Glacitectonics – a key approach to examining ice dynamics, substrate rheology and ice-bed coupling

Abstract

Lee, J.R. and Phillips, E. 2013. Glacitectonics -a key approach to examining ice dynamics, substrate rheology and ice-bed coupling. Proceedings of the Geologists ' Association, 124,[731][732][733][734][735][736][737] AbstractThe role of ice masses within the Earth's climate system and in landscape change is increasingly being recognised within regions that are either currently glaciated or were glaciated during the geological past. There are many different remote and field-based approaches to studying the products of glaciation. One approach -that of glacitectonics, focuses on the styles of deformation and tectonic imprint (folds, fractures, fabrics, foliations and lineations) produced as ice overrides or pushes into pre-existing rocks or sediment. This approach, when used in combination with other types of evidence, can be used to infer ice-dynamics, substrate rheology and ice-bed coupling. Of equal significance is the influence of glacitectonic structure upon the applied properties of glaciated terranes such as ground stability, hydrogeology and fluid migration (e.g. water, gas hydrates and hydrocarbons). This paper provides an introduction to this Special Issue on Glacitectonics, outlining the significance and historical development of this field of glacial geology, before introducing and summarising the contributions that make up the volume.

Repeated advance and retreat of the East Antarctic Ice Sheet on the continental shelf during the early Pliocene warm period

“…Therefore, it is more likely that the apparent dip of the laminae has been caused by post-depositional glacitectonic effects due to the numerous glacial cycles that would have overrun the area up until the Last Glacial Maximum. Glacitectonism is a common feature of sediments deposited on previously glaciated shelves and is caused by overriding ice deforming underlying substrate (Lee and Phillips, 2013). It is likely that the rare deformation structures in facies 1c probably relate to post-depositional processes such as loading causing grain stacks (Fig.…”

Architecture and structural evolution of an early Little Ice Age terminal moraine at the surge‐type glacier Múlajökull, Iceland

“…Glaciotectonic processes are generally recognized as playing a significant role in glacier dynamics and the development of complex glaciogenic sequences and landforms [ Aber et al ., ; Aber and Ber , ; Lee and Phillips , ; Pedersen , ]. In order to shed light on glaciotectonic processes during surges and to provide modern analogues to glaciotectonic landforms produced by Pleistocene ice sheets, end moraines of surge‐type glaciers have received a significant amount of research interest [e.g., Croot , ; Huddart and Hambrey , ; Boulton et al ., ; Benediktsson et al ., , , ; Benediktsson , ].…”

Plio‐Pleistocene fault reactivation within the Crag Basin, eastern UK: implications for structural controls of landscape development within an intraplate setting

“…However, this justification is ambiguous given that the glaciotectonic origin of the sequence at High Lodge is long‐established (Ashton et al . 1992) and stratigraphical inversion is a common structural feature of glaciotectonized sequences (Lee & Phillips 2013 and references therein).…”