Potential Bias in Volcanic Paleomagnetic Records Due To Superimposed Chemical Remanent Magnetization
Abstract Volcanic rocks, preserving paleorecords of Earth's magnetic field, are essential to constrain the working of the geodynamo, provided their primary signal was not biased. Using a thermomagnetometer, we simulate a situation where a sample's primary record, carried by a thermoremanen...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2024-06-01
|
| Series: | Geophysical Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2024GL109630 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849725946899202048 |
|---|---|
| author | V. P. Shcherbakov F. Lhuillier S. K. Gribov V. A. Tselmovich N. A. Aphinogenova |
| author_facet | V. P. Shcherbakov F. Lhuillier S. K. Gribov V. A. Tselmovich N. A. Aphinogenova |
| author_sort | V. P. Shcherbakov |
| collection | DOAJ |
| description | Abstract Volcanic rocks, preserving paleorecords of Earth's magnetic field, are essential to constrain the working of the geodynamo, provided their primary signal was not biased. Using a thermomagnetometer, we simulate a situation where a sample's primary record, carried by a thermoremanence (TRM, acquired by cooling in air from 600°C to room temperature), is partly overprinted by a chemical remanence (CRM, acquired by 200 hr of isothermal exposure at 400°C). This situation leads to two directional and intensity components (in the form of linear segments) in the Zijderveld and Arai‐Nagata diagrams. In the case of unstable titanomagnetite grains prior to CRM acquisition, we show that both components can be strongly biased by up to ∼50° for paleodirections and ∼50% for paleointensities. In such a worst‐case scenario, the secondary CRM strongly overprints the primary TRM, rendering the common interpretation of Zijderveld and Arai‐Nagata diagrams in terms of characteristic components invalid. |
| format | Article |
| id | doaj-art-01b8403bdf6b40a9bbb01c70b8b0438e |
| institution | DOAJ |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2024-06-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-01b8403bdf6b40a9bbb01c70b8b0438e2025-08-20T03:10:21ZengWileyGeophysical Research Letters0094-82761944-80072024-06-015112n/an/a10.1029/2024GL109630Potential Bias in Volcanic Paleomagnetic Records Due To Superimposed Chemical Remanent MagnetizationV. P. Shcherbakov0F. Lhuillier1S. K. Gribov2V. A. Tselmovich3N. A. Aphinogenova4Geophysical Observatory Borok Yaroslavskaya Oblast RussiaDepartment of Earth and Environmental Sciences Ludwig‐Maximilians‐Universität Munich GermanyGeophysical Observatory Borok Yaroslavskaya Oblast RussiaGeophysical Observatory Borok Yaroslavskaya Oblast RussiaGeophysical Observatory Borok Yaroslavskaya Oblast RussiaAbstract Volcanic rocks, preserving paleorecords of Earth's magnetic field, are essential to constrain the working of the geodynamo, provided their primary signal was not biased. Using a thermomagnetometer, we simulate a situation where a sample's primary record, carried by a thermoremanence (TRM, acquired by cooling in air from 600°C to room temperature), is partly overprinted by a chemical remanence (CRM, acquired by 200 hr of isothermal exposure at 400°C). This situation leads to two directional and intensity components (in the form of linear segments) in the Zijderveld and Arai‐Nagata diagrams. In the case of unstable titanomagnetite grains prior to CRM acquisition, we show that both components can be strongly biased by up to ∼50° for paleodirections and ∼50% for paleointensities. In such a worst‐case scenario, the secondary CRM strongly overprints the primary TRM, rendering the common interpretation of Zijderveld and Arai‐Nagata diagrams in terms of characteristic components invalid.https://doi.org/10.1029/2024GL109630chemical remanent magnetizationtitanomagnetitezijderveld diagramarai diagramcharacteristic component |
| spellingShingle | V. P. Shcherbakov F. Lhuillier S. K. Gribov V. A. Tselmovich N. A. Aphinogenova Potential Bias in Volcanic Paleomagnetic Records Due To Superimposed Chemical Remanent Magnetization Geophysical Research Letters chemical remanent magnetization titanomagnetite zijderveld diagram arai diagram characteristic component |
| title | Potential Bias in Volcanic Paleomagnetic Records Due To Superimposed Chemical Remanent Magnetization |
| title_full | Potential Bias in Volcanic Paleomagnetic Records Due To Superimposed Chemical Remanent Magnetization |
| title_fullStr | Potential Bias in Volcanic Paleomagnetic Records Due To Superimposed Chemical Remanent Magnetization |
| title_full_unstemmed | Potential Bias in Volcanic Paleomagnetic Records Due To Superimposed Chemical Remanent Magnetization |
| title_short | Potential Bias in Volcanic Paleomagnetic Records Due To Superimposed Chemical Remanent Magnetization |
| title_sort | potential bias in volcanic paleomagnetic records due to superimposed chemical remanent magnetization |
| topic | chemical remanent magnetization titanomagnetite zijderveld diagram arai diagram characteristic component |
| url | https://doi.org/10.1029/2024GL109630 |
| work_keys_str_mv | AT vpshcherbakov potentialbiasinvolcanicpaleomagneticrecordsduetosuperimposedchemicalremanentmagnetization AT flhuillier potentialbiasinvolcanicpaleomagneticrecordsduetosuperimposedchemicalremanentmagnetization AT skgribov potentialbiasinvolcanicpaleomagneticrecordsduetosuperimposedchemicalremanentmagnetization AT vatselmovich potentialbiasinvolcanicpaleomagneticrecordsduetosuperimposedchemicalremanentmagnetization AT naaphinogenova potentialbiasinvolcanicpaleomagneticrecordsduetosuperimposedchemicalremanentmagnetization |