маастрихт

Upper Cretaceous Calcareous Sponges of the Southeast of East European Platform

The features of areal distribution and stratigraphic confinement of calcareous spicular sponge forms in the southeast of East European Platform are considered. The skeletons of calcareous sponges essentially representatives of the genus Porosphaera are found in the carbonates of Turonian, Coniacian, Campanian and Maastrichtian, as well as at the base of siliceous formations of the Paleocene. The Maastrichtian calcareous sponges are characterized by the highest species diversity and a wide lateral extension.

Cyclostratigraphic Analysis of the Rock Magnetic Data on Maastrichtian of the Bodrak River (SW Crimea)

Authors: Surinskiy A. M., Guzhikov A. Y.

Measurements of mass magnetic susceptibility of 2 232 samples, collected in Takma and Chakhmakhly sections (SW Crimea, Bodrak river) through every 20 cm of thickness were conducted. The cycles, supposedly corresponding to the periods of long and short eccentricities of Earth orbit and its axis obliquity were detected by Fourier transform and wavelet analysis of obtained data. The average sedimentation rate (11.7 cm/kyr) was calculated.

Faunal Assemblage of the Maastrichtian – Paleocene Intervals of Volsk Depression

Authors: Pervushov E. M., Seltzer V. B., Kalyakin E. A., Musatov V. A., Ermokhina L. I., Ilinskiy E. I., Lopyrev V. A., Romanov N. S., Khudyakov D. V., Voronkov I. R.

Terminal layers of carbonate rocks of Maastrichtian and lower intervals of Paleocene aleurite-pelitic formations are accessible for investigation in Krasny Oktyabr and Bolshevik quarries (Volsk Depression). In the bottom of the Paleocene accumulation of skeletons of calcareous and siliceous sponges has been confirmed, mollusk and elasmobranch assemblage has been determined. Biozonal stratification of the location section and oryctocomplex analysis have contributed to specification of the processes in succession of benthic forms at the Upper Cretaceous – Paleogene boundary.

First Magnetostratigraphic Data on the Maastrihtian of Mountain Crimea (Bakhchysarai Region)

Authors: Gujikova A. A.

The representative data about magnetic susceptibility, its anisotropy before and after heating up to 500°C and other petromagnetic characteristics were received on two sections of carbonate sediments of Maastrihtian – Chahmahly and Takma, located in Bakhchysarai region of the Republic of Crimea. In the studied sections there were established the magnetozones of normal and anomalous polarity, the comparison of determined zones with Geomagnetic Polarity Time Scale was conducted.

Petromagnetic Indicators of Layers with High Concentration of Cosmogenic Substance in Maastrichtian of Volga Region and Cis-Caspian Region

Authors: Gujikova A. A., Tselmovich V. A., Atkin V. S.

The level with anomalous high values of natural remanent magnetization and Koenigsberger ratios was identify in the Upper Maastrichtian of Vol’sk depression (Saratov Volga Region). The microprobe studies of samples from this layer registered elevated concentrations of microparticles of iron, nickel, intermetallics and magnetite spherules of cosmic genesis. Similar petromagnetic anomaly was detect in the uppermost of Maastrichtian in the South Cis-Caspian (Aktolagay Plateau, Kazakhstan).

Possible Changes of the Geomagnetic Field Intention in Titonian – Berrassian and Campanian – Maastrichtian

Authors: Kurazhkovskii A. Y., Kurazhkovskaya N. A., Bagaeva M. I., Gujikova A. A.

By the results of exploration of Titonian – Berriassian sections of Mountain Crimea and Campanian – Maastrichtian sections of west of the Middle Asia, Volga region and Crimea it became possible to reconstruct the special aspects of the geomagnetic field paleointensity changes. There were received the average scale of variations, that rise at the end of geological periods. It should be noted that at the end of Jurassic the average amplitude of geomagnetic field variations was lower than at the end of Cretaceous.

The Late Cretaceous Lithofacies of the Bottom Volga Region

Authors: Akhlestina E. F.

The distinctions of the late cretaceous lithofacies are considered. The genetic groups are marked. These groups conform to the different zones of the sea basin starting from littoral zones with an active hydrodynamics up to the abyssal zones and the areas of the depressions. The inharting of monotyped facial zones of different time levels is established. Three facial regions which are following each other in space are established

The Echinoids Cyclaster and Galerites from the Maastrichtian Deposits of Volga Region

Authors: Kalyakin E. A.

A first for the Volga region described two new species of echinoids and shows their stratigraphic position. Analyzed the relationship identified Maastrichtian sea urchins of the region coupled with synchronous complexes conjugate paleobiochores