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ABSTRACT Fjords commonly hold sediment basins with high temporal resolution that mirror land- and marine-based processes and depositional environments during a glacial-interglacial cycle. Here, we present TOPAS seismic profiles, with a vertical resolution of <30 cm, bathymetric records and a gravity core from Fensfjorden, west Norway, which allow a detailed study of sedimentary processes and depositional environments in a NE Atlantic fjord system. Fensfjorden hosts a sediment volume of 0.70 km3 and the sediment basins evolved reach a maximum thickness of 100 m. The basins are characterized by a lower acoustically well-laminated glacimarine unit, of Allerød and Younger Dryas age. This unit is overlain by several acoustically transparent lenses, interpreted to be slide debrites. We suggest these slide debrites to be a result of recurrent mass failures that occurred between 11 500 and 2100 cal a BP. A thin late Holocene hemipelagic unit drapes the slide debrites. During the late Holocene the sedimentation rates in Fensfjorden decreased from 0.110 to 0.040 cm a−1 and two turbidity currents occurred in the 2040-1190 cal a BP time period. This ability to map fjord processes in more detail has, furthermore, made it possible to revise the established stratigraphical framework for NE Atlantic fjords. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Basin water in deep-silled Norwegian fjords is primarily influenced by inflowing Atlantic water originating from the Norwegian Atlantic Current (NwAC). Previous studies suggest that benthic foraminiferal oxygen isotope records from such fjords are strongly influenced by variability in this current. The present paper presents a mid- to late-Holocene record (6–2.2 ka) with 17-yr time resolution from a western Norwegian deep-silled fjord, Voldafjorden. An age model, based on ten AMS radiocarbon dates on marine carbonates and on one plant macrofossil, has been established. The study focuses on the oxygen isotope results, obtained from two species of benthic foraminifera: Cassidulina laevigata and Uvigerina mediterranea. The δ18O C. laevigata record has systematically larger amplitudes than the δ18O U. mediterranea record, which most likely is related to different life cycles/periods of calcification. The oxygen isotope results show a clear shift towards higher values between 5 and 4 ka, interpreted to reflect a temperature drop in the basin water of c. 1°C. After the temperature drop, the high frequency variability (centennial and multidecadal) changes abruptly towards larger amplitudes. This corresponds to changes in subperiodicity, where a 370 year cycle in the δ18O C. laevigata record disappears after 3.8 ka. The δ18O transition corresponds to changes in carbon isotopes and grain size distribution, suggesting that a more extensive change in the fjord environment occurred after the cooling. The timing of the oxygen isotope shift towards higher values and the transition in high frequency variability correspond to major changes recorded in paleoclimate archives within the North Atlantic region and globally. [ABSTRACT FROM AUTHOR]