Santonian

Magnetostratigraphy of Turonian – Santonian strata on the Samara Right Bank

Authors: Gujikova A. A., Grishchenko V. A., Fomin V. A., Baraboshkin E. Y., Shelepov D. A.

The paper presents the results of petro- and paleomagnetic studies of two sections of Turonian – Santonian on the Samara Right Bank – near Novodevichye, Podval’e villages and detailed geological description of the Novodevichye section. The magnetostratigraphic subdivision and detailed correlation of the sections were carried out. Unknown unconformity in the Podval’e section was recognized.

The Reversal Polarity Zone in Turonian-Coniacian of the Northern End of DonoMedvediza Dislocations

Authors: Gujikova A. A., Pervushov E. M., Ryabov I. P., Fomin V. A.

The Gubkino Horizon (Turonian-Coniacian) in the Bolshoy Kamenny ovrag section (Zhirnovsk town, Volgograd Region) has not been purposefully studied so far. As a result of biostratigraphic and magnetostratigraphic researches the carbonate rocks of the Gubkino Horizon were first divided into zones based on benthic foraminifera complexes and characterized by geomagnetic polarity and rock-magnetism data. The most part of the Bolshoy Kamenny ovrag section is covered by the reverse polarity zone.

The Santonian Stage in Volsk-Khvalynsk Structural Zone. Paper 2. Biostratigraphy and the Modern Structural Position

Authors: Pervushov E. M., Seltzer V. B., Kalyakin E. A., Ryabov I. P.

The fossil assemblage taxonomical composition analysis of upper Coniacianlower Santonian, upper Santonian and lower Campanian deposits is demonstrated. The upper Coniacian and lower Santonian deposits planoconformity has been recorded, the thin upper Santonian deposits presence has been proved and the lower Campanian subface position has been defined. Fractional biostratigraphy subdivision of the Coniacian – lower Campanian interval was carried out. The distinguished strata were traced within Volsk-Khvalynsky district.

The Santonian Stage in Volsk-Khvalynsk Structural Zone. Paper 1. The Research History and the Composition of Sections

Authors: Pervushov E. M., Seltzer V. B., Kalyakin E. A., Ryabov I. P.

The horizon enriched in glauconite and phosphorite was revealed at the carbonatic outcrops near Volsk in the Coniacian and Campanian stage deposits. The short descriptions of studying sections are presented. The spread of synchronous deposits within Khvalynsky district was traced. The Lower and Upper Santonian and the Campanian age deposits are proved by the presence of the inoceramids, belemnites and echinoides. Its vertical distribution was traced.

Contubernium Ochevi (Porifera, Hexactinellida)

Authors: Pervushov E. M.

Among the Late Cretaceous Ventriculitidae, with the most simply constructed pariform skeleton, representatives characterized by unusual neoplasms were identified. On the paragastric surface after the lapel of these sponges (Contubernium), cone-shaped submodules are regularly based, the appearance of which is associated with incomplete blastogenesis. Paragastra of submodules are not associated with the atrium, therefore, Contubernium is considered as a perifrontal organism, occupying an intermediate position between single and modular forms of spongia.

Integrated Bio and Magnetostratigraphic Study of the ≪Ozerki≫ Sections (Upper Cretaceous, Right Bank of the Volga in the Saratov Region). Paper 2. Oryctocoenosis Characteristics and Biostratigraphy

Authors: Pervushov E. M., Seltzer V. B., Kalyakin E. A., Fomin V. A., Ryabov I. P., Ilinskiy E. I., Gujikova A. A., Biryukov A. В., Surinskiy A. M.

In the ≪Ozerki≫ sections, in the terrigenous and carbonate rocks, a faunal complex has been determined – unusually diversified and relatively abundant for the right-bank part of the Saratov Region. Examination of the specified groups of fossil invertebrates has allowed to propose variants for biostratigraphic division and correlation of the sections under consideration. The carbonate rocks are supposed to belong to the Turonian-Coniacian and the underlying terrigenouscarbonate rocks are regarded as the Lower Turonian ones.

Integrated bio and Magnetostratigraphic Study of the ≪Ozerki Sections≫ (Upper Cretaceous, Right Bank of the Volga in the Saratov Region). Paper 1. Section Characteristics, Results of Petromagnetic and Magnetic-mineralogical Examinations

Authors: Pervushov E. M., Seltzer V. B., Kalyakin E. A., Fomin V. A., Ryabov I. P., Ilinskiy E. I., Gujikova A. A., Biryukov A. В., Surinskiy A. M.

In the right-bank part of the Saratov Region, a section of terrigenous and carbonate rocks has been determined to underlie the ≪sponge≫ horizon conventionally dated back to the Santonian. The maximum thickness of the marls, constituting a substantial portion of the section, occurs in the western part of the region. Field description is presented alongside with the correlation scheme of the recognized stratified intervals in the three joined Ozerki objects and the results of petromagnetic and magnetic-mineralogical examinations in the carbonate rock interval.

The Santonian – Campanian Rock Boundary Interval within the Zhirnovsk Uplift (Volgograd Region)

Authors: Pervushov E. M., Seltzer V. B., Kalyakin E. A., Gujikova A. A.

A lithologically continuous Santonian and Campanian rock section has been examined; the character of rock interrelations has been determined as the one common to the junction area of the northern part of the Don-Medveditsa and the southern termination of the Rtishchevo‑Balanda swells and the Karamysh depression.