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New experimental equipment for the study of chemical remagnetization of rocks during water-rock interactionстатья
Статья опубликована в высокорейтинговом журнале
Статья опубликована в журнале из списка Web of Science и/или Scopus- Авторы: Lubnina N.V., Bychkov A.Yu, Tarasov N.A.
- Журнал: Tectonophysics
- Год издания: 2021
- Издательство: Elsevier BV
- Местоположение издательства: Netherlands
- Аннотация: Рalaeomagnetic studies of the Karelian Craton Precambrian complexes the north–north-east down magnetic component (named component 'B') was detected. This magnetic component was formed as a result of chemical re-magnetization under the hydrothermal alteration. The possible age for the rocks to acquire this component of magnetization is indirectly estimated at 1.76–1.79 Ga based on isotope data. To explain the possibility of the formation of magnetic minerals under the hydrothermal impact, experimental studies were conducted. The experiments were carried out in autoclaves made of titanium alloy with oriented rock samples in a special furnace shielded from an external magnetic field with a controlled internal magnetic field. The experiments with duration of 15-30 days were carried out at 300-450 °C and up to 1000 bar using different composition of solutions. Before the experiment, of basalts, gabbros and norites samples from various formations of the Karelian Craton were studied by paleomagnetic methods and were demagnetized. The results showed that single domain magnetite was formed during the hydrothermal transformation. In this case, the magnetization direction corresponds to the internal magnetic field. The most intensity of the magnetite formation was observed in NaCl brines. Thermodynamic calculations were performed using the program HCh [1]. The results confirmed the stability of magnetite during hydrothermal exposure to basalts, gabbros and norites. The source of brines may be the Jatulian evaporates formation (2.1 Ga). Leaching brines occurred on the hydrothermal impact during late thermal events. Thermal events associated with large igneous provinces (LIP) retained the recording of the magnetic direction of the hydrothermal process time. Restoring of component 'B' allows exploring the history of LIP of the Karelian Craton.
- Добавил в систему: Лубнина Наталия Валерьевна