Reinterpreting vintage geophysical data from the Algoa and Gamtoos Basins, South Africa: an integrated sequence stratigraphic framework since the middle Mesozoic
type: CreativeWork
description: Sequence stratigraphy is a branch of stratigraphy that is concerned with how genetically related geological successions are deposited in time and space. This requires the integration of diverse types of datasets (drill core, outcrop, wireline, reflection seismic surveys, etc.) to build robust depositional models, the cornerstones of stratigraphic frameworks. Although the application of sequence stratigraphy has been a successful tool to predict the lithology of geobodies in the petroleum industry, terminology is inconsistently used by the different schools of thought to define stratigraphic surfaces. This has resulted in multiple sequence stratigraphic models that interpret the same data differently. The limited exploration, to-date, and poor dataset quality have impeded the understanding of the geological evolution of the offshore Algoa and Gamtoos Basins in the southern Cape region of South Africa. To reconstruct the main geological events in the area since the late Early Jurassic, we integrated vintage borehole and seismic data as well as key outcrop observations, generated contemporary gross depositional environment models for the basin fill, and tested the applicability of different sequence stratigraphic models. The studied stratigraphic interval formed since the inception of Gondwana break-up, in syn- and post-rift systems that were increasingly dominated by marine processes, especially in the distal hanging walls. Marine incursions are detected in the Upper and Middle Jurassic in the Algoa and Gamtoos Basins, respectively. However, the severely eroded Algoa Basin syn-rift succession, exacerbated by poor data quality, makes it challenging to understand the timing of the marine incursion in this compartmentalized half-graben. Sedimentation within these half-grabens primarily occurred above the hanging walls, whilst the footwalls (i.e., basement highs) formed the dominant sediment source areas. The geological characteristics of the studied synrift succession pr…
abstract: Sequence stratigraphy is a branch of stratigraphy that is concerned with how genetically related geological successions are deposited in time and space. This requires the integration of diverse types of datasets (drill core, outcrop, wireline, reflection seismic surveys, etc.) to build robust depositional models, the cornerstones of stratigraphic frameworks. Although the application of sequence stratigraphy has been a successful tool to predict the lithology of geobodies in the petroleum industry, terminology is inconsistently used by the different schools of thought to define stratigraphic surfaces. This has resulted in multiple sequence stratigraphic models that interpret the same data differently. The limited exploration, to-date, and poor dataset quality have impeded the understanding of the geological evolution of the offshore Algoa and Gamtoos Basins in the southern Cape region of South Africa. To reconstruct the main geological events in the area since the late Early Jurassic, we integrated vintage borehole and seismic data as well as key outcrop observations, generated contemporary gross depositional environment models for the basin fill, and tested the applicability of different sequence stratigraphic models. The studied stratigraphic interval formed since the inception of Gondwana break-up, in syn- and post-rift systems that were increasingly dominated by marine processes, especially in the distal hanging walls. Marine incursions are detected in the Upper and Middle Jurassic in the Algoa and Gamtoos Basins, respectively. However, the severely eroded Algoa Basin syn-rift succession, exacerbated by poor data quality, makes it challenging to understand the timing of the marine incursion in this compartmentalized half-graben. Sedimentation within these half-grabens primarily occurred above the hanging walls, whilst the footwalls (i.e., basement highs) formed the dominant sediment source areas. The geological characteristics of the studied synrift succession pr…
author: Makhubele, Marvel Hope
keywords: geological sciences
date published: 2021
date modified: 2026-07-22T22:22:43Z
provider: University of Cape Town
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Department of Geological Sciences

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property ID: Handle
value: http://hdl.handle.net/11427/35838