ИСТИНА |
Войти в систему Регистрация |
|
ИСТИНА ПсковГУ |
||
Paleomagnetic studies are being actively carried out, including on marine basalts: in the zones of spreading, subduction, and volcanism. The conditions for the formation and evolution of basalts under the water are extreme: increased pressure, high cooling rate, oxidative processes. Taking these factors into account for the formation and evolution of the rocks will make it possible to increase the reliability of paleomagnetic determinations from marine basalts. On pillow lavas of marine basalts sampled from the bottom of the Red Sea, magnetic properties were studied at various distances from the surface of rim. The first 7 cm of the rock were investigated, natural magnetic characteristics were obtained for each centimeter layer, thermomagnetic analysis was carried out, as well as spectral phase analysis. It has been established that, with distance from the rim, an increase in susceptibility is observed from 10⋅10-4 to 60⋅10-4 SI, and the size of titanomagnetite crystals - from 0.3 to 10 μm. The Koenigsberger parameter drops from 250 to ~ 50, and the Curie temperature - from 320 to 220 °C. NRM grows first 3 cm from the rim, then decreases. It was revealed that the Curie temperature decreases in argon, as the contact zone is approached, the titanium content in titanomagnetite decreases, and the degree of single-phase oxidation increases with the approach to the rim. It was determined that titanomagnetite is in a stoichiometric state at the distance of 4 cm from the rim. Anisotropy of natural magnetization is observed in the studied rocks. It was revealed that the inclination of natural magnetization changes with depth by 10°. The paleointensity for all layers is 70% higher than the current field in this region and is equal to 62 μT, the error is within 5%. This work is supported by the Russian Foundation for Basic Research (grant 20-05-00573).