A. D. Mutovkin

Comprehensive studies of the Caspian Sea system during cruise 35 of the R/V Rift

141 A interdisciplinary expedition was conducted aboard the R/V Rift (cruise 35; June 4–19, 2010) to study the system of the Caspian Sea. The hydrophysi cal, hydrochemical, sedimentological, and geological characteristics of the atmosphere, the water’s thick ness, and the bottom sediments were investigated. The works were performed in the Middle Caspian Sea and lengthwise the submeridional transect up to the South Basin of the Caspian Sea (Fig. 1).

New result of the seismic facies analysis of the Quaternary deposits in the western Atlantic

1256 The regular Transatlantic geological–geophysical expeditions on R/Vs Akademik Ioffe and Akademik Sergei Vavilov (Shirshov Institute of Oceanology, Rus sian Academy of Sciences) starting from 2009 have made the foundation for studying the inner structure and occurrence conditions of the main genetic types of deep water Quaternary bottom sediments of the Atlantic Ocean along the submeridional geotraverses [1–4]. The SES 2000 deep parametric narrow angle profiler used in these expeditions allows obtaining high resolution (tens of centimeters) seismoacoustic sections of bottom sediments with a depth extent of up to 100 m beneath the bottom at sea depths of up to 6000 m. For lithological–stratigraphic interpretation of the distinguished reference acoustic images (seis mofacies) at the key points of the seismoacoustic pro file, sediment cores are collected. A direct correlation between the sections from boreholes of deep sea drill ing, crossing the seismic profile, enables us to reveal sedimentation mechanisms leading to formation of seismofacies [1, 2, 4].

Slump structures in quaternary slope sediments of the northern Derbent Basin (Caspian Sea)

During Cruise 20–3 of the R/V Rift (April, 2006), the area that includes the shelf and slope of the Derbent Basin in the northern Middle Caspian was studied using the continuous seismoacoustic profiling method. In accordance with the previous standpoint, two Pleistocene deltaic complexes formed in the Enotaevian and Mangyshlakian time are defined in this area. The seismoacoustic records obtained for the northern slope of the Derbent Basin demonstrate the development of specific rootless exogenic-gravitational fold structures in the upper (∼150–200 m) Quaternary part of the sedimentary sequence. The Quaternary section encloses angular unconformities indicating the pulsating mode of gravitational processes in the northern slope of the basin. South-dipping gravitational normal faults (and/or normal fault-related flexures) displacing the bottom surface and uppermost sedimentary layers (with vertical amplitudes up to 5–6 m) were defined in the southern part of the study area. Several impulses of the submarine slump structures predated and accompanied the deposition of the upper deltaic sequence (Mangyshlakian), although their most intense formation took place later during the Novocaspian (Holocene) time. Thus, the structural analysis of the seismoacoustic data revealed intense development of different-origin and different-age gravitational structures within the Quaternary sediments in the northern slope of the Derbent Basin. These results should be taken into consideration when designing, building, and operating submarine constructions in order to prevent potential natural hazards and reduce their consequences.

Seismic acoustic research in the area of Golubaya Bay of the Black Sea conducted by the R/V Ashamba

One of the main goals of the expedition was the acceptance trial and development of operational techniques for the SES 2000 Light Plus parametric subbottom profiler newly acquired within the frame of the State Contract (produced by Innomar Technolo gie GmbH, Germany) consisting of a new generation acoustic bottom profiler and a sidescan sonar pro duced by the same company and structurally compat ible and combined with the profiler. In addition, the obtained data were compared with the results of the hardware–software complex Teont Shelf, which is a complete system for research by single channel con tinuous seismic profiling (CSP) using a sparker type emitter and a pick up loop 20 m long. The simulta neous operation of the above mentioned systems in close proximity to each other made it possible to clar ify the degree of their mutual influence and enhance the interpretation of the data.