Modern beachrock formation in Durban, KwaZulu-Natal

South African Journal of Science

 
 
Field Value
 
Title Modern beachrock formation in Durban, KwaZulu-Natal
 
Creator Cawthra, Hayley Uken, Ron
 
Subject Geology modern beachrock formation; carbonate cementation; marine phreatic diagenesis; recent sea level change; clastic shoreline
Description We explored the recent cementation of modern beachrock on the seaward margin of the Durban Bluff, central KwaZulu-Natal. The low latitude and subtropical climatic setting is a unique context compared to the more commonly documented contemporary beachrock formation in the tropics. Geological field mapping was carried out and here we present results based on sedimentary facies of a clastic shoreline and carbonate diagenesis of interstitial cements using transmitted light microscopy. The beachrock was cemented by micrite and aragonite, and iron oxide infilled voids. The presence of human artefacts within the deposit showed evidence for cementation within the last century. The elevation (at Mean Low Water) and correlation to rates of sea level change for the east coast of South Africa showed that the beachrock is less than 72 years in age. In contrast to older local Pleistocene deposits, beachrocks have cemented along this stretch of coast during successive sea level highstands with similar climatic regimes – the last Interglacial, the Holocene High and the present. Here we report the most southerly documentation of modern beachrock in KwaZulu-Natal, which, to our knowledge, represents the youngest deposit reported in southern Africa.
 
Publisher AOSIS
 
Contributor Council for Geoscience
Date 2012-07-11
 
Type info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion — Geological mapping; laboratory work
Format application/pdf text/html application/epub+zip text/xml
Identifier 10.4102/sajs.v108i7/8.935
 
Source South African Journal of Science; Vol 108, No 7/8 (2012); 5 Pages 1996-7489 0038-2353
 
Language eng
 
Relation
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https://journals.sajs.aosis.co.za/index.php/sajs/article/view/935/1304 https://journals.sajs.aosis.co.za/index.php/sajs/article/view/935/1305 https://journals.sajs.aosis.co.za/index.php/sajs/article/view/935/1331 https://journals.sajs.aosis.co.za/index.php/sajs/article/view/935/1307 https://journals.sajs.aosis.co.za/index.php/sajs/article/downloadSuppFile/935/3939 https://journals.sajs.aosis.co.za/index.php/sajs/article/downloadSuppFile/935/3940 https://journals.sajs.aosis.co.za/index.php/sajs/article/downloadSuppFile/935/3941
 
Coverage KwaZulu-Natal coast; Durban Bluff; littoral zone Quaternary Period Beachrock formation; carbonate diagenesis
Rights Copyright (c) 2012 Hayley Cawthra, Ron Uken https://creativecommons.org/licenses/by/4.0
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