Sedimentary environment, lithostratigraphy and dating of sediment sequences from Arctic lakes Revvatnet and Svartvatnet in Hornsund, Svalbard

Abstract

Abstract The sedimentary environment, sediment characteristics and age-depth models of sediment sequences from Arctic lakes Revvatnet and Svartvatnet, located near the Polish Polar Station in Hornsund, southern Svalbard (77°N), were studied with a view to establishing a basis for paleolimnological climate and environmental reconstructions. The results indicate that catchment-to-lake hydroclimatic processes probably affect the transportation, distribution and accumulation of sediments in different parts of lakes Revvatnet and Svartvatnet. Locations with continuous and essentially stable sedimentary environments were found in both lakes between water depths of 9 and 26 m. We used several different dating techniques, including 137Cs, 210Pb, AMS 14C, and paleomagnetic dating, to provide accurate and secured sediment chronologies. Arecovered sequence from the northern basin of Revvatnet spans more than one thousand years long with laminated stratigraphy in the upper part of the sediment. Based on AMS 14C dates, it is possible to suppose that Revvatnet basin was not occupied by a valley glacier during the Little Ice Age. The dates were supported by 137Cs chronologies, but not confirmed with other independent dating methods that extent beyond the last 50 years. A sedimentary sequence from the northern basin of Svartvatnet provides a potential archive for the study of climate and environmental change for the last ca. 5000 years. Based on the stratigraphy and a Bayesian age-depth model of AMS14C and paleosecular variation (PSV) dates, the recovered sediment sections represent a continuous and stable sedimentation for the latter half of the Holocene.