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RESET: A Method to Monitor Thermoremanent Alteration in Thellier‐Series Paleointensity Experiments
Author(s) -
Wang Huapei,
Kent Dennis V.
Publication year - 2021
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2020gl091617
Subject(s) - thermoremanent magnetization , lava , geology , earth's magnetic field , dynamo , paleomagnetism , archaeomagnetic dating , series (stratigraphy) , rock magnetism , reset (finance) , geophysics , secular variation , seismology , paleontology , mineralogy , magnetic field , remanence , magnetization , volcano , physics , quantum mechanics , economics , financial economics
Accurately estimating the paleomagnetic field intensity recorded in terrestrial and planetary materials is the key to understanding dynamo processes. Thellier‐series stepwise‐heating methods with partial thermoremanent magnetization (pTRM) checks for alteration are considered the most reliable technique even though pTRM checks are shown to be incapable of detecting the entirety of thermal alteration. We utilize a recently developed multidomain‐correction experiment (or RESET) to monitor thermally induced magnetic property alteration that may happen to the very specimen used in Thellier‐series experiments. We also use rock magnetic property changes to track the physicochemical alteration of fresh companion specimens of Galapagos lavas that were previously used for paleointensity determinations. Our results show that laboratory heating induced thermal alteration of a typical Galapagos lava sample starts to occur at around 500°C. It escaped detection by pTRM checks but was caught by our RESET method.