Determining Holocene sea-level changes on an exposed coastline: a case study of the Coffs Harbour area mid-north NSW
The mid to late Holocene sea-level history of the Australian region provokes intense ongoing debate. Has the sea-level been static to smoothly falling or was it characterised by rapid fluctuations, possibly containing a eustatic signal? A range of evidence types has been utilised by researchers, on...
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ftunivnewengland:oai:rune.une.edu.au:1959.11/8780 2023-08-27T04:08:46+02:00 Determining Holocene sea-level changes on an exposed coastline: a case study of the Coffs Harbour area mid-north NSW Smedley, Glenn Baker, Robert G School of Psychology and Behavioural Science 2010 https://hdl.handle.net/1959.11/8780 en eng Australasian Quaternary Association Inc https://hdl.handle.net/1959.11/8780 une:8970 http://aqua.org.au/AQUA/attachments/AQUA2010prog.pdf Quaternary Environments Conference Publication 2010 ftunivnewengland 2023-08-10T19:33:41Z The mid to late Holocene sea-level history of the Australian region provokes intense ongoing debate. Has the sea-level been static to smoothly falling or was it characterised by rapid fluctuations, possibly containing a eustatic signal? A range of evidence types has been utilised by researchers, on all sides of this debate, to establish, develop and provide evidence for their positions. In this study, the relic crusts of the tubeworm 'Galeolaria caespitosa', a fixed intertidal biological indicator (FIBI), have been sought out, surveyed and radiocarbon dated. 'G. caespitosa' has a limited growth range in the intertidal zone and when the vertical difference between the relic crusts and current 'G. caespitosa' is measured a sea-level variation with a small vertical error can be established. The sites described in this study are from the Coffs Harbour area of the NSW mid north coast. Three sites were identified; the first on Mutton Bird Island, the second on Coffs Harbour's southern headland and a third on Sawtell's northern headland. Relic crusts were surveyed and samples removed and dated from two levels on Mutton Bird Island and single levels at the other two sites. Six samples in total were dated with the higher site at Mutton Bird Island yielding two samples ~2.0m above current 'G. caespitosa' with ages of 3875 Cal. yr BP and 3626 Cal. yr BP (Midpoints of age range). A sample from the southern headland of Coffs Harbour was elevated 1.60m above current 'G. caespitosa' and yielded an age of 3509 Cal. yr BP. The lower site on Mutton Bird Island contained two discrete relic crusts of 'G. caespitosa', with horizontal separation of 1.0m, 1.44m above current crevice 'G. caespitosa'. The most northerly crust was dated at 1590 Cal. yr BP and the southerly at 1845 Cal. yr BP. The sample from the Sawtell site was dated at 2535 Cal. yr BP and was 1.75m above the highest current living crevice 'G. caespitosa'. Some characteristics of the sea-level history in this area are suggested by the nature of these relic crusts. ... Conference Object Bird Island Research UNE - University of New England at Armidale, NSW Australia Bird Island ENVELOPE(-38.060,-38.060,-54.004,-54.004) Mutton ENVELOPE(-65.652,-65.652,-66.008,-66.008) |
institution |
Open Polar |
collection |
Research UNE - University of New England at Armidale, NSW Australia |
op_collection_id |
ftunivnewengland |
language |
English |
topic |
Quaternary Environments |
spellingShingle |
Quaternary Environments Smedley, Glenn Baker, Robert G School of Psychology and Behavioural Science Determining Holocene sea-level changes on an exposed coastline: a case study of the Coffs Harbour area mid-north NSW |
topic_facet |
Quaternary Environments |
description |
The mid to late Holocene sea-level history of the Australian region provokes intense ongoing debate. Has the sea-level been static to smoothly falling or was it characterised by rapid fluctuations, possibly containing a eustatic signal? A range of evidence types has been utilised by researchers, on all sides of this debate, to establish, develop and provide evidence for their positions. In this study, the relic crusts of the tubeworm 'Galeolaria caespitosa', a fixed intertidal biological indicator (FIBI), have been sought out, surveyed and radiocarbon dated. 'G. caespitosa' has a limited growth range in the intertidal zone and when the vertical difference between the relic crusts and current 'G. caespitosa' is measured a sea-level variation with a small vertical error can be established. The sites described in this study are from the Coffs Harbour area of the NSW mid north coast. Three sites were identified; the first on Mutton Bird Island, the second on Coffs Harbour's southern headland and a third on Sawtell's northern headland. Relic crusts were surveyed and samples removed and dated from two levels on Mutton Bird Island and single levels at the other two sites. Six samples in total were dated with the higher site at Mutton Bird Island yielding two samples ~2.0m above current 'G. caespitosa' with ages of 3875 Cal. yr BP and 3626 Cal. yr BP (Midpoints of age range). A sample from the southern headland of Coffs Harbour was elevated 1.60m above current 'G. caespitosa' and yielded an age of 3509 Cal. yr BP. The lower site on Mutton Bird Island contained two discrete relic crusts of 'G. caespitosa', with horizontal separation of 1.0m, 1.44m above current crevice 'G. caespitosa'. The most northerly crust was dated at 1590 Cal. yr BP and the southerly at 1845 Cal. yr BP. The sample from the Sawtell site was dated at 2535 Cal. yr BP and was 1.75m above the highest current living crevice 'G. caespitosa'. Some characteristics of the sea-level history in this area are suggested by the nature of these relic crusts. ... |
format |
Conference Object |
author |
Smedley, Glenn Baker, Robert G School of Psychology and Behavioural Science |
author_facet |
Smedley, Glenn Baker, Robert G School of Psychology and Behavioural Science |
author_sort |
Smedley, Glenn |
title |
Determining Holocene sea-level changes on an exposed coastline: a case study of the Coffs Harbour area mid-north NSW |
title_short |
Determining Holocene sea-level changes on an exposed coastline: a case study of the Coffs Harbour area mid-north NSW |
title_full |
Determining Holocene sea-level changes on an exposed coastline: a case study of the Coffs Harbour area mid-north NSW |
title_fullStr |
Determining Holocene sea-level changes on an exposed coastline: a case study of the Coffs Harbour area mid-north NSW |
title_full_unstemmed |
Determining Holocene sea-level changes on an exposed coastline: a case study of the Coffs Harbour area mid-north NSW |
title_sort |
determining holocene sea-level changes on an exposed coastline: a case study of the coffs harbour area mid-north nsw |
publisher |
Australasian Quaternary Association Inc |
publishDate |
2010 |
url |
https://hdl.handle.net/1959.11/8780 |
long_lat |
ENVELOPE(-38.060,-38.060,-54.004,-54.004) ENVELOPE(-65.652,-65.652,-66.008,-66.008) |
geographic |
Bird Island Mutton |
geographic_facet |
Bird Island Mutton |
genre |
Bird Island |
genre_facet |
Bird Island |
op_source |
http://aqua.org.au/AQUA/attachments/AQUA2010prog.pdf |
op_relation |
https://hdl.handle.net/1959.11/8780 une:8970 |
_version_ |
1775349646255718400 |