An introduction to glaciated margins: the sedimentary and geophysical archive

A glaciated margin is a continental margin that has been occupied by a large ice mass, such that glacial processes and slope processes conspire to produce a thick sedimentary record. Ice masses take an active role in sculpting, redistributing and reorganizing the sediment that they erode on the continental shelf, and act as a supply route to large fan systems (e.g. trough mouth fans, submarine fans) on the continental slope and continental rise. To many researchers, the term ‘glaciated margin’ is synonymous with modern day areas fringing Antarctica and the Arctic shelf systems, yet the geological record contains ancient examples ranging in age from Precambrian to Cenozoic. In the pre-Pleistocene record, there is a tendency for the configuration of the tectonic plates to become increasingly obscure with age. For instance, in the Neoproterozoic record, not everyone agrees on the location of rift margins and some fundamental continental boundaries remain unclear. Given these issues, this introductory paper has two simple aims: (1) to provide a brief commentary of relevant Geological Society publications on glaciated margins, with the landmark papers highlighted and (2) to explain the contents of this volume.

Glaciated margins occur in modern and ancient high-latitude settings and record the growth and recession of ice masses over continental shelves, slopes and rises. They are commonly assumed to be passive continental margins with a glacial overprint, but can equally encompass more active tectonic settings such as rift basins. The processes of ice sheet sculpting (to produce characteristic subglacial bedforms), sediment erosion and transport, and widespread and extensive sediment deposition (most spectacularly on continental slopes) all play a part. Such margins are of widespread interest to an interdisciplinary group of earth scientists. These range from geomorphologists and geophysicists focused on using subglacial landforms to produce ice sheet reconstructions, geologists with similar goals using sediment architecture, and to those interested in resource prospecting, notably hydrocarbon exploration. This volume aims to showcase a cross-section of research on glaciated margins from the very ancient (Cryogenian) to the present day. The hope is that through the long lens of the geological record, research on modern glaciated margins can take lessons from the ancient record and vice versa.