Directions of ice flow during the last glaciation in counties Meath, Westmeath and Cavan

ABSTRACT Lowther and Griffith islands, in the centre of Parry Channel, were overrun by the Laurentide Ice Sheet early in the last glaciation. Northeastward Laurentide ice flow persisted across at least Lowther Island until early Holocene déglaciation. Well constrained postglacial emergence curves for the islands confirm a southward dip of raised shorelines, contrary to the dip expected from the ice load configuration. This and previously reported incongruities may indicate regionally extensive tectonic complications of postglacial rebound aligned with major structural elements in the central Canadian Arctic Islands.

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Inferences on glacial flow from till clast dispersal, Waterford area, New Brunswick

Géographie physique et Quaternaire ◽

10.7202/004773ar ◽

2002 ◽

Vol 51 (1) ◽

pp. 29-39 ◽

Cited By ~ 8

Author(s):

B. E. Broster ◽

M. D. Munn ◽

A. G. Pronk

Keyword(s):

New Brunswick ◽

Secondary Source ◽

Dispersal Patterns ◽

Glacial Erosion ◽

Central Plateau ◽

Ice Flow ◽

Last Glaciation ◽

Flow Directions ◽

Surrounding Areas ◽

Basal Till

Abstract Dispersal patterns for till clasts from the Waterford area, New Brunswick, are compared to source outcrops and used to confirm dominant ice-flow directions in a region reported to show multiple and conflicting striae directions. The results demonstrate that the last glaciation produced elongated south and eastward trending dispersal patterns, indicative of the dominant ice-flow directions. Clasts have been derived locally. Train lengths generally vary from 4 km to about 10 km for material in basal till, but can achieve distances up to 26 km because of transport in englacial positions. Felsic and intermediate metavolcanic and intrusive clasts occur in till at locations north of outcropping plutons on the Central Plateau. The till overlies part of the Carboniferous Basin and has been derived in part, from underlying conglomerate bedrock. Since these conglomerate units contain fragments from the surrounding areas including the Central Plateau, they provided a secondary source for some lithologies during glaciation. Glacial erosion of underlying conglomerate units may account for occurrences of distinctive till clasts found at other areas of the New Brunswick lowlands, previously thought to imply northward glacial transport.

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Glazialtektonik im Weichselglazial Schleswig Holsteins und ihre Beziehungen zur Morphologie

Bulletin of the Geological Society of Denmark ◽

10.37570/bgsd-1985-34-04 ◽

1985 ◽

Vol 34 ◽

pp. 33-45

Author(s):

W. Prange

Keyword(s):

Tectonic Structures ◽

Ice Flow ◽

Last Glacial ◽

Last Glaciation ◽

The Relationship ◽

Glacial Advance ◽

The Last Glacial

Detailed glaciotectonic studies have been conducted in the Weichselian glaciated area of Schleswig-Holstein in order to obtain a better understanding about the stratigraphy, the morphogenetic development and thus about the Pleistocene events towards the end of the last glaciation. In general, an upper till discordantly overlies a lower till, which is partly cove'red with meltwater deposits. The thin upper till cover is probably derived from the last ice readvance in the Oldest Tundra Time, the so-called »Fehmam-advance•, because artifacts found under this till belong to the Younger Hamburg Culture. Various ice tectonic structures such as block-faulted zones, overthrusted folds and folds were observed in these overridden strata. The different directions of the last glacial advance have been determined. The relationship between them and the interpretation of the morphology after Gripp (1952, 1954) is correlated and illustrated with field examples: It is possible to determine the direction of the ice flow from the morphology only in regions with strong and definite topography. However, in the gentler rolling regions with weaker and indistinct morphology the overridden strata may either be disturbed or undisturbed without perceptible changes in their palaeorelief. Therefore in these regions, the present day morphology is not the result of the last ice advance alone, but is due to a combination of the penultimate ice advance, the following meltwater deposition, the last ice readvance and subsequent melting of dead ice.

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Late Wisconsin ice-flow history in the Buffalo Head Hills kimberlite field, north-central Alberta

Canadian Journal of Earth Sciences ◽

10.1139/cjes-2014-0109 ◽

2015 ◽

Vol 52 (1) ◽

pp. 51-67 ◽

Cited By ~ 7

Author(s):

Roger C. Paulen ◽

M. Beth McClenaghan

Keyword(s):

Marine Sediments ◽

Maximum Phase ◽

Ice Flow ◽

North Central ◽

Peace River ◽

Last Glaciation ◽

Proglacial Lakes ◽

Northern Alberta ◽

Kimberlite Field ◽

Bedrock Outcrop

Ice flow of the last glaciation in the Buffalo Head Hills kimberlite field of northern Alberta is reconstructed from landform interpretations and clast orientations for the purpose of aiding kimberlite exploration in the region. The paucity of bedrock outcrop and the absence of preserved striae and other erosional ice-flow indicators on the soft Cretaceous marine sediments inhibit detailed interpretations on glacial flow chronology. Poorly developed bedrock drumlins on the Buffalo Head Hills and erosional ice-flow indicators preserved on the kimberlite outcrops indicate southwestward ice flow during the maximum extent of ice during the last glaciation. During the deglaciation of northern Alberta, later phases of ice flow were controlled by lobes of surging ice, which surged into proglacial lakes. West of the Buffalo Head Hills, the maximum phase of southwest flow was followed by southeastward ice movement of the Peace River ice lobe. Similarly, east of the Buffalo Head Hills, the maximum phase of ice flow was superceded by a south-southwest ice advance of the Wasbasca ice lobe.

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