Differentiation of glacial and volcanic sedimentation environments on Deception Island (South Shetland Island, Antarctica)

Abstract

The islands of the South Shetland archipelago present rapid environmental changes resulting from climatic conditions, promoted by regional warming registered in recent decades. Deception Island, located in the archipelago, is the southernmost of the South Shetland Islands and contains the largest active volcano in Maritime Antarctica. The last subglacial eruptions that occurred between 1969 and 1970 affected the mass balance of local glaciers. This study sought evidence of environmental processes on Deception Island through sedimentological analysis and measurements of physical properties in marine sedimentary cores. The results of the sediments referring to the submerged volcanic cone Ferraz Peak indicate the predominant granulometry in sandy silt that differed from the other areas that predominate in clayey silt. The magnetic susceptibility parameter suggests values ​​of distinction between sedimentation of volcanic origin (>150 SI x 10^-5), marine and glacial (< 120 SI x 10^-5). Geochemical data showed higher Fe-Mn contents that suggest underwater hydrothermal mineralization in the sediments of the Ferraz Peak volcanic cone. Electrical resistivity was inversely proportional to gamma density, ensuring the reliability of MSCL data to analyze sedimentary patterns from Deception Island, which could provide more effective provenance methods.