Browsing by Author "Bamford, Marion K."

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    A fossil peat deposit from the Late Triassic (Carnian) of Zimbabwe with preserved cuticle of Pteridospermopsida and Ginkgoales, and its geological setting
    (BERNARD PRICE INSTITUTE FOR PALAEONTOLOGICAL RESEARCH, 2005) Barale, Georges; Bamford, Marion K.; Gomez, Bernard; Broderick, Timothy J.; Raath, Michael A.; Cadman, Ann
    Well-preserved cuticular material of Pteridospermopsida and Ginkgoales from the Late Triassic of Zimbabwe is described here for the first time. It is preserved within a brown peat-like lens in the Upper Karoo Angwa Sandstone Formation. The locality is on the Manyima River in the lower portion of the mid-Zambezi Valley of Zimbabwe. Using SEM and light microscopy to identify the taxa, the fragmentary cuticles are of Pteridospermopsida type and have been assigned to Lepidopteris sp. (Peltaspermales) and Dicroidium sp. A, B, (Corystospermales). Cuticles of the ginkgoalean leaf genus, Sphenobaiera, are also described. Well-preserved ovules were found in close association with the cuticles, but as the stomata are not visible they cannot be assigned to any genus. Based on their close similarity to the Dicroidium flora of the South African Upper Karoo, the plants are considered to be equivalent to the South African Molteno Formation in age (Carnian). The palynoflora supports this age bracket, as does fauna preserved nearby. The taphonomic process was one of transport, sorting and deposition in a fluvial system.
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    More fossil wood from the Namaqualand coast, South Africa; onshore material.
    (Bernard Price Institute for Palaeontological Research, 1995) Bamford, Marion K.; Corbett, Ian B.
    Fossil wood was collected from a palaeo-beach sequence on the farms Sandkop, Oubeep and adjacent State land, on the Namaqualand (west) coast of South Africa. Of the 14 samples sectioned only 5 were well enough preserved to describe and identify to species level. The woods are podocarpaceous and have been assigned to the taxa Podocarpoxylon cf. umzambense, Mesembrioxylon woburnense, M. stokesi and Mesembrioxylon sp. The samples are Lower Cretaceous in age and were most probably reworked a number of times into successively younger palaeoshoreline deposits. The same species occurred in the offshore sediments, therefore indicating a wider area of "woodland" and further evidence of extensive shelf erosion by subsequent marine transgressions and regressions.
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    Permo-Triassic palynology and palaeobotany of Zambia: a review
    (2016-03) Barbolini, Natasha; Bamford, Marion K.; Tolan, Stephen
    Permian and Triassic deposits in Zambia have been sporadically researched since the beginning of the 20th century, but there have not been many detailed works on the palaeobotany and palynology of these Karoo-aged rocks. Studies that have been published, suffered from a lack of inter-basinal correlation, which was also hampered by differing stratigraphic subdivisions. We review previous records of palynomorphs, megafloral remains and fossil wood in Zambian Permo-Triassic deposits, present a synthesis of micro- and macrofossil occurrences throughout the country, and propose a standardised subdivision for the Luangwa Valley. This will aid in future correlations between different Karoo basins and act as a framework for future palaeobotanical research in both Zambia and Gondwana.
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    Petroleum of the Deep: Palynological proxies for palaeoenvironment of deep offshore upper Miocene-Pliocene sediments from Niger Delta, Nigeria
    (2016-03) Olayiwola, Moshood A.; Bamford, Marion K.
    Better understanding of the palaeoenvironments under which the lithologies of the deepwater petroleum systems were deposited is necessary to unravel the problem surrounding the deep offshore petroleum exploration and production. Therefore, the integration of palynological, lithological and gamma ray log data of ditch-cutting samples from wells A and B from the Niger Delta region are utilized to delineate the upper Miocene-Pliocene depositional environments. The detailed palynological analysis revealed diverse and abundant palynomorph assemblages, which consisted of angiosperm pollen 85.7 %, monolete spores 5 %, fungal elements 4 %, trilete fern spores 4 %, freshwater algae 1 % and marine elements 0.3 %. Eight informal palynological assemblage zones (PAZ I-PAZ VIII) with corresponding eustatic sea level changes are delineated in Wells A and B. Four lithofacies, namely sandstones, siltstones, claystones and mudstones, are recognized in association with three depositional environments in the studied wells. Distributary channels are characterized by the erosive base and filled with moderate to fine, uniform and blocky sand-grain size sediments that are of good reservoir quality. Mud-rich sediments, which are of excellent sealing rock potential, capped this sand formation. Moreover, tidal channels are typified by the erosive base and filled with fining-upwards sand sequences with tops covered by muddy sediments. Finally, the regressive barrier sands are filled by coarsening-upwards sediments with basal organic-rich deposits that are likely to be good quality source rock. The oil potential of these sites is of interest to the oil company and the reconstructed palaeoenvironments will be useful for deepwater exploration and exploitation, and probably remove or minimize the risks that are commonly involved in this task.
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    Proceedings of the 2017 biennial conference of the South African Society of Quaternary Research
    (2017-04) Fitchett, Jennifer M.; Bamford, Marion K.
    Proceedings of the 21st Biennial Conference of the South African Society of Quaternary Research, Johannesburg, 3–7 April 2017