Browse by author
Lookup NU author(s): Dr Ian Boomer, Angharad Jones
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Holocene sediments of the north Norfolk coast (NNC) between Weybourne and Hunstanton have been studied using geophysical, sedimentological, biofacial and dating techniques. New cores and refraction seismic data have defined the topography of the pre-Holocene surface and show that the NNC sediment prism is underlain by an east-west trending Quaternary trough, probably a palaeo-river-valley. The age of the Holocene fill has been dated using radiocarbon and luminescence dates, while sedimentation rates were constrained by, and compared with, modern rates using radionuclide data. The Holocene sediments are divided into a sandy-barrier lithofacies association (LFA), and a muddy-silty-peat back-barrier LFA. The oldest Holocene sediments are peats, formed on an undulating till surface. These peats were forming by 11-10 cal. ka BP and continued to form until at least 7 cal. ka BP in a number of places. As Holocene sea-level rose, marine mudflat and saltmarsh environments began to form between 7 and 6 cal. ka BP east of Holkham and around 6 cal. ka BP or younger west of Holkham. A marked erosion surface between the barrier and back-barrier LFA in the Holkham to Burnham Overy area is imperfectly dated at <3 cal. ka BP, but suggests the sediment prism has thinned by about 3 km over 6 to c.3 cal. ka BP. This surface probably records the westward progress of laterally migrating tidal channels that caused back-barrier sediment erosion, along with shoreface processes, as sea-level rose. Small-scale regressive and transgressive saltmarsh sequences occur at different elevations along strike but cannot be correlated, suggesting that the control on saltmarsh and mudflat development is autocyclic rather than allocyclic. Generally, transgressive and regressive events are related to disposition of coastal barriers and these are superimposed on a general facies evolution governed by regional sea-level change. Predictions about how this barrier coastline might respond to increased rates of regional sea-level change caused by global warming, or climatic events like increased storminess, require an understanding of how specific segments of the coastline have responded over millennial time-scales. This longer-term evolution provides the baseline information for decision making and management strategy. It is likely that sandy sediment supply is limited on the NNC and this implies that the barriers will continue to move landward, probably at increased rates relative to today, suggesting that parts of the NNC will become more vulnerable to erosion and flooding.
Author(s): Andrews JE, Boomer I, Bailiff I, Balson P, Bristow C, Chroston PN, Funnell BM, Harwood GM, Jones R, Maher BA, Shimmield GB
Publication type: Article
Publication status: Published
Journal: Geological Society Special Publication
Year: 2000
Issue: 166
Pages: 219-251
Print publication date: 01/01/2000
ISSN (print): 0305-8719
ISSN (electronic): 2041-4927
Publisher: Geological Society Publishing House
URL: http://dx.doi.org/10.1144/GSL.SP.2000.166.01.12
DOI: 10.1144/GSL.SP.2000.166.01.12
Altmetrics provided by Altmetric
