Features of sedimentation in the Gren-fjord (West Spitsbergen)

Sedimentation in gulfs of the Arctic fjord type is very specific and different from gulfs of moderate and southern latitudes. In this aspect, sedimentation in the Gren-fjord is remarkable due to a set of features. Results of the Gren-fjord gulf (West Spitsbergen) researches have been presented in the work. This paper is based on field work materials obtained in 2014-2016. The aim of the work in the Gren-fjord Gulf was to study sedimentation characteristics in sedimentation basin. Eight sections have been made to reach the goal: three in the inner part of the bay (perpendicular to the coast), one longitudinal section (along the axis of the bay) and four in the intertidal zone in the outer portion of the bay. In general, 17 sediment samples and 17 samples of surface sediment layer in the intertidal zone for selected sections have been made. Van Vin and Petersen bottom grabs have been used for sampling. Location of stations has been chosen in view of geomorphology and bottom configuration of the bay. In order to determine sedimentation mechanism three ground columns have been selected in the region, the exposed sediment thickness is up to 104 cm. Hand percussion drilling has been applied for cores. The gravel-pebble material with inequigranular sand admixture has been found in the intertidal zone during the works. Fine-grained material is accumulated seaward. Granulometric composition at watercourses mouths varies with distance. The estuary area of the Grondalen River as well as the Warming and Larvik bays has increased percentage of silt-pelitic material. Mainly silt-pelitic material is accumulated in the inner part of the bay along the axis, but percentage of gravel-pebble material in the outer part of the bay increases significantly. The exposed thickness of sediment column is characterized by a layered texture. Layers differ from each other in thickness, color, density, bedding plane, the contact with higher and lower horizons, particle size distribution, organic matter content and various inclusions, the degree of constituent grains rounding.