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| Titel |
Multispecimen and Thellier type paleointensity determinations from postglacial lavas of Snaefell volcano, Iceland |
| VerfasserIn |
Elisabeth Tauber, Franz Josef Türk, Roman Leonhardt |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250056335
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| Zusammenfassung |
| Samples from fourteen different lava flows were taken from the Snaefells peninsula, west
Iceland. All sampled sites correspond to post-glacial Holocene lava flows related to volcanic
activity at Snaefells volcano. The samples were subjected to paleomagnetic and
rock magnetic analyses in order to obtain reliable intensities and directions of the
ancient magnetic field. Curie-temperatures, measurements of anisotropy of magnetic
susceptibility (AMS) and thermally dependent ARM measurements are used to
subdivide the samples into specific groups regarding alteration and mineralogy.
Paleodirection results yield inclinations between 54° and 82° and declinations between 290°
and 45°, as expected for the high northern latitude. According to rock magnetic
results and the classification into alteration- and mineralogytypes a pre-selection for
Thellier-measurements was conducted. Thirty-eight samples were chosen for a modified
Thellier-type paleointensity determination which includes alteration checks and
domain state checks. A minimum of seven samples in each case from five sites were
additionally subjected to a domain state sensible multispecimen protocol (MSPDSC).
Results compare very well with a higher success rate using the MSPDSC technique.
The results allow for the first time to estimate the previously unknown ages of the
Holocene flows in the vivinity of Snaefell using a Bayesian archeomagnetic dating
approach, thus providing valuable information for volcanogenic hazard analysis. |
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