ALBERT

Description: Während des Spätpleistozäns und Holozäns werden auf der langgestreckten Sulu-See Tiefsee-Ebene Turbidite mit einer Häufigkeit von 3 bis 94 Ereignissen pro 1000 Jahre im Wechsel mit hemipelagischem Sediment abgelagert. Eine Tephralage und isotopenstratigraphische Untersuchungen ermöglichten es, 10 untersuchte Kolbenlotkerne zu korrelieren und in fünf bis ins letzte Hochglazial reichende Zeitscheiben zu gliedern. Entsprechend dem Gefüge der Basislagen der terrigenen Turbidite können im nördlichen Teil der Tiefsee-Ebene proximale und im Süden distale Ablagerungsbereiche unterschieden weren. Die Turbidithäufigkeiten bleiben bis ins Spätpleistozän konstant, nehmen jedoch regional von 94 Turbiditen/1000 Jahre im Norden auf 11 Turbidite/1000 Jahre im Südteil der Tiefsee-Ebene ab. Dieser Gradient und die Gefügemerkmale zeigen, daß die meisten Turbiditströme die Tiefsee-Ebene durch den sich nördlich anschließenden Panay-Canyon erreichen. Von allen berücksichtigten Faktoren ist der taifuninduzierte Einstrom dichterer Wassermassen aus dem Südchinesischen Meer durch die Mindoro-Straße und den Panay-Canyon der wahrscheinlichste Auslöser für hochfrequente terrigene Turbiditströme. A narrow deep-sea abyssal plain is situated in the deepest part of the south-eastern Sulu Sea subbasin. The trench sediments which were recovered with piston cores during RV Sonne cruises SO 49 and SO 58 comprise numerous Late Pleistocene to Holocene turbidites with intercalated hemipelagic mud layers. While a proximal turbidite facies is recognized only in the northern trench, distal terrigenous turbidites are frequent in the whole basin. The occurrence of calcareous turbidites is restricted, however, to the southern trench. Although terrigenous turbidite frequencies remain rather constant over the past 22,000 years, they show a decrease from 94 in the northern trench to 11 turbidites/ka in the southern part of the basin. This gradient points to the Panay Canyon north of the trench as the main source for terrigenous turbidites. Features of erosion and gravity-driven downslope-transport are observed on the Panay Canyon floor. From all factors considered, typhoon-induced water inflow from the South China Sea through the Mindoro Strait seems to be the most important trigger mechanism for the frequent release of terrigenous turbiditic flows passing through the Panay Canyon to the Sulu Sea abyssal plain.

Description: In der Schreibkreide von Helgoland (NW-Deutschland) wurden leitende Foraminiferenarten an einer Profiltraverse im Seegebiet südwestlich der Insel (Görtel) untersucht. Die Kenntnis der Lagerungsverhältnisse der Kreideschichten und der genauen Probenpositionen erlaubte unter Berücksichtigung der Bathymetrie die Konstruktion eines synthetischen Prof1les für die höhere Oberkreide (Unter-Coniac bis Ober-Santon) und die Festlegung der stratigraphischen Lage für die einzelnen Proben. Eine Aufstellung der Vertikalreichweiten leitender Arten führte zur Untergliederung in sechs Foraminiferen-Zonen, die bereits im Schreibkreide-Richtprofil von Lägerdarf/Holstein an der Makroinvertebraten-Gliederung geeicht wurden. Stark reduzierte Mächtigkeiten im Unter-Santon und aufgearbeitete Gehäuse von Stensioeina granulata polonica WITWICKA im Ober-Santonweisen in Verbindung mit Grobkreidelagen im Coniac und Ober-Santon auf wiederholte Erosionsphasen hin.

Description: The long-term climate cooling during Campanian - Maastrichtian times is not well understood to date, especially because of the uncertainty introduced by low temporal resolution of biostratigraphy and the pronounced provincialism between tropical and temperate taxa. Two new high-resolution carbon isotope records derived from the boreal shelf-sea section at Lägerdorf-Kronsmoor-Hemmoor, northern Germany and the tropical Pacific at Deep Sea Drilling Project Site 305, Shatsky Rise, reduce these uncertainties. The records can be correlated with an accuracy not achieved by biostratigraphic methods so far. Distinct carbon isotope events in the late Campanian and the early Maastrichtian can be identified at both localities suggesting to represent global carbon cycle perturbations. Especially, the negative carbon isotope excursion in the early Maastrichtian, a pronounced feature of open-ocean records from the Pacific and Southern oceans, is recognized for the first time at a shelf-sea locality related to the North Atlantic Ocean. Furthermore, two short-term positive excursions are identified as superimposed signals to this event. The improved stratigraphy provides the unique opportunity to recognize leads and lags between the carbon cycle and ocean circulation of different marine settings and ecosystems, leading to a better understanding of their causes and effects.

Description: Pleistocene and late Pliocene benthic foraminifera from the Manihiki Plateau (southwestern tropical Pacific) were studied at piston-core 34KL. A new benthic foraminiferal biozonation is proposed. It comprises the Nodogenerina sagriensis Partial Range Zone from core base to 566.5 cm and the Fissurina seminiformis Partial Range Zone from this level to core top. The boundary is defined by the last occurence of Nodogenerina sagriensis which is time equivalent to the ‘Stilostomella extinction’ in the Eastern Atlantic. High abundances of Cibicidoides wuellerstorfi indicate a strong influence of near-bottom currents. The absence of high-productivity sensitive species reveals a low flux of organic matter to the sea floor from which a considerable amount is adduced by lateral advection.

Description: Heavy metal pollution originating from anthropogenic sources like mining, industry and ship traffic is becoming an increasing threat for marine life. First evidences for human impacts on the heavy metal concentration in seawater were recorded in medieval times already. An emerging tool for palaeo-environmental applications is the heavy metal concentration in the tests of benthic foraminifera, which enable monitoring of the anthropogenic footprint on recent systems and the fossil record. The Helgoland mud area (HMA) in the German Bight is an important depositional area for fine sediments. Average sedimentation rates of up to 13 mm/yr offer high-resolution archives, which renders the site suitable for studying long-term variations of anthropogenic pollution on the marine system. The HMA also accumulates discharge from the Elbe and Weser rivers, which are affected by mining activities in their catchment areas since the Bronze Age. The concentration of chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), silver (Ag), tin (Sn) and lead (Pb) in tests of Ammonia batava was analysed along a sediment core from the HMA by laser ablation inductively coupled mass spectrometry (LA-ICP-MS). Radiocarbon datings and stable oxygen and carbon isotope stratigraphy revealed that the core is covering the Early Modern Period (~1550–1700 AD) and the post-World War II period (~1958–2009 AD). The basal unconformity of a tempestite depicts a hiatus and non-sequence between both periods ranging from 1700 to 1958 AD. The concentration of Cu, Zn, Ag and Pb was clearly elevated in the post-1950 AD part of the core indicating a markedly higher anthropogenic influence induced by industrialisation and rapid growth of cities since the 1950s. Variations in Cu, Zn, Ni, Ag and Pb concentrations were linked to mining activities and the production rates of Pb and Ag in the Harz Mountains. Redox-sensitive elements like Mn were correlated to storm surges resulting in the extensive reworking of sediment material. Therefore, the chemistry of the tests of A. batava reflects human activities and natural impacts at the same time, which allows its application for unravelling the environmental history of the North Sea and beyond.