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Glaciofluvial – periglacial deposits

Terminal moraines and outwash braidplain ahead of a retreating Strand Glacier, Axel Heiberg Island, as it was in 1983.
Terminal moraines and outwash braidplain ahead of a retreating Strand Glacier, Axel Heiberg Island, as it was in 1983.

The glaciofluvial-periglacial category refers to pretty well anything sedimentological, that is associated with glaciations, glaciers, ice caps, and ice sheets. It includes the ice itself, outwash sediment in fluvial and lacustrine environments, and ice-related phenomena like permafrost and patterned ground.  Most of my examples are from Canada, the Arctic, and Laurentide Icesheet locations like Ottawa, Ontario, and Fraser Lowlands, British Columbia.

Part of the Strand Glacier terminal moraine, the meltwater, and outwash channels. Sediment on top of the glacier has been concentrated by ablation. The outwash channel in the foreground is fed by a subglacial stream. The sediment eventually finds its way to Strand Fiord as a fan delta.
Part of the Strand Glacier terminal moraine, the meltwater, and outwash channels. Sediment on top of the glacier has been concentrated by ablation. The outwash channel in the foreground is fed by a subglacial stream. The sediment eventually finds its way to Strand Fiord as a fan delta.
Mixed sediment and ice at the snout of Strand Glacier, Axel Heiberg Island, concentrated by ablation and melting. Mechanical sorting of sediment only begins in the outwash fan.
Mixed sediment and ice at the snout of Strand Glacier, Axel Heiberg Island, concentrated by ablation and melting. Mechanical sorting of sediment only begins in the outwash fan.
The edge of Muller Ice Cap on central Axel Heiberg Island, eroded by the outwash stream. Deformation of ice is accentuated by dark mud and sand in the ice (clear ice lies above the darker foundation. Ice rheology here includes ductile and brittle deformation. The lower sediment-rich section is about 4.5 m thick
The edge of Muller Ice Cap on central Axel Heiberg Island, eroded by the outwash stream. Deformation of ice is accentuated by dark mud and sand in the ice (clear ice lies above the darker foundation. Ice rheology here includes ductile and brittle deformation. The lower sediment-rich section is about 4.5 m thick
Aerial view of the ice cap edge shown in the image above.
Aerial view of the ice cap edge shown in the image above.
Lateral moraine and crevasses at the Valley of the Six Glaciers, Lake Louise, Alberta. Glacier flow is to the left.
Lateral moraine and crevasses at the Valley of the Six Glaciers, Lake Louise, Alberta. Glacier flow is to the left.
A beautiful U-shaped valley at Glen Rosa, Arran (Scotland), gouged by a glacier during the Last Ice Age.
A beautiful U-shaped valley at Glen Rosa, Arran (Scotland), gouged by a glacier during the Last Ice Age.
Late Pleistocene, crossbedded glacial outwash channel deposits; the channel base is lined with boulders. Bradner Road pit, Fraser Valley
Late Pleistocene, crossbedded glacial outwash channel deposits; the channel base is lined with boulders.  Bradner Road pit, Fraser Valley
Detail of trough crossbeds and multiple bedform truncations in a glacial outwash channel, Stokes pit, Fraser Valley, British Columbia.
Detail of trough crossbeds and multiple bedform truncations in a glacial outwash channel, Stokes pit, Fraser Valley, British Columbia.
Large foresets (4-5m thick) in glacial outwash, may have formed as a small Gilbert-type delta in an outwash lake of meltwater pond.  The overlying topset sand is about 1.5m thick, that, in turn was overridden by a diamictite during ice advance. Bradner Road pit, Fraser Valley.
Large foresets (4-5m thick) in glacial outwash, may have formed as a small Gilbert-type delta in an outwash lake of meltwater pond.  The overlying topset sand is about 1.5m thick, that, in turn was overridden by a diamictite during ice advance. Bradner Road pit, Fraser Valley.
A complex array of trough and planar crossbeds in Late Pleistocene glacial outwash channels. Bradner Road pit, Fraser Valley.
A complex array of trough and planar crossbeds in Late Pleistocene glacial outwash channels. Bradner Road pit, Fraser Valley.
Glacial outwash channel deposits deformed by ice loading. Deformation took place in slump packages and along small faults.
Glacial outwash channel deposits deformed by ice loading. Deformation took place in slump packages and along small faults.
Ice-contact deformation of outwash gravels, detachment and rotation of a large block of semi-consolidated sand. 8th Avenue pit, Fraser Valley.
Ice-contact deformation of outwash gravels, detachment and rotation of a large block of semi-consolidated sand. 8th Avenue pit, Fraser Valley.
Ice-contact deformation of outwash sands along small listric faults, that appear to detach at the contact with pebbly sand below. Field note book for scale. Bradner Road pit.
Ice-contact deformation of outwash sands along small listric faults, that appear to detach at the contact with pebbly sand below. Field note book for scale. Bradner Road pit.
Crossbedded and rippled glacial outwash in a gravel pit at Kanata, Ottawa. Arrows point to small thrust faults (movement to the left) probably caused by ice loading prior to deposition of the thicker crossbedded unit above (the faults do not extend into the overlying unit).
Crossbedded and rippled glacial outwash in a gravel pit at Kanata, Ottawa. Arrows point to small thrust faults (movement to the left) probably caused by ice loading prior to deposition of the thicker crossbedded unit above (the faults do not extend into the overlying unit).
Thick trough crossbeds in an outwash channel, Kanata, Ottawa. The channel seems to have been filled by at least three stages of sediment influx, and scouring of the channel floor.
Thick trough crossbeds in an outwash channel, Kanata, Ottawa. The channel seems to have been filled by at least three stages of sediment influx, and scouring of the channel floor.
Outwash sand, deposited in large migrating dunes (upper half of outcrop), and multiple sets of climbing ripples (about level with the geologist). The topmost layer contains sandy muds folded and contorted by ice loading. Kanata, Ottawa
Outwash sand, deposited in large migrating dunes (upper half of outcrop), and multiple sets of climbing ripples (about level with the geologist). The topmost layer contains sandy muds folded and contorted by ice loading. Kanata, Ottawa
In-phase (supercritical) climbing ripples in the lower part of this outcrop pass upwards to more laminated fine-grained sands where ripples are barely evident. Late Pleistocene glaciofluvial deposits near Vancouver, Canada.
In-phase (supercritical) climbing ripples in the lower part of this outcrop pass upwards to more laminated fine-grained sands where ripples are barely evident. Late Pleistocene glaciofluvial deposits near Vancouver, Canada.
Kink folds in semi-consolidated outwash sand, formed during ice-contact, Kanata, Ottawa
Kink folds in semi-consolidated outwash sand, formed during ice-contact, Kanata, Ottawa
Glacial striae on greywacke; scratches formed as rock fragments are dragged across the bedrock surface by flowing ice during the Last Glaciation (Laurentide Icesheet).
Glacial striae on greywacke; scratches formed as rock fragments are dragged across the bedrock surface by flowing ice during the Last Glaciation (Laurentide Icesheet).
Frost heaved blocks of greywacke; the polygonal cross-sections of the blocks is governed by intersecting fractures in the bedrock. Belcher Islands.
Frost heaved blocks of greywacke; the polygonal cross-sections of the blocks is governed by intersecting fractures in the bedrock. Belcher Islands.
Deformed ground ice within the permafrost, probably caused by ice expansion. The trees above are 3-4m high. The ice fold was exposed in the slip face of a thermokarst slump. North Yukon.
Deformed ground ice within the permafrost, probably caused by ice expansion.  The trees above are 3-4m high. The ice fold was exposed in the slip face of a thermokarst slump. North Yukon.
Thermokarst slumping, caused by shallow melting permafrost soils and subsoils
Thermokarst slumping, caused by shallow melting permafrost soils and subsoils
Exposed permafrost - frozen soil, north Yukon.
Exposed permafrost – frozen soil, north Yukon.
Arctic soils riven with permafrost. Left: Typical patterned ground developed on Arctic permafrost. The hummocks are generally less than a metre wide; their tops are vegetated.
Arctic soils riven with permafrost. Left: Typical patterned ground developed on Arctic permafrost. The hummocks are generally less than a metre wide; their tops are vegetated.

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