ICE MARGIN TERRESTRIAL LAND SYSTEMS: SUB POLAR GLACIER MARGINS OF THE CANADIAN AND GREENLAND HIGH ARCTIC

Glacial Geology and Geomorphology

Glacitechtonic landforms

Impressive landforms produced at the margin of sub-polar glacier of the Canadian and Greenland Arctic – Thrust Block Moraines or composite ridges produced by proglacial disturbance of glacilacustrine, raised glacimerine or glacifluvial sediments on valley floor

Axel Heiberg Island

Concidence of Thrust-block moraine and former deep-sea sedimes or low altitude – significant se level dring construction

Hook Glacier, Makinson inlet, Ellesmere Island – example of proglacial thrust on existing delta.

Glacial Debris release Process and Moraine Deposition

Exposure of complex debris rich basal ice with intense folds and thrusts – construction of tranverse septa – controls pattern of differential ablation, meltwater flow, sediment reworking

Margins of Ice fields and upland outlet Glaciers associated with plateau – debris turnover is low and moraines are rare

Glacier recession in Canadian Arctic – documented by occurance of flow lines of boulders and assocated rubble veneers that form conspicuous trimlines – Dobbin Bay, Ellesmere Island

Glacifluvial Process and forms

Rock Glacieration

Piedmont or tongued shaped rock glaciers – at the base of cirque or valley floor

Talus foot rock glacier – employed in the reconstruction of former glacier margins where they thought to represent rock glacerized lateral moraines

Ice-contact Glacimarine and Glacilacustrine Landforms

Grounding line-fans – sediment laden meltwater enters deep water from englacial or subglacial

Modern outlet glacier – produce subglacial meltwater

Sparce glacimarine sdiments between pinning points – rapid glacier retreat

Meltwater deposits formed by settling of suspended sedimets frim turbid overflow plumes – grounding line fans

Subaqeous morainal banks (transverse elongate landforms along ground lines) – intervals of glacier terminus stability

Elongate morphology of morainal banks – their origin by deposition from a series of point sources along the ice front and ice marginal fluctuations athat act to bulldoze and squeeze sediment along groundline

Arctic deltas – tripartite internal structure – topset, foreset, bottomset

	GLACIAL LANDFORM	LOCATION
Ice margin terrestrial land systems: sub polar glacier margins of the Canadian and Greenland high arctic	Marginal supraglacial ramp with its extensive supraglacial debris cover	Inner Dobbin Bay, Eastern Ellesmere Island
	Cliff Margin of sub-polar Glacier showing debris rich basal ice facies and apron of dry calved ice blocks and debris	Philips Inlet, Northwest Ellesmere Island
	Thrustblock Moraine incised by proglacial meltwater channels	Axel Heiberg Island
	Holocene ice-contact delta with proglacial thrust	Hook Glacier, Makinson Inlet
	Controlled moraine ridges super imposed on the inner blocks of a thrust block moraine	Eugenie Glacier, Dobbin Bay, Ellesmere Island
	Trimline moraine comprising of line of boulders and weakly developed moraine ridge	Dobbin Bay, eastern Ellesmere Island
	Low Gradient lateral Meltwater channels, retreat of fjord glacier	Blind Fjord, Ellesmere Island
	Glacier Ice buried by talus	Dobbin Bay, eastern Ellesmere Island
	Arcuate Morainal bank inset	Ellesmere Island
	Braided outwash plain entering sea	Ellesmere Island
	Ice dammed lake produced by the blocking of a valley by a plateau-outlet glacier	Viking Ice Cap, Northeastern Ellesmer Island

SOURCE:

GLACIAL LANDSYSTEMS
DAVID J. ADAMS

Thrust Block Moraines