Detailed palaeomagnetic record at Rose Cottage Cave, South Africa: Implications for the Holocene geomagnetic field behaviour and chronostratigraphy
Palaeomagnetic data from a sedimentary section spanning the Holocene and terminal Pleistocene (~13 kya) from Rose Cottage Cave, eastern Free State (South Africa), are reported. The palaeomagnetic analysis took into account rock magnetism and directional analysis. The former reveals that most samples...
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ftdoajarticles:oai:doaj.org/article:da4f4a1a940c482e8b5e1b9581051a48 2023-05-15T16:19:40+02:00 Detailed palaeomagnetic record at Rose Cottage Cave, South Africa: Implications for the Holocene geomagnetic field behaviour and chronostratigraphy Hugo G. Nami Carlos A. Vasquez Lyn Wadley Paloma de la Peña 2020-01-01T00:00:00Z https://doi.org/10.17159/sajs.2020/6550 https://doaj.org/article/da4f4a1a940c482e8b5e1b9581051a48 EN eng Academy of Science of South Africa https://www.sajs.co.za/article/view/6550 https://doaj.org/toc/1996-7489 doi:10.17159/sajs.2020/6550 1996-7489 https://doaj.org/article/da4f4a1a940c482e8b5e1b9581051a48 South African Journal of Science, Vol 116, Iss 1/2 (2020) palaeomagnetism rock magnetism remanent magnetisation palaeosecular variations virtual geomagnetic pole positions Science Q Science (General) Q1-390 Social Sciences H Social sciences (General) H1-99 article 2020 ftdoajarticles https://doi.org/10.17159/sajs.2020/6550 2022-12-31T08:12:51Z Palaeomagnetic data from a sedimentary section spanning the Holocene and terminal Pleistocene (~13 kya) from Rose Cottage Cave, eastern Free State (South Africa), are reported. The palaeomagnetic analysis took into account rock magnetism and directional analysis. The former reveals that most samples show stable single domain and superparamagnetic particles of Ti-poor magnetite and haematite. Natural remanent magnetisation directions were determined by progressive alternating field demagnetisation methodology. Directional analysis shows normal directions between samples 18 to 39 and 85 to 92; however, during the Early and Late Holocene in samples principally from RC40 to 84 ‘anomalous’ directions occurred. There is a significant westward shift in declination of ~80°, and a conspicuous fluctuating inclination in the lower part of the section during the Early Holocene at ≥9.5 kya and before ~12.0/13.0 kya. This palaeomagnetic record might become a chronostratigraphical marker for latest Pleistocene/Holocene sedimentary deposits in South Africa. Our two new accelerator mass spectrometry radiocarbon dates for the sampled deposit are 9500±50 BP and 1115±30 BP. Significance • The study provides new accelerator mass spectrometry dates on the chronological sequence existing in Rose Cottage Cave. • The findings contribute to the knowledge of the geomagnetic field behaviour since the terminal Pleistocene to the Late Holocene in a period spanning the last 13 000/12 000 years. • This palaeomagnetic record might become a chronostratigraphical marker for the latest Pleistocene/ Holocene sedimentary deposits in South Africa. Article in Journal/Newspaper Geomagnetic Pole Directory of Open Access Journals: DOAJ Articles Kya ENVELOPE(8.308,8.308,63.772,63.772) South African Journal of Science 116 1/2 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
palaeomagnetism rock magnetism remanent magnetisation palaeosecular variations virtual geomagnetic pole positions Science Q Science (General) Q1-390 Social Sciences H Social sciences (General) H1-99 |
spellingShingle |
palaeomagnetism rock magnetism remanent magnetisation palaeosecular variations virtual geomagnetic pole positions Science Q Science (General) Q1-390 Social Sciences H Social sciences (General) H1-99 Hugo G. Nami Carlos A. Vasquez Lyn Wadley Paloma de la Peña Detailed palaeomagnetic record at Rose Cottage Cave, South Africa: Implications for the Holocene geomagnetic field behaviour and chronostratigraphy |
topic_facet |
palaeomagnetism rock magnetism remanent magnetisation palaeosecular variations virtual geomagnetic pole positions Science Q Science (General) Q1-390 Social Sciences H Social sciences (General) H1-99 |
description |
Palaeomagnetic data from a sedimentary section spanning the Holocene and terminal Pleistocene (~13 kya) from Rose Cottage Cave, eastern Free State (South Africa), are reported. The palaeomagnetic analysis took into account rock magnetism and directional analysis. The former reveals that most samples show stable single domain and superparamagnetic particles of Ti-poor magnetite and haematite. Natural remanent magnetisation directions were determined by progressive alternating field demagnetisation methodology. Directional analysis shows normal directions between samples 18 to 39 and 85 to 92; however, during the Early and Late Holocene in samples principally from RC40 to 84 ‘anomalous’ directions occurred. There is a significant westward shift in declination of ~80°, and a conspicuous fluctuating inclination in the lower part of the section during the Early Holocene at ≥9.5 kya and before ~12.0/13.0 kya. This palaeomagnetic record might become a chronostratigraphical marker for latest Pleistocene/Holocene sedimentary deposits in South Africa. Our two new accelerator mass spectrometry radiocarbon dates for the sampled deposit are 9500±50 BP and 1115±30 BP. Significance • The study provides new accelerator mass spectrometry dates on the chronological sequence existing in Rose Cottage Cave. • The findings contribute to the knowledge of the geomagnetic field behaviour since the terminal Pleistocene to the Late Holocene in a period spanning the last 13 000/12 000 years. • This palaeomagnetic record might become a chronostratigraphical marker for the latest Pleistocene/ Holocene sedimentary deposits in South Africa. |
format |
Article in Journal/Newspaper |
author |
Hugo G. Nami Carlos A. Vasquez Lyn Wadley Paloma de la Peña |
author_facet |
Hugo G. Nami Carlos A. Vasquez Lyn Wadley Paloma de la Peña |
author_sort |
Hugo G. Nami |
title |
Detailed palaeomagnetic record at Rose Cottage Cave, South Africa: Implications for the Holocene geomagnetic field behaviour and chronostratigraphy |
title_short |
Detailed palaeomagnetic record at Rose Cottage Cave, South Africa: Implications for the Holocene geomagnetic field behaviour and chronostratigraphy |
title_full |
Detailed palaeomagnetic record at Rose Cottage Cave, South Africa: Implications for the Holocene geomagnetic field behaviour and chronostratigraphy |
title_fullStr |
Detailed palaeomagnetic record at Rose Cottage Cave, South Africa: Implications for the Holocene geomagnetic field behaviour and chronostratigraphy |
title_full_unstemmed |
Detailed palaeomagnetic record at Rose Cottage Cave, South Africa: Implications for the Holocene geomagnetic field behaviour and chronostratigraphy |
title_sort |
detailed palaeomagnetic record at rose cottage cave, south africa: implications for the holocene geomagnetic field behaviour and chronostratigraphy |
publisher |
Academy of Science of South Africa |
publishDate |
2020 |
url |
https://doi.org/10.17159/sajs.2020/6550 https://doaj.org/article/da4f4a1a940c482e8b5e1b9581051a48 |
long_lat |
ENVELOPE(8.308,8.308,63.772,63.772) |
geographic |
Kya |
geographic_facet |
Kya |
genre |
Geomagnetic Pole |
genre_facet |
Geomagnetic Pole |
op_source |
South African Journal of Science, Vol 116, Iss 1/2 (2020) |
op_relation |
https://www.sajs.co.za/article/view/6550 https://doaj.org/toc/1996-7489 doi:10.17159/sajs.2020/6550 1996-7489 https://doaj.org/article/da4f4a1a940c482e8b5e1b9581051a48 |
op_doi |
https://doi.org/10.17159/sajs.2020/6550 |
container_title |
South African Journal of Science |
container_volume |
116 |
container_issue |
1/2 |
_version_ |
1766006077020700672 |