Methodology:

A 2 m-long sediment core was recovered with a UWITEC KOL 'Kolbenlot' percussion piston corer to a total sediment depth of 5.24 m (LC12) in Blaso (LC12: 90 m water depth; 79.5948 degrees N, 22.44233 degrees E).

Physical properties (magnetic susceptibility, wet bulk density) were measured on whole core using a GEOTEK multi-sensor core logger (MSCL) at the Department of Geography, Durham University, to characterise lithological properties and infer the depositional environment(s). Core sections were then split, described and sub-sampled. 1-cm thick sediment slices were taken every 10-20 cm. Grain-size analyses was performed on core LC12 using a Beckman Coulter LS 13 320 Laser Diffraction particle size analyser. Prior to analysis sediment samples were treated with 20 percent hydrogen peroxide to digest the organic material.

A total of 6 (LC7) samples were processed for foraminiferal analysis to reconstruct the environmental conditions in Blaso. Sample volume varied between 0.5 and 5 ml (cm3) depending on average foraminiferal concentration (estimated based on initial scanning of samples). The variation in sample size was designed to allow ~300 to 500 specimens to be counted from all samples. Once extracted samples were soaked in deionized water for several hours to help disaggregate the sediment. Samples were then washed through a 500 micrometer and 63 micrometer mesh sieve to concentrate the foraminifera. The material collected on the 63 μm mesh sieve were retained for foraminiferal analysis. Foraminifera were identified and counted from the wet residue under a binocular microscope.

Data collection:

UWITEC KOL 'Kolbenlot' percussion piston corer

GEOTEK multi-sensor core logger

Binocular microscope

Beckman Coulter LS 13 320 Laser Diffraction particle size analyser