Paleomagnetic and rock magnetic study of Lower Devonian red beds from Podolia: remagnetization problems

Abstract

Results of paleomagnetic studies of red bed Early Devonian deposits of Podolia, which make the Dniester series (southwestern Ukraine, the Dniester basin) have been given. As a result two components of natural remanent magnetization have been subdivided in addition to viscous one. The first one has got south-southwestern declination and negative inclination, it is identified in almost all samples within the limits of deblocking temperatures from 150—200°С to 530—630°С. Its corresponding paleomagnetic pole (47°S, 351,5°E) is close to the Permian fragment of APWP for the Baltic/Stabile Europe. Its bearers are newly-formed magnetic minerals (secondary authigenous hematite), responsible for production of “late” chemical magnetization. The second component is subdivided in some samples within the limits from 590—610°С to 680—690°С, it has got southwestern declination and positive inclination. Its corresponding paleomagnetic pole (2.3°S, 338.4°E) is drawn towards Early Devonian fragment of APWP This component is caused by presence of detritic grains of hematite. There are solid grounds for consideration of this magnetization to be primary one, which reflects the direction of the Devonian field. New results are in good agreement with paleomagnetic directions obtained earlier in this area for red beds and grey beds of Early Devonian