Vadim Sivkov

Recent sedimentation processes in the coastal zone of the Curonian Spit (Kaliningrad region, Baltic Sea) [Jüngste Ablagerungsprozesse im K*uuml;stengebiet der Kurischen Nehrung (Raum Kaliningrad, Ostsee).]

The Curonian Spit is a sandy depositional landform that encloses the Curonian Lagoon, the biggest lagoon of the Baltic Sea. A new interpretation of the sediment distribution and sedimentation processes in the coastal zone of the Russian part of the Curonian Spit was obtained on land and offshore (using side-scan sonar, echo sounding and surfi cial sediment sampling) by a joint expedition of VSEGEI (Karpinsky Russian Geological Research Institute) and ABIORAS (Atlantic Branch of the Institute of Oceanology, Russian Academy of Science) in 2006 and 2007. The investigations found widespread coastal and seabed erosion at the attached part of the Curonian Spit and in the area adjacent to Lesnoy, providing evidence of highly active lithodynamic processes. The main reason for more intense erosion processes over recent decades is a sedi- ment defi cit in the coastal system between Cape Taran and Lesnoy. Further beach degradation and an increased possibility of spit breakthrough in storms are likely. Radiocarbon dating of the lagoons Holocene muds outcropping on the seabed showed eastward spit migration of 0.4 to 0.5 m per year in the area near Lesnoy over the last 5000 to 6000 years. Kurzfassung: Die Kurische Nehrung ist ein sandiger Landstreifen, der das Kurische Haff - die groste Lagune der Ostsee - umschliest. In den Jahren 2006 und 2007 wurden im Rahmen einer gemeinsamen Expedition von VSEGEI (Karpinsky Russian Geological Research Institute) und ABIORAS (Atlantic Branch of the Institute of Oceanology, Russian Academy of Science) die Sedimentverbreitung und die Ablagerungsprozesse im Kustengebiet des russischen Teils der Kurischen Neh- rung neu untersucht und interpretiert. Die Untersuchungen wurden mit einem Side-Scan-Sonar, mittels Echolotung und Entnahme von Oberfl achen-Sedimentproben auf dem Festland und auf dem Schelf durchgefuhrt. Sie ergaben eine ausge- dehnte Erosion des Kusten- und Meeresgrundes im Festlandbereich der Kurischen Nehrung und auf dem an Lesnoy angren- zenden Gebiet, was auf einen sehr intensiven lithodynamischen Prozess hindeutet. Der Hauptgrund fur diesen gesteigerten Erosionsprozess in den letzten Jahrzehnten ist der Mangel an Sediment im Kustenbereich zwischen Kap Taran und Lesnoy. Weiterer Kustenabbau und die erhohte Gefahr eines Nehrungsdurchbruchs bei Sturm sind wahrscheinlich. Die C 14 -Datie- rung des auf dem Meeresboden zutage tretenden Lagunen-Alluviums ergab in der Nahe von Lesnoy eine Verlagerung der

Amber Deposits in the Kaliningrad Region

Amber is one of the most valuable mineral resources of the Kaliningrad Region. It is mined by several methods, both open and closed, on sea and on land; the vast majority of this type of amber world reserves is located on the Sambian Peninsula and its continental slope. Nevertheless, geological research of amber deposits still did not carry out up to sufficient rate.

Iceberg and ice-keel ploughmarks on the Gdansk-Gotland Sill (south-eastern Baltic Sea)

New interpretation of the undulating moraine relief of the Gdansk-Gotland Sill, Baltic Sea is proposed. Relict iceberg and ice-keel ploughmarks were observed based on the integration of recently acquired side-scan sonar, multi-beam, single-beam and lithological data. The most likely time of their formation is the period of fast Scandinavian sheet retreat occurring from approximately 13.2 to 11.7 ka. Weak erosional-accumulative processes on the sill from 11.7 ka until the present favoured preservation of the iceberg ploughmarks. The predominant directions of the ploughmarks (north–south and northwest–southeast) coincide with the major iceberg (ice) drift direction from the Scandinavian ice sheet. Furrow width varies from 1 to 300 m with a main width of 20–60 m in a depth range of 1 to 10 m (mostly 2–4 m depth). The ploughmarks are flanked by side ridges 0.5–2 m high, and there is a push mound at the end of some furrows. Three types of cross-sectional furrow profiles have been distinguished: V-shaped cross-section profiles would have been formed by a peaked iceberg keel, U-shaped profiles by a flat keel, and W-shaped profiles by double-keel icebergs (ice ridges). The wide local depressions at the end of ploughmarks could have been formed during periods of fast falling of the Baltic Ice Lake water level, when the ice ridges (stamukhi) or icebergs could ground into the seafloor.

Paleotemperature, geochemical and grain size data in Quaternary sediments from the Gloria Drift (Northwest Atlantic)

Data file presents information on the variation in sea surface temperatures (SST), as well as geochemical (e.g. stable isotope, calcium carbonate), micropaleontological and grain size data from the Gloria Drift (Northwest Atlantic). The data are obtained from the three marine sediment gravity core sections (AMK-4493, AI-3646 and AI-3415) which were formed during Quaternary period. Dataset contains SST values (winter and summer: 0–50 water layer) and ice-rafted debris (IRD) counts, each in 308 samples; stable isotope data (δ18O and δ13C) from 235 samples; calcium carbonate content from 351 samples; relative abundance of polar species of planktonic foraminifera Neogloboquadrina pachyderma (sinistral) (Ehrenberg) in 51 samples, data of grain size analysis in bulk sediments (123 samples) and carbonate-free sediments (664). These data provide information about conditions of sedimentation at the Gloria Drift area.

Mineral Resources of the Kaliningrad Region

Mineral resources of the Kaliningrad Region are associated with the deposits of the platform cover: Paleozoic, oil, salt, and nonferrous and rare metals; Mesozoic, marls, limestones, and phosphorites; and Cenozoic, amber, brown coal, aggregates, peat, etc.

Contour currents of the North Atlantic during the last glacial cycle

The mean size of mineral particles of the 10–63 μm fraction (the so-called “sortable silt” mean size (

Recent sedimentation processes in the coastal zone of the Curonian Spit (Kaliningrad region, Baltic Sea)

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Holocene biogenic sediments of the Curonian Spit (south-eastern Baltic Sea coast)

)) was used as proxy for the variations in paleocurrent intensity. The modes of grain-size distribution were also examined. Sediments with bimodal grain size distribution (the second mode varies from 10 to 28 μm) correlate with the increased mean size of sortable silt (up to 18–23 μm) at the Hatton and Snorry Drifts. These parameters indicate an increase in bottom-current intensity during MIS 1, 3, and 5e. There is no correlation between grain-size distribution and climatic cyclicity of variations in contour-current intensity at the Gloria Drift. The similarity between AMK-4493 sediments and IRD-containing hemiturbidites of the Labrador Sea render doubtful the contourite nature of the Gloria Drift.