 Article history first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation R. MASON, B. RUBIDGE, J. HANCOX; TERRESTRIAL VERTEBRATE COLONISATION AND THE ECCA-BEAUFORT BOUNDARY IN THE SOUTHEASTERN MAIN KAROO BASIN, SOUTH AFRICA: IMPLICATIONS FOR PERMIAN BASIN EVOLUTION. South African Journal of Geology 2015;; 118 (2): 145–156. doi: https://doi.org/10.2113/gssajg.118.2.145 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietySouth African Journal of Geology Search Advanced Search Abstract Rocks of the Late Carboniferous to Early Jurassic aged Karoo Supergroup of South Africa preserve a sedimentary succession, deposited in a retro-arc foreland setting. This succession documents environmental change from glacial-marine, through full marine to continental fluvial and aeolian environments, culminating in rift associated continental flood basalt extrusions. The Karoo Basin is internationally renowned for its wealth of fossil tetrapods, enabling the establishment of a reliable and useful biostratigraphic framework which has international applicability for correlation of Permian-Triassic tetrapod-bearing continental deposits. The transition from marine to continental deposition in the Karoo has been the subject of much recent research, particularly in regard to the position of the Ecca-Beaufort contact. Our study indicates for the first time that in the south-eastern part of the basin, as for the rest of the basin, this transition comprises three separate facies associations deposited respectively in the prodelta, subaqueous delta plain and subaerial delta plain environments. The Tapinocephalus Assemblage Zone is the lowermost vertebrate biozone in the Koonap Formation indicating that the Ecca-Beaufort boundary is diachronous in the southern part of the basin, younging towards the east. This supports the easterly to northeasterly prograding shoreline model previously proposed for the Ecca-Beaufort transition and provides new insight on the distribution of the earliest land-living vertebrates in the south-eastern Karoo Basin. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
Beaufort scale
Cite
Citations (4)
Cite
Citations (229)
Basement
Syncline
Cite
Citations (26)
Diamictite
Cite
Citations (51)