ABSTRACT
This study deals with the physical aspects of sedimentation in
Saldanha Bay and Langebaan Lagoon. On the basis of detailed textural investigations
the depositional history of the study area has been established.
The sediments in the bay and in the lagoon consist of a fine terrigenous
quartz population and a coarser skeletal carbonate population, which have been
mixed in various proportions. In order to gain size parameters that are more
closely related to the hydraulic nature of depositional processes observed in
the marine environment, grain size analyses were performed with an automatically
recording settling tube system. The instrument was developed in the
course of this study. Construction costs were kept extremely low without,
·however, impairing the scientific requirements of the instrument~
Over 500 sediment samples were recovered on a closely- spaced grid;
in each case, a size analysis was performed on the total sample and on the
insoluble, terrigenous fraction. By subtracting the terrigenous size distribution
from that of the total sediment, the relevant size parameters of the
bioclastic component were calculated. In this manner 1500 individual size :
distributions were avaible for interpretation.
In Saldanha Bay, a number of distinct energy zones can be ?istinguished
which are clearly related to the wave-refraction pattern. A centrally-exposed
zone is lined on both sides by semi-exposed zones, which in turn are followed
by a sheltered zone in the northen bay and a lagoon/bay transitional zone in
the south. The transitional zone is characterized by the interaction of
ocean-waves and tidal ebb-currents leaving the lagoonal system via the outflow
channels that are situated in the southern, wave-sheltered part of Saldanha Bay.
Physiographically the bay consists of a narrow, inshore sand prism
that merges with thicker sand bodies that have accumulated in the northen,
sheltered parts of the bay and in the bay/lagoon transitional zone, where a
tidal delta is well defined. Both semi-exposed zones are covered by a thin
veneer of sediment, usually under 0,5m thick. In the centrally-eA-posed parts
of the bay an extensive abrasion platform.is observed. It stretches between
the inshore sand prism, which terminates approximately along the llm depth
contour, and the onset of the South Channel sand sheet at about -15m •
FLEMMING, B (2021). Depositional Processes In Saldanha Bay And Langebaan Lagoon. Afribary. Retrieved from https://tracking.afribary.com/works/depositional-processes-in-saldanha-bay-and-langebaan-lagoon
FLEMMING, B.W. "Depositional Processes In Saldanha Bay And Langebaan Lagoon" Afribary. Afribary, 15 May. 2021, https://tracking.afribary.com/works/depositional-processes-in-saldanha-bay-and-langebaan-lagoon. Accessed 18 Dec. 2024.
FLEMMING, B.W. . "Depositional Processes In Saldanha Bay And Langebaan Lagoon". Afribary, Afribary, 15 May. 2021. Web. 18 Dec. 2024. < https://tracking.afribary.com/works/depositional-processes-in-saldanha-bay-and-langebaan-lagoon >.
FLEMMING, B.W. . "Depositional Processes In Saldanha Bay And Langebaan Lagoon" Afribary (2021). Accessed December 18, 2024. https://tracking.afribary.com/works/depositional-processes-in-saldanha-bay-and-langebaan-lagoon