Criteria to distinguish between subglacial glaciotectonic and glaciomarine sedimentation, I. Deformation styles and sedimentology

Abstract

This paper compares and contrasts the sedimentology and structural geology of a Quaternary glaciomarine site (Melabakkar-Ásbakkar, Iceland) and a Quaternary subglacial glaciotectonic site (West Runton, UK). Research suggests that the glaciomarine environment is dominated by sedimentary processes, related to sediment supply, water content and distance from the glacier margin. Glaciotectonic deformation, however, is dominated by deformational processes, related to effective pressure, shear strain, nature of the subglacial material and distance from the glacier margin. From this study a series of criteria are suggested to distinguish both Quaternary and contemporary glaciotectonic and glaciomarine environments. In addition, the paper also discusses the subsequent effects of glaciotectonic deformation on a primary glaciomarine site due to a glacial readvance.