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Characteristics of Orthogonal and Arai–Nagata Diagrams on Titanomagnetite-Bearing Basalts with Laboratory-Induced Mutually Perpendicular Thermal and Chemical Remanent Magnetizationsстатья
- Авторы: Gribov S.K., Shcherbakov V.P., Tsel’movich V.A., Aphinogenova N.A.
- Журнал: Izvestiya. Physics of the Solid Earth
- Том: 61
- Номер: 5
- Год издания: 2025
- Издательство: Pleiades Publishing, Inc.
- Местоположение издательства: New York, USA
- Первая страница: 854
- Последняя страница: 866
- Оригинальные версии: Свойства ортогональных диаграмм и диаграмм Араи-Нагаты на титаномагнетитсодержащих базальтах с лабораторно индуцированными взаимно перпендикулярными термоостаточной и химической остаточной намагниченностями
- DOI: 10.1134/S1069351325700636
- Аннотация: Abstract—The paper evaluates the influence of secondary magnetization on the determination of characteristic component and paleointensity in basalt rocks whose magnetic remanence is carried by titanomagnetitewith varying degrees of oxidation. To this end, laboratory experiments on magnetization acquisition were performed on basalt samples from the submerged Reykjanes Ridge, North Atlantic. The “primary” total thermoremanent magnetization TRM was imparted to rock samples by their soaking at temperature of 600°C followed by cooling in a magnetic field of 50 μT. The “secondary” chemical remanent magnetization CRM,perpendicular to TRM, was overprinted by subsequent soaking of samples at 350 °C for 200 h in the samefield. Directly at a temperature of 350°C, temporal monitoring of the changes in the TRM and CRM components was carried out. The samples with laboratory-induced total remanent magnetizations were subjectedto the Thellier-type paleointensity experiments, and the results were used to construct the Arai–Nagata andZijderveld diagrams. It is shown that CRM is formed on the new ferrimagnetic phases that resulted from theoxidation of an unstable fraction of titanomagnetite, and the CRM intensity critically depends on the degreeof oxidation of the initial material. All the constructed diagrams have linear segments with different slopes,which are identified in the low-temperature (LT) range from 20–350 to 450°C, medium-temperature (MT)range from 450–475 to 500–530°C, and high-temperature (HT) range from 500–530 to 560–600°C. It isshown that the presence of a secondary component leads to errors in both paleodirection and paleointensitydeterminations from the primary component, and the errors are greater the greater the secondary CRM relative to the primary TRM. A new criterion of reliability of paleomagnetic data is proposed. This criterionapplies to both paleointensity and paleodirection and states that the primary component should be severaltimes as large as the secondary component.
- Добавил в систему: Цельмович Владимир Анатольевич