Age frequency distribution and revised stable isotope curves for New Zealand speleothems: palaeoclimatic implications
The occurrence of speleothems in New Zealand with reversed magnetism indicates that secondary calcite deposition in caves has occurred for more than 780 thousand years (ka). 394 uranium-series dates on 148 speleothems show that such deposition has taken place somewhere in the country with little int...
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ftdoajarticles:oai:doaj.org/article:70619802cabe4650a5d5acd8da4facb0 2023-05-15T13:58:44+02:00 Age frequency distribution and revised stable isotope curves for New Zealand speleothems: palaeoclimatic implications Williams Paul W. Neil Helen L. Zhao Jian-Xin 2010-07-01T00:00:00Z https://doaj.org/article/70619802cabe4650a5d5acd8da4facb0 EN eng University of South Florida Libraries http://www.ijs.speleo.it/pdf/73.600.39(2)_Williams.et.al.pdf https://doaj.org/toc/0392-6672 https://doaj.org/toc/1827-806X 0392-6672 1827-806X https://doaj.org/article/70619802cabe4650a5d5acd8da4facb0 International Journal of Speleology, Vol 39, Iss 2, Pp 99-112 (2010) speleothems New Zealand palaeoclimate stable isotopes uranium series Biology (General) QH301-705.5 Geology QE1-996.5 article 2010 ftdoajarticles 2022-12-31T06:46:34Z The occurrence of speleothems in New Zealand with reversed magnetism indicates that secondary calcite deposition in caves has occurred for more than 780 thousand years (ka). 394 uranium-series dates on 148 speleothems show that such deposition has taken place somewhere in the country with little interruption for more than 500 ka. A relative probability distribution of speleothem ages indicates that most growth occurred in mild, moist interglacial and interstadial intervals, a conclusion reinforced by comparing peaks and troughs in the distribution with time series curves of speleothem δ18O and δ13C values. The stable isotope time series were constructed using data from 15 speleothems from two different regions of the country. The greater the number of overlapping speleothem series (i.e. the greater the sample depth) for any one region, the more confidence is justified in considering the stacked record to be representative of the region. Revising and extending earlier work, composite records are produced for central-west North Island (CWNI) and north-west South Island (NWSI). Both demonstrate that over the last 15 ka the regions responded similarly to global climatic events, but that the North Island site was also influenced by the waxing and waning of regional subtropical marine influences that penetrated from the north but did not reach the higher latitudes of the South Island. Cooling marking the commencement of the last glacial maximum (LGM) was evident from about 28 ka. There was a mid-LGM interstadial at 23-21.7 ka and Termination 1 occurred around 18.1 ka. The glacial-interglacial transition was marked by a series of negative excursions in δ18O that coincide with dated recessional moraines in South Island glaciers. A late glacial cooling event, the NZ Late Glacial Reversal, occurred from 13.4-11.2 ka and this was followed by an early Holocene optimum at 10.8 ka. Comparison of δ18O records from NWSI and EPICA DML ice-core shows climatic events in New Zealand to lag those in Antarctica by several centuries ... Article in Journal/Newspaper Antarc* Antarctica DML EPICA ice core Directory of Open Access Journals: DOAJ Articles New Zealand |
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Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
speleothems New Zealand palaeoclimate stable isotopes uranium series Biology (General) QH301-705.5 Geology QE1-996.5 |
spellingShingle |
speleothems New Zealand palaeoclimate stable isotopes uranium series Biology (General) QH301-705.5 Geology QE1-996.5 Williams Paul W. Neil Helen L. Zhao Jian-Xin Age frequency distribution and revised stable isotope curves for New Zealand speleothems: palaeoclimatic implications |
topic_facet |
speleothems New Zealand palaeoclimate stable isotopes uranium series Biology (General) QH301-705.5 Geology QE1-996.5 |
description |
The occurrence of speleothems in New Zealand with reversed magnetism indicates that secondary calcite deposition in caves has occurred for more than 780 thousand years (ka). 394 uranium-series dates on 148 speleothems show that such deposition has taken place somewhere in the country with little interruption for more than 500 ka. A relative probability distribution of speleothem ages indicates that most growth occurred in mild, moist interglacial and interstadial intervals, a conclusion reinforced by comparing peaks and troughs in the distribution with time series curves of speleothem δ18O and δ13C values. The stable isotope time series were constructed using data from 15 speleothems from two different regions of the country. The greater the number of overlapping speleothem series (i.e. the greater the sample depth) for any one region, the more confidence is justified in considering the stacked record to be representative of the region. Revising and extending earlier work, composite records are produced for central-west North Island (CWNI) and north-west South Island (NWSI). Both demonstrate that over the last 15 ka the regions responded similarly to global climatic events, but that the North Island site was also influenced by the waxing and waning of regional subtropical marine influences that penetrated from the north but did not reach the higher latitudes of the South Island. Cooling marking the commencement of the last glacial maximum (LGM) was evident from about 28 ka. There was a mid-LGM interstadial at 23-21.7 ka and Termination 1 occurred around 18.1 ka. The glacial-interglacial transition was marked by a series of negative excursions in δ18O that coincide with dated recessional moraines in South Island glaciers. A late glacial cooling event, the NZ Late Glacial Reversal, occurred from 13.4-11.2 ka and this was followed by an early Holocene optimum at 10.8 ka. Comparison of δ18O records from NWSI and EPICA DML ice-core shows climatic events in New Zealand to lag those in Antarctica by several centuries ... |
format |
Article in Journal/Newspaper |
author |
Williams Paul W. Neil Helen L. Zhao Jian-Xin |
author_facet |
Williams Paul W. Neil Helen L. Zhao Jian-Xin |
author_sort |
Williams Paul W. |
title |
Age frequency distribution and revised stable isotope curves for New Zealand speleothems: palaeoclimatic implications |
title_short |
Age frequency distribution and revised stable isotope curves for New Zealand speleothems: palaeoclimatic implications |
title_full |
Age frequency distribution and revised stable isotope curves for New Zealand speleothems: palaeoclimatic implications |
title_fullStr |
Age frequency distribution and revised stable isotope curves for New Zealand speleothems: palaeoclimatic implications |
title_full_unstemmed |
Age frequency distribution and revised stable isotope curves for New Zealand speleothems: palaeoclimatic implications |
title_sort |
age frequency distribution and revised stable isotope curves for new zealand speleothems: palaeoclimatic implications |
publisher |
University of South Florida Libraries |
publishDate |
2010 |
url |
https://doaj.org/article/70619802cabe4650a5d5acd8da4facb0 |
geographic |
New Zealand |
geographic_facet |
New Zealand |
genre |
Antarc* Antarctica DML EPICA ice core |
genre_facet |
Antarc* Antarctica DML EPICA ice core |
op_source |
International Journal of Speleology, Vol 39, Iss 2, Pp 99-112 (2010) |
op_relation |
http://www.ijs.speleo.it/pdf/73.600.39(2)_Williams.et.al.pdf https://doaj.org/toc/0392-6672 https://doaj.org/toc/1827-806X 0392-6672 1827-806X https://doaj.org/article/70619802cabe4650a5d5acd8da4facb0 |
_version_ |
1766267078105366528 |