Micromagnetic Tomography for Paleomagnetism and Rock-Magnetism.

Autor: de Groot LV; Paleomagnetic laboratory Fort Hoofddijk Faculty of Geosciences Utrecht University Utrecht The Netherlands., Fabian K; Department of Geoscience and Petroleum Norwegian University of Science and Technology Trondheim Norway., Béguin A; Paleomagnetic laboratory Fort Hoofddijk Faculty of Geosciences Utrecht University Utrecht The Netherlands.; Department of Geoscience and Petroleum Norwegian University of Science and Technology Trondheim Norway., Kosters ME; Paleomagnetic laboratory Fort Hoofddijk Faculty of Geosciences Utrecht University Utrecht The Netherlands., Cortés-Ortuño D; Paleomagnetic laboratory Fort Hoofddijk Faculty of Geosciences Utrecht University Utrecht The Netherlands., Fu RR; Department of Earth and Planetary Sciences Harvard University Cambridge MA USA., Jansen CML; Paleomagnetic laboratory Fort Hoofddijk Faculty of Geosciences Utrecht University Utrecht The Netherlands., Harrison RJ; Department of Earth Sciences University of Cambridge Cambridge UK., van Leeuwen T; Mathematical Institute Faculty of Sciences Utrecht University Utrecht The Netherlands.; Department of Computational Imaging Centrum Wiskunde & Informatica (CWI) Amsterdam The Netherlands., Barnhoorn A; Department of Geoscience and Engineering Faculty of Civil Engineering and Geosciences Delft University of Technology Delft The Netherlands.
Jazyk: angličtina
Zdroj: Journal of geophysical research. Solid earth [J Geophys Res Solid Earth] 2021 Oct; Vol. 126 (10), pp. e2021JB022364. Date of Electronic Publication: 2021 Oct 13.
DOI: 10.1029/2021JB022364
Abstrakt: Our understanding of the past behavior of the geomagnetic field arises from magnetic signals stored in geological materials, e.g., (volcanic) rocks. Bulk rock samples, however, often contain magnetic grains that differ in chemistry, size, and shape; some of them record the Earth's magnetic field well, others are unreliable. The presence of a small amount of adverse behaved magnetic grains in a sample may already obscure important information on the past state of the geomagnetic field. Recently it was shown that it is possible to determine magnetizations of individual grains in a sample by combining X-ray computed tomography and magnetic surface scanning measurements. Here we establish this new Micromagnetic Tomography (MMT) technique and make it suitable for use with different magnetic scanning techniques, and for both synthetic and natural samples. We acquired reliable magnetic directions by selecting subsets of grains in a synthetic sample, and we obtained rock-magnetic information of individual grains in a volcanic sample. This illustrates that MMT opens up entirely new venues of paleomagnetic and rock-magnetic research. MMT's unique ability to determine the magnetization of individual grains in a nondestructive way allows for a systematic analysis of how geological materials record and retain information on the past state of the Earth's magnetic field. Moreover, by interpreting only the contributions of known magnetically well-behaved grains in a sample, MMT has the potential to unlock paleomagnetic information from even the most complex, crucial, or valuable recorders that current methods are unable to recover.
Competing Interests: The authors declare no conflicts of interest relevant to this study.
(© 2021 The Authors.)
Databáze: MEDLINE
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