The seafloor character of the Roman Rock area in False Bay, South Africa
Andrew Terhorst
A
B
Abstract
This study investigates the seafloor character of a 12-km2 area off Simon’s Town in False Bay, South Africa.
The goal was to map the seafloor geology around Roman Rock Lighthouse, focusing on sedimentology.
Side-scan sonar and single-beam echosounder were used, complemented by sediment sampling and diver observations for ground-truthing. Sediment samples were analysed for texture and composition.
Six patterns of reflectivity (acoustic facies) were identified, including granite outcrops, wave ripples, and patches of gravelly and quartzose sands. Sediment analysis showed a mix of calcareous and quartzose components, with calcareous material dominating the gravel fraction near granite outcrops.
The Roman Rock seafloor reflects a complex depositional environment shaped by biogenic activity and wave-induced sediment transport.
This research lays the groundwork for future geological studies in False Bay, particularly around wave-induced sediment dynamics.
Keywords: diver observations, echosounder, False Bay, marine geology, Roman Rock, seafloor mapping, sedimentology, side-scan sonar, South Africa.
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