The Blake geomagnetic excursion recorded in a radiometrically dated speleothem
One of the most important developments in geomagnetism has been the recognition of polarity excursions of the Earth's magnetic field. Accurate timing of the excursions is a key point for understanding the geodynamo process and for magnetostratigraphic correlation. One of the best-known excursio...
| Main Authors: | , , , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
| Published: |
2013
|
| Online Access: | https://hdl.handle.net/10356/98166 http://hdl.handle.net/10220/10861 |
| _version_ | 1826123507371606016 |
|---|---|
| author | Osete, María-Luisa Martín-Chivelet, Javier Rossi, Carlos Edwards, R. Lawrence Egli, Ramon Muñoz-García, M. Belén Wang, Xianfeng Pavón-Carrasco, F. Javier Heller, Friedrich |
| author2 | Earth Observatory of Singapore |
| author_facet | Earth Observatory of Singapore Osete, María-Luisa Martín-Chivelet, Javier Rossi, Carlos Edwards, R. Lawrence Egli, Ramon Muñoz-García, M. Belén Wang, Xianfeng Pavón-Carrasco, F. Javier Heller, Friedrich |
| author_sort | Osete, María-Luisa |
| collection | NTU |
| description | One of the most important developments in geomagnetism has been the recognition of polarity excursions of the Earth's magnetic field. Accurate timing of the excursions is a key point for understanding the geodynamo process and for magnetostratigraphic correlation. One of the best-known excursions is the Blake geomagnetic episode, which occurred during marine isotope stage MIS 5, but its morphology and age remain controversial. Here we show, for the first time, the Blake excursion recorded in a stalagmite which was dated using the uranium-series disequilibrium techniques. The characteristic remanent magnetisation is carried by fine-grained magnetite. The event is documented by two reversed intervals (B1 and B2). The age of the event is estimated to be between 116.5±0.7 kyr BP and 112.0±1.9 kyr BP, slightly younger (∼3–4 kyr) than recent estimations from sedimentary records dated by astronomical tuning. Low values of relative palaeointensity during the Blake episode are estimated, but a relative maximum in the palaeofield intensity coeval with the complete reversal during the B2 interval was observed. Duration of the Blake geomagnetic excursion is 4.5 kyr, two times lower than single excursions and slightly higher than the estimated diffusion time for the inner core (∼3 kyr). |
| first_indexed | 2024-10-01T06:05:48Z |
| format | Journal Article |
| id | ntu-10356/98166 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T06:05:48Z |
| publishDate | 2013 |
| record_format | dspace |
| spelling | ntu-10356/981662020-03-07T12:45:26Z The Blake geomagnetic excursion recorded in a radiometrically dated speleothem Osete, María-Luisa Martín-Chivelet, Javier Rossi, Carlos Edwards, R. Lawrence Egli, Ramon Muñoz-García, M. Belén Wang, Xianfeng Pavón-Carrasco, F. Javier Heller, Friedrich Earth Observatory of Singapore One of the most important developments in geomagnetism has been the recognition of polarity excursions of the Earth's magnetic field. Accurate timing of the excursions is a key point for understanding the geodynamo process and for magnetostratigraphic correlation. One of the best-known excursions is the Blake geomagnetic episode, which occurred during marine isotope stage MIS 5, but its morphology and age remain controversial. Here we show, for the first time, the Blake excursion recorded in a stalagmite which was dated using the uranium-series disequilibrium techniques. The characteristic remanent magnetisation is carried by fine-grained magnetite. The event is documented by two reversed intervals (B1 and B2). The age of the event is estimated to be between 116.5±0.7 kyr BP and 112.0±1.9 kyr BP, slightly younger (∼3–4 kyr) than recent estimations from sedimentary records dated by astronomical tuning. Low values of relative palaeointensity during the Blake episode are estimated, but a relative maximum in the palaeofield intensity coeval with the complete reversal during the B2 interval was observed. Duration of the Blake geomagnetic excursion is 4.5 kyr, two times lower than single excursions and slightly higher than the estimated diffusion time for the inner core (∼3 kyr). 2013-07-01T06:42:27Z 2019-12-06T19:51:41Z 2013-07-01T06:42:27Z 2019-12-06T19:51:41Z 2012 2012 Journal Article Osete, M.-L., Martín-Chivelet, J., Rossi, C., Edwards, R. L., Egli, R., Muñoz-García, M. B., et al. (2012). The Blake geomagnetic excursion recorded in a radiometrically dated speleothem. Earth and Planetary Science Letters, 353-354, 173-181. 0012-821X https://hdl.handle.net/10356/98166 http://hdl.handle.net/10220/10861 10.1016/j.epsl.2012.07.041 en Earth and planetary science letters © 2012 Elsevier B.V. |
| spellingShingle | Osete, María-Luisa Martín-Chivelet, Javier Rossi, Carlos Edwards, R. Lawrence Egli, Ramon Muñoz-García, M. Belén Wang, Xianfeng Pavón-Carrasco, F. Javier Heller, Friedrich The Blake geomagnetic excursion recorded in a radiometrically dated speleothem |
| title | The Blake geomagnetic excursion recorded in a radiometrically dated speleothem |
| title_full | The Blake geomagnetic excursion recorded in a radiometrically dated speleothem |
| title_fullStr | The Blake geomagnetic excursion recorded in a radiometrically dated speleothem |
| title_full_unstemmed | The Blake geomagnetic excursion recorded in a radiometrically dated speleothem |
| title_short | The Blake geomagnetic excursion recorded in a radiometrically dated speleothem |
| title_sort | blake geomagnetic excursion recorded in a radiometrically dated speleothem |
| url | https://hdl.handle.net/10356/98166 http://hdl.handle.net/10220/10861 |
| work_keys_str_mv | AT osetemarialuisa theblakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT martinchiveletjavier theblakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT rossicarlos theblakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT edwardsrlawrence theblakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT egliramon theblakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT munozgarciambelen theblakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT wangxianfeng theblakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT pavoncarrascofjavier theblakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT hellerfriedrich theblakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT osetemarialuisa blakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT martinchiveletjavier blakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT rossicarlos blakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT edwardsrlawrence blakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT egliramon blakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT munozgarciambelen blakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT wangxianfeng blakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT pavoncarrascofjavier blakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem AT hellerfriedrich blakegeomagneticexcursionrecordedinaradiometricallydatedspeleothem |