ИСТИНА

With the aim to study the magnetostratigraphy of deposits belong to the Upper Sarmatian - Lower Maeotian, the geological samples of a Panagia section (Taman Peninsula, Russia) were collected. The section is composed mainly of clays. The total thickness of collected deposits is ~ 30 m, the number of the samples is 21. Examination of a composition of a ferromagnetic fraction was carried out using the dependences of the magnetic susceptibility on temperature. This thermomagnetic analysis showed that the iron sulfide, for example, pyrrhotite or greigite, is the main carrier of the natural remanent magnetization NRM. Coercivity of remanence Bcr values, determined from backfield demagnetization measurements, range between ~20 and 63 mT. In order to determine true NRM directions, we studied the anisotropy of magnetic susceptibility. The rock samples possess the planar anisotropy, which is characteristic of normal sedimentary rocks. Alternating field AF-demagnetization of the collection (three duplicates from each level) were used for obtaining NRM vector angle elements. Demagnetization results were analyzed using orthogonal plots and stereographic projections. Polarity components were isolated in most samples between 15-25 mT. The values of the declination D and inclination I of the NRM satisfactory agree for three duplicates from each level. It makes possible to average angle elements and construct curves of I and D variations on the thickness of the section. The collection of samples of Popov Kamen section (Taman peninsula, Russia) which belongs too to the Upper Sarmatian - Lower Maeotion was studied by rock magnetic and paleomagnetic methods in our previous work [Pilipenko, Trubikhin, 2011; Trubikhin, Pilipenko, 2014]. As a result of previous research the studied interval of Upper Sarmatian deposits can be interpreted as Chron C5n, and the interval of Lower Maeotian deposits correspond to the C3Br, C3Bn, C3Ar Chrons. New magnetostratigraphic data on the Upper Sarmatian-Lower Maeotian transition are important for dating the biotic event related to marine transgression at the beginning of the early Maeotian.