Multi-proxy identification of the Laschamp geomagnetic field excursion in Lake Pupuke, New Zealand
(2011) In Earth and Planetary Science Letters 311(1-2). p.155-164- Abstract
- We present palaeomagnetic and cosmogenic radionuclide records of the Laschamp geomagnetic excursion in Lake Pupuke, a maar lake in Auckland, New Zealand. Laschamp was identified by a combination of relative palaeointensity, (10)Be and (14)C data from the lake sediments and represents the first such record from the Southern Hemisphere. Despite the high organic carbon content, which causes relatively weak natural remanent magnetisations, the geomagnetic intensity minimum associated with the Laschamp excursion is identifiable as a relative palaeointensity minimum that is synchronous with (i) a peak in (10)Be concentration and (ii) an anomaly in Delta(14)C. The Lake Pupuke time scale, provided by (14)C data calibrated with INTCAL09, places the... (More)
- We present palaeomagnetic and cosmogenic radionuclide records of the Laschamp geomagnetic excursion in Lake Pupuke, a maar lake in Auckland, New Zealand. Laschamp was identified by a combination of relative palaeointensity, (10)Be and (14)C data from the lake sediments and represents the first such record from the Southern Hemisphere. Despite the high organic carbon content, which causes relatively weak natural remanent magnetisations, the geomagnetic intensity minimum associated with the Laschamp excursion is identifiable as a relative palaeointensity minimum that is synchronous with (i) a peak in (10)Be concentration and (ii) an anomaly in Delta(14)C. The Lake Pupuke time scale, provided by (14)C data calibrated with INTCAL09, places the (10)Be maximum at the same time as a (10)Be maximum in Greenland ice cores when secured to the GICC05 time scale. The central age of the Laschamp geomagnetic excursion in Lake Pupuke as defined by the (10)Be prediction peak is c. 41 kyr, which confirms its global application as a palaeomagnetic isochron. Anomalous palaeomagnetic directional data at c. 32 kyr in the Lake Pupuke sediments may represent the Mono Lake geomagnetic excursion, but tephra layers caused by frequent eruptions in the Auckland volcanic field during this excursion probably disrupted the palaeointensity signal. The study highlights the value of combining traditional palaeomagnetic methods with measurements of cosmogenic radionuclides in the quest for accurate and precise geochronologies during MIS3, a time of rapid global climate change. (C) 2011 Elsevier B.V. All rights reserved. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/2333509
- author
- Nilsson, Andreas LU ; Muscheler, Raimund LU ; Snowball, Ian LU ; Aldahan, Ala ; Possnert, Goran ; Augustinus, Paul ; Atkin, Daniel and Stephens, Tom
- organization
- publishing date
- 2011
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Laschamp excursion, geomagnetic field intensity, cosmogenic, radionuclides, palaeomagnetism, lake sediments, Lake Pupuke
- in
- Earth and Planetary Science Letters
- volume
- 311
- issue
- 1-2
- pages
- 155 - 164
- publisher
- Elsevier
- external identifiers
-
- wos:000298270100014
- scopus:81155139655
- ISSN
- 1385-013X
- DOI
- 10.1016/j.epsl.2011.08.050
- language
- English
- LU publication?
- yes
- id
- c59928b7-e550-4784-acfd-f0d93343f78b (old id 2333509)
- date added to LUP
- 2016-04-01 10:40:48
- date last changed
- 2022-02-25 03:56:51
@article{c59928b7-e550-4784-acfd-f0d93343f78b, abstract = {{We present palaeomagnetic and cosmogenic radionuclide records of the Laschamp geomagnetic excursion in Lake Pupuke, a maar lake in Auckland, New Zealand. Laschamp was identified by a combination of relative palaeointensity, (10)Be and (14)C data from the lake sediments and represents the first such record from the Southern Hemisphere. Despite the high organic carbon content, which causes relatively weak natural remanent magnetisations, the geomagnetic intensity minimum associated with the Laschamp excursion is identifiable as a relative palaeointensity minimum that is synchronous with (i) a peak in (10)Be concentration and (ii) an anomaly in Delta(14)C. The Lake Pupuke time scale, provided by (14)C data calibrated with INTCAL09, places the (10)Be maximum at the same time as a (10)Be maximum in Greenland ice cores when secured to the GICC05 time scale. The central age of the Laschamp geomagnetic excursion in Lake Pupuke as defined by the (10)Be prediction peak is c. 41 kyr, which confirms its global application as a palaeomagnetic isochron. Anomalous palaeomagnetic directional data at c. 32 kyr in the Lake Pupuke sediments may represent the Mono Lake geomagnetic excursion, but tephra layers caused by frequent eruptions in the Auckland volcanic field during this excursion probably disrupted the palaeointensity signal. The study highlights the value of combining traditional palaeomagnetic methods with measurements of cosmogenic radionuclides in the quest for accurate and precise geochronologies during MIS3, a time of rapid global climate change. (C) 2011 Elsevier B.V. All rights reserved.}}, author = {{Nilsson, Andreas and Muscheler, Raimund and Snowball, Ian and Aldahan, Ala and Possnert, Goran and Augustinus, Paul and Atkin, Daniel and Stephens, Tom}}, issn = {{1385-013X}}, keywords = {{Laschamp excursion; geomagnetic field intensity; cosmogenic; radionuclides; palaeomagnetism; lake sediments; Lake Pupuke}}, language = {{eng}}, number = {{1-2}}, pages = {{155--164}}, publisher = {{Elsevier}}, series = {{Earth and Planetary Science Letters}}, title = {{Multi-proxy identification of the Laschamp geomagnetic field excursion in Lake Pupuke, New Zealand}}, url = {{http://dx.doi.org/10.1016/j.epsl.2011.08.050}}, doi = {{10.1016/j.epsl.2011.08.050}}, volume = {{311}}, year = {{2011}}, }