High paleointensities for the Canary Islands constrain the Levant geomagnetic high

作者：de Groot Lennart V; Beguin Annemarieke; Kosters Martha E; van Rijsingen Elenora M; Struijk Erzsebet L M; Biggin Andrew J; Hurst Elliot A; Langereis Cor G; Dekkers Mark J

来源：Earth and Planetary Science Letters, 2015, 419: 154-167.

DOI：10.1016/j.epsl.2015.03.020

• paleointensity
• Canary Islands
• multi-method paleointensity approach
• Thellier
• intensity highs

Understanding the behavior of enigmatic geomagnetic traits such as the Levant intensity high is currently challenged by a lack of full vector records of regional variations in the geomagnetic field. Here we apply the recently proposed multi-method paleointensity approach to a suite of 19 lavas from the Canary Islands dating between similar to 4000 BC and 1909 AD. Our new record reveals high paleointensities (VADMs >120 ZAm(2)) coinciding with and shortly after the peak in geomagnetic intensity in the Levant at similar to 1000 BC. Furthermore our data suggests a westward movement of this geomagnetic phenomenon at a rate of 6.7-12 degrees per century. In addition to IZZI-Thellier, microwave-Thellier and the multi-specimen method, the calibrated pseudo-Thellier method is an important part of the multi-method paleointensity approach. The calibration of this relative paleointensity method was derived from a suite of Hawaiian lavas; it is improved with the results of the Canarian cooling units. Pseudo-Thellier results from samples with very low Curie temperature (<150 degrees C), however, cannot be reliably converted to absolute paleointensity estimates. The multi-method paleointensity approach yielded a reliable estimate for similar to 60% of the flows sampled - an unusually high success rate for a paleointensity study involving lavas.

• 出版日期2015-6-1