Richard Waller | Keele University (original) (raw)
Papers by Richard Waller
… 2010, held 2-7 May …, 2010
The UK's Higher Education Academy Subject Centre for Geography, Earth and Environmental Scie... more The UK's Higher Education Academy Subject Centre for Geography, Earth and Environmental Sciences (GEES) is currently running a project entitledC-Change in GEES: Open licensing of climate change and sustainability resources in the Geography, Earth ...
The geomorphological processes operating within landscape systems result in the erosion, transpor... more The geomorphological processes operating within landscape systems result in the erosion, transport and deposition of significant quantities of sediment that can be preserved within a range of depositional landforms. The processes of sediment transport can result in the material acquiring a series of distinctive characteristics. Material deposited within a beach environment for example is well known for its highly rounded nature. These distinctive characteristics can be used to interpret the processes responsible for the deposition of sediments of unknown origin.
Proceedings of the 9th International Conference on Learning Analytics & Knowledge
The Cryosphere Discussions
Permafrost and Periglacial Processes
Journal of Glaciology
This paper examines the debris-rich basal ice layer from Worthington Glacier, Alaska, U.S.A., a s... more This paper examines the debris-rich basal ice layer from Worthington Glacier, Alaska, U.S.A., a small valley glacier overlying rigid bedrock. The debris-rich basal ice layer studied shows evidence for large-scale longitudinal compressive deformation (isoclinal folds and nappes), similar in style and magnitude features to that reported from push moraines formed in glacial sediments. The debris-rich ice largely comprisedstratified solid ice(layers of alternating debris-rich and debris-poor ice) which we suggest results from the tectonic attenuation of folds produced from the deformation of the frozen debris, glacier ice and bubble-rich ice that comprise the initial basal layer of Worthington Glacier. Beneath the glacier lies a thin bed of saturated diamicton which contains evidence of limited movement. It is suggested that this is the result of the partial melt-out of the debris-rich basal ice layer which then behaved as a local (and seasonal) thin deforming layer.It is suggested that...
Glacier Science and Environmental Change, 2006
Recent advances in our understanding of glacier-permafrost interactions provide an alternative hy... more Recent advances in our understanding of glacier-permafrost interactions provide an alternative hypothesis to interpret Pleistocene glaciotectonic sequences in regions where permafrost no longer exists. Instead of necessarily forming under unfrozen subglacial conditions, some glaciotectonic sequences may have formed by submarginal deformation of warm, partially-frozen permafrost. An example from North Norfolk, U.K., suggests that an ice sheet during Marine Isotope Stage 12 advanced across permafrost terrain, deforming it beneath the margin. Such a scenario can help explain some features whose formation under unfrozen conditions is problematic, including (1) the substantial thickness of the deforming layer and (2) the preservation of stratified intraclasts. Accordingly, glacial geologists should remain open to the possibility of glacier-permafrost interactions when interpreting glacigenic sequences. Such a re-interpretation could have major implications for reconstructing basal thermal regimes and modeling palaeo-ice sheets.
Sedimentary Geology, 2012
Sedimentary Geology, 2004
Quaternary Science Reviews, 2005
Quaternary International, 2001
Quaternary International, 2012
Proceedings of the Geologists' Association, 2009
ABSTRACT Recent work in modern and ancient glacial environments has demonstrated the ability of c... more ABSTRACT Recent work in modern and ancient glacial environments has demonstrated the ability of cold-based glaciers to interact with permafrost. Geological evidence for glacier–permafrost interactions is revealed in Arctic regions where permafrost has persisted since deglaciation. Whilst similar interactions probably occurred near the margins of former ice sheets in the mid-latitudes, this interpretation is rarely applied to unfrozen glacigenic sequences. This review considers the extent to which this alternative hypothesis can explain two key aspects of the glaciotectonic sequences of North Norfolk that have traditionally been attributed to the deformation of unfrozen sediment. The substantial thickness (>10m) of the pervasively deformed sequences and the preservation of stratified sand intraclasts within them are consistent with deformation at temperatures slightly below the pressure melting point (warm permafrost). Such deformation is also consistent with the pre-glacial environment, which was characterised by continuous permafrost. The hypothesis of deformation at sub-freezing temperatures should be considered more widely when interpreting glaciotectonically deformed, ice-marginal sequences in the mid-latitudes. The application of geological evidence to reconstruct basal thermal regimes beneath former glaciers would complement existing geomorphological inverse models and provide additional information to improve the parameterisation of subglacial processes in numerical ice-sheet models.
Journal of Glaciology, 2004
The upper 20—30 m of ice-rich permafrost at three sites overridden by the northwest margin of the... more The upper 20—30 m of ice-rich permafrost at three sites overridden by the northwest margin of the Laurentide ice sheet in the Tuktoyaktuk Coastlands, western Arctic Canada, comprise massive ice beneath ice-rich diamicton or sandy silt. The diamicton and silt contain (1) truncated ice blocks up to 15 m long, (2) sand lenses and layers, (3) ice veins dipping at 20—30°, (4) ice lenses adjacent and parallel to sedimentary contacts, and (5) ice wedges. The massive ice is interpreted as intrasedimental or buried basal glacier ice, and the diamicton and silt as glacitectonite that has never thawed. Deformation of frozen ground was mainly ductile in character. Deformation was accompanied by sub-marginal erosion of permafrost, which formed an angular unconformity along the top of the massive ice and supplied ice clasts and sand bodies to the overlying glacitectonite. After deformation and erosion ceased, postglacial segregated ice and ice- wedge ice developed within the deformed permafrost.
Geological Society, London, Special Publications, 2005
This paper describes the key characteristics of a proglacial moraine complex at the Leverett Glac... more This paper describes the key characteristics of a proglacial moraine complex at the Leverett Glacier, western Greenland. The presence of a large stream-cut exposure allowed the examination of its internal structure, as well as its surface geomorphology. It is composed of a variety of ice and sediment facies, including debris-poor ice, ice-rich diamicton and ice-rich gravel. These units are glaciotectonized, with the exposure featuring a major fault and associated drag fold, a planar, erosional unconformity, and a variety of small-scale folds. Various interpretations are considered, including the possibility that the sequence represents a buried basal ice layer. However, it is argued that the structural characteristics are best explained by a two-phase model involving ice advance and proglacial or ice-marginal compression, followed by overriding and subglacial deformation and erosion, tentatively related to ice advance after the Holocene Hypsithermal (c. 4900–3000 calendar years bp)....
… 2010, held 2-7 May …, 2010
The UK's Higher Education Academy Subject Centre for Geography, Earth and Environmental Scie... more The UK's Higher Education Academy Subject Centre for Geography, Earth and Environmental Sciences (GEES) is currently running a project entitledC-Change in GEES: Open licensing of climate change and sustainability resources in the Geography, Earth ...
The geomorphological processes operating within landscape systems result in the erosion, transpor... more The geomorphological processes operating within landscape systems result in the erosion, transport and deposition of significant quantities of sediment that can be preserved within a range of depositional landforms. The processes of sediment transport can result in the material acquiring a series of distinctive characteristics. Material deposited within a beach environment for example is well known for its highly rounded nature. These distinctive characteristics can be used to interpret the processes responsible for the deposition of sediments of unknown origin.
Proceedings of the 9th International Conference on Learning Analytics & Knowledge
The Cryosphere Discussions
Permafrost and Periglacial Processes
Journal of Glaciology
This paper examines the debris-rich basal ice layer from Worthington Glacier, Alaska, U.S.A., a s... more This paper examines the debris-rich basal ice layer from Worthington Glacier, Alaska, U.S.A., a small valley glacier overlying rigid bedrock. The debris-rich basal ice layer studied shows evidence for large-scale longitudinal compressive deformation (isoclinal folds and nappes), similar in style and magnitude features to that reported from push moraines formed in glacial sediments. The debris-rich ice largely comprisedstratified solid ice(layers of alternating debris-rich and debris-poor ice) which we suggest results from the tectonic attenuation of folds produced from the deformation of the frozen debris, glacier ice and bubble-rich ice that comprise the initial basal layer of Worthington Glacier. Beneath the glacier lies a thin bed of saturated diamicton which contains evidence of limited movement. It is suggested that this is the result of the partial melt-out of the debris-rich basal ice layer which then behaved as a local (and seasonal) thin deforming layer.It is suggested that...
Glacier Science and Environmental Change, 2006
Recent advances in our understanding of glacier-permafrost interactions provide an alternative hy... more Recent advances in our understanding of glacier-permafrost interactions provide an alternative hypothesis to interpret Pleistocene glaciotectonic sequences in regions where permafrost no longer exists. Instead of necessarily forming under unfrozen subglacial conditions, some glaciotectonic sequences may have formed by submarginal deformation of warm, partially-frozen permafrost. An example from North Norfolk, U.K., suggests that an ice sheet during Marine Isotope Stage 12 advanced across permafrost terrain, deforming it beneath the margin. Such a scenario can help explain some features whose formation under unfrozen conditions is problematic, including (1) the substantial thickness of the deforming layer and (2) the preservation of stratified intraclasts. Accordingly, glacial geologists should remain open to the possibility of glacier-permafrost interactions when interpreting glacigenic sequences. Such a re-interpretation could have major implications for reconstructing basal thermal regimes and modeling palaeo-ice sheets.
Sedimentary Geology, 2012
Sedimentary Geology, 2004
Quaternary Science Reviews, 2005
Quaternary International, 2001
Quaternary International, 2012
Proceedings of the Geologists' Association, 2009
ABSTRACT Recent work in modern and ancient glacial environments has demonstrated the ability of c... more ABSTRACT Recent work in modern and ancient glacial environments has demonstrated the ability of cold-based glaciers to interact with permafrost. Geological evidence for glacier–permafrost interactions is revealed in Arctic regions where permafrost has persisted since deglaciation. Whilst similar interactions probably occurred near the margins of former ice sheets in the mid-latitudes, this interpretation is rarely applied to unfrozen glacigenic sequences. This review considers the extent to which this alternative hypothesis can explain two key aspects of the glaciotectonic sequences of North Norfolk that have traditionally been attributed to the deformation of unfrozen sediment. The substantial thickness (>10m) of the pervasively deformed sequences and the preservation of stratified sand intraclasts within them are consistent with deformation at temperatures slightly below the pressure melting point (warm permafrost). Such deformation is also consistent with the pre-glacial environment, which was characterised by continuous permafrost. The hypothesis of deformation at sub-freezing temperatures should be considered more widely when interpreting glaciotectonically deformed, ice-marginal sequences in the mid-latitudes. The application of geological evidence to reconstruct basal thermal regimes beneath former glaciers would complement existing geomorphological inverse models and provide additional information to improve the parameterisation of subglacial processes in numerical ice-sheet models.
Journal of Glaciology, 2004
The upper 20—30 m of ice-rich permafrost at three sites overridden by the northwest margin of the... more The upper 20—30 m of ice-rich permafrost at three sites overridden by the northwest margin of the Laurentide ice sheet in the Tuktoyaktuk Coastlands, western Arctic Canada, comprise massive ice beneath ice-rich diamicton or sandy silt. The diamicton and silt contain (1) truncated ice blocks up to 15 m long, (2) sand lenses and layers, (3) ice veins dipping at 20—30°, (4) ice lenses adjacent and parallel to sedimentary contacts, and (5) ice wedges. The massive ice is interpreted as intrasedimental or buried basal glacier ice, and the diamicton and silt as glacitectonite that has never thawed. Deformation of frozen ground was mainly ductile in character. Deformation was accompanied by sub-marginal erosion of permafrost, which formed an angular unconformity along the top of the massive ice and supplied ice clasts and sand bodies to the overlying glacitectonite. After deformation and erosion ceased, postglacial segregated ice and ice- wedge ice developed within the deformed permafrost.
Geological Society, London, Special Publications, 2005
This paper describes the key characteristics of a proglacial moraine complex at the Leverett Glac... more This paper describes the key characteristics of a proglacial moraine complex at the Leverett Glacier, western Greenland. The presence of a large stream-cut exposure allowed the examination of its internal structure, as well as its surface geomorphology. It is composed of a variety of ice and sediment facies, including debris-poor ice, ice-rich diamicton and ice-rich gravel. These units are glaciotectonized, with the exposure featuring a major fault and associated drag fold, a planar, erosional unconformity, and a variety of small-scale folds. Various interpretations are considered, including the possibility that the sequence represents a buried basal ice layer. However, it is argued that the structural characteristics are best explained by a two-phase model involving ice advance and proglacial or ice-marginal compression, followed by overriding and subglacial deformation and erosion, tentatively related to ice advance after the Holocene Hypsithermal (c. 4900–3000 calendar years bp)....