Low-temperature demagnetization of volcanic rocks containing multi-domain magnetic grains: Implications for the Thellier paleointensity determination

• Main Authors: Ana-María Soler, Luis Alva-Valdivia, Avto Goguitchaichvili, Juan Morales
• Format: Article in Journal/Newspaper
• Language: English; Spanish
• Published: Universidad Nacional Autónoma de México, Instituto de Geofísica 2001
• Subjects: Rock-magnetism; low-temperature demagnetization; domain structure; Geophysics. Cosmic physics; QC801-809; Iceland
• Online Access: https://doaj.org/article/9251960b26cb4047a597112ef40be8ab

Thirteen samples of volcanic rocks from Caucasus, Iceland and Philippines were subjected to low-temperature treatment in order to remove the part of remanent magnetization carried by multi-domain grains. Ten to 40% of multi-domain partial thermoremanence were removed, which may help to increase the success of paleointensity experiments. A sample from the 1991 eruption of Pinatubo volcano shows a total self-reversal due to ilmeno-hematites and partial self-reversal between 500° and 575 °C due to titano-magnetites. Low temperature demagnetization applied to self-reversed remanence suggest that the high-temperature peak is almost suppressed by this treatment.