eprintid: 10082046
rev_number: 25
eprint_status: archive
userid: 608
dir: disk0/10/08/20/46
datestamp: 2019-09-25 13:16:00
lastmod: 2021-10-14 22:32:42
status_changed: 2019-09-25 13:16:00
type: article
metadata_visibility: show
creators_name: Knight, J
creators_name: Burningham, H
title: Bedrock hardness values and morphological zonation of a shore platform in South Africa
ispublished: pub
divisions: UCL
divisions: B03
divisions: C03
divisions: F26
keywords: intertidal platform, micromorphology, rock surface hardness, wave-splash, weathering, wetting/drying
note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions.
abstract: Shore platforms found along rock coasts worldwide are often interpreted as wave abrasion acting on uniform bedrock surfaces. Whilst this viewpoint may apply at the macroscale, there are complex feedbacks among bedrock properties (rock type, mineralogy, rock structures), weathering and erosion processes and rates, and microtopography at the meso- to microscale. In turn, these influence wave runup, backwash processes, and the extent of wave-splash and physical, chemical, and biological weathering processes that result. This study investigates the relationships among bedrock hardness properties, microtopography, and shore platform denudation processes from a site on the Indian Ocean-facing coast of South Africa. Three shore-normal transects (45–57 m in length) were surveyed across the sandstone platform using a differential global positioning system (GPS). These data were integrated with rock surface hardness measurements along the transects taken using a Proceq Equotip instrument. Results show that platform morphology and hardness values vary considerably, corresponding to the most dominant denudation processes found at different positions in the tidal frame. The lowest hardness values (most extensive rock weathering) are found on the landward third of the platform but away from the land margin. The highest and greatest variability of hardness values are found on bedrock highs immediately above the highest astronomical tide level, in the lower third of the profile. This position suggests a dominant role of wave-splash and wetting/drying. Variations in hardness values and microtopography through the transects were used to develop an evolutionary model linking rock hardness values to specific weathering and erosion processes of the rocky shore platform.
date: 2020
date_type: published
publisher: Taylor & Francis
official_url: https://doi.org/10.1080/0035919X.2019.1670751
oa_status: green
full_text_type: other
language: eng
primo: open
primo_central: open_green
verified: verified_manual
elements_id: 1696115
doi: 10.1080/0035919X.2019.1670751
lyricists_name: Burningham, Helene
lyricists_id: HBURN48
actors_name: Burningham, Helene
actors_id: HBURN48
actors_role: owner
full_text_status: public
publication: Transactions of the Royal Society of South Africa
volume: 75
number: 1
pagerange: 40-53
issn: 0035-919X
citation:        Knight, J;    Burningham, H;      (2020)    Bedrock hardness values and morphological zonation of a shore platform in South Africa.                   Transactions of the Royal Society of South Africa , 75  (1)   pp. 40-53.    10.1080/0035919X.2019.1670751 <https://doi.org/10.1080/0035919X.2019.1670751>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/10082046/1/TTRS-2019-0041.R1_Proof_hi-1.pdf