Hudson Bay river sediments and regional glaciation: I. Iron and carbonate dispersal trains southwest of Hudson and James Bays

1983 ◽  
Vol 20 (2) ◽  
pp. 290-304 ◽  
Author(s):  
J. D. Adshead
Keyword(s):  
Iron Content ◽  
River Sediments ◽  
Hudson Bay ◽  
Sand Fraction ◽  
Ice Flow ◽  
Iron Enrichment ◽  
Dominant Pattern ◽  
Carbonate Composition ◽  
North And South

Sands deposited from rivers draining the southwesterly trending watershed of the Cape Henrietta Maria area are enriched in calcite and are characterized by higher calcite/dolomite ratios than the sands from rivers north and south of the cape. This pattern suggests that a train of drift with distinctive carbonate composition extends southwest of Cape Henrietta Maria, indicating a dominant pattern of southwesterly ice flow in this region.Iron contents are highest for sands from rivers on Cape Henrietta Maria, suggesting iron enrichment in the sand fraction of tills in the cape area, and the existence of a broad dispersal train extending southwest of the cape. The dispersal train inferred from the calcite/dolomite ratios overprints part, but not all, of the dispersal train inferred from the iron content.

Hudson Bay river sediments and regional glaciation: III. Implications of mineralogical studies for Wisconsinan and earlier ice-flow patterns

1983 ◽  
Vol 20 (2) ◽  
pp. 313-321 ◽  
Author(s):  
J. D. Adshead
Keyword(s):  
River Sediments ◽  
Flow Patterns ◽  
Hudson Bay ◽  
James Bay ◽  
Dispersal Patterns ◽  
Regional Patterns ◽  
Ice Flow ◽  
Fluvial Sediment ◽  
Sediment Data ◽  
James Bay Lowlands

Mineralogical studies of river sediments from the Hudson Bay and James Bay Lowlands suggest that the glacial erosion of pre-Devonian Paleozoic carbonate rocks played an important role in the production of calcite-enriched debris in the Cape Henrietta Maria watershed. Ice flowing southwesterly across Devonian basins in western Hudson Bay and the James Bay Lowlands would largely bypass the intervening cape area.Enrichment of iron in river sands of the cape watershed is attributed to Proterozoic ferruginous sources now largely submerged under the waters of eastern Hudson Bay. Distributional patterns of carbonates and iron indicate that the dominant flow of ice from eastern Hudson Bay was southwesterly toward Cape Henrietta Maria, without major flow from the area of Proterozoic bedrock into the Nelson River watershed. In the cape area, iron enrichment due to Proterozoic sources significantly overshadows possible contributions from siderite-bearing Devonian bedrock.The fluvial sediment data are consistent with a multiple dome model of glaciation with ice mass centres located east and west of Hudson Bay. However, quartz/(total carbonate) ratios indicate that, if independent ice masses existed in this configuration, the dominant position of their contact should be placed north of the Churchill–Nelson watershed boundary. Indications of K-feldspar enrichment in Churchill sands are not evident in cape localities where ice flow was southwesterly.Rivers sands are composite channel samples of a drift cover that includes several pre-Wisconsinan tills as well as Wisconsinan deposits. Well defined regional patterns of composite (fluvial) sediment composition suggest a consistency in dominant regional ice movements through time. Similarities between regional drift dispersal limits based on these composite sediments and on pebble dispersal patterns for Wisconsinan tills further indicate that dominant ice-flow patterns in central Canada were probably similar for Wisconsinan and earlier glaciations.

Hudson Bay river sediments and regional glaciation: II. Comparison of carbonate mineralogy of size fractions for ice movement inference

1983 ◽  
Vol 20 (2) ◽  
pp. 305-312 ◽  
Author(s):  
J. D. Adshead
Keyword(s):  
River Sediments ◽  
Regional Distribution ◽  
Hudson Bay ◽  
Primary Control ◽  
Coarse Silt ◽  
Fine Silt ◽  
Ice Flow ◽  
Size Fractions ◽  
Size Grade ◽  
Original Crystal

Comparison of the carbonate mineralogy of sand, coarse silt, fine silt, and coarse clay fractions of river sediments from the Hudson Bay region demonstrates that dolomite is more abundant than calcite in the coarse silts but is less abundant than calcite in other size fractions. In coarse silts, dolomite commonly occurs as single crystals in the shape of well defined rhombs, whereas calcite is present as equant to subequant grains (few rhomb-shaped crystals). Dolomite grains appear to have greater resistance to abrasion than calcite grains after particles have been reduced to sizes lying in the coarse silt range. Although differing physical properties may play a role, it appears likely that the primary control on the particle size distributions of the carbonate minerals is their original crystal size in the source bedrock.The calcite/dolomite ratio for dolomite-enriched coarse silt parallels the regional distribution observed for sand, fine silt, and coarse clay, with highest values occurring in the Cape Henrietta Maria area. Carbonate mineral ratios for silt and clay fractions corroborate the results obtained for sands and provide further evidence for the existence of a carbonate dispersal train extending southwest of the cape. These results further demonstrate that fluvial carbonates can be useful indicators of regional drift dispersal and ice-flow patterns.The widespread use of silt or combined silt and clay fractions for calcite and dolomite determinations in drift provenance studies is not upheld by the results of this investigation. Coarse silts, which have been enriched in dolomite due to abrasion processes, provide a substantially distorted interpretation of source bedrock composition. Use of the sand-size grade is advocated. Sands, unlike coarse silts, reflect the major occurrence of limestones and minor dolostones in Paleozoic basins of the region.

scholarly journals Objective Reconstructions of the Late Wisconsinan Laurentide Ice Sheet and the Significance of Deformable Beds

2007 ◽  
Vol 39 (3) ◽  
pp. 229-238 ◽  
Author(s):  
D. A. Fisher ◽  
N. Reeh ◽  
K. Langley
Keyword(s):  
Yield Stress ◽  
Flow Direction ◽  
Three Dimensional ◽  
Ice Sheet ◽  
Laurentide Ice Sheet ◽  
Hudson Bay ◽  
Ice Streams ◽  
Ice Flow ◽  
Surface Slopes ◽  
Late Wisconsinan

ABSTRACT A three dimensional steady state plastic ice model; the present surface topography (on a 50 km grid); a recent concensus of the Late Wisconsinan maximum margin (PREST, 1984); and a simple map of ice yield stress are used to model the Laurentide Ice Sheet. A multi-domed, asymmetric reconstruction is computed without prior assumptions about flow lines. The effects of possible deforming beds are modelled by using the very low yield stress values suggested by MATHEWS (1974). Because of low yield stress (deforming beds) the model generates thin ice on the Prairies, Great Lakes area and, in one case, over Hudson Bay. Introduction of low yield stress (deformabie) regions also produces low surface slopes and abrupt ice flow direction changes. In certain circumstances large ice streams are generated along the boundaries between normal yield stress (non-deformable beds) and low yield stress ice (deformabie beds). Computer models are discussed in reference to the geologically-based reconstructions of SHILTS (1980) and DYKE ef al. (1982).

A reconstruction of glacial events in southeastern New Brunswick

1991 ◽  
Vol 28 (10) ◽  
pp. 1594-1612 ◽  
Author(s):  
Marc Foisy ◽  
Gilbert Prichonnet
Keyword(s):  
New Brunswick ◽  
Ice Flow ◽  
Ice Cap ◽  
The North ◽  
Lithostratigraphic Units ◽  
Glaciofluvial Deposits ◽  
Southern Border ◽  
Late Wisconsinan ◽  
Radial Outflow ◽  
North And South

Sedimentological and petrographical data obtained from five sections located north and south of the Caledonian Highlands in southeastern New Brunswick demonstrate the existence of three main till units and one glaciofluvial unit, which have been grouped in four distinct lithostratigraphic units. The lower till was deposited by a glacier that overrode the Caledonian Highlands from northwest to southeast and advanced as far as Nova Scotia during Middle(?) to Late Wisconsinan times. The overlying middle till from the north provides evidence that ice continued to advance across the Highlands from northwest toward southeast and then was partially overwhelmed by another glacier that was advancing southwest along the southern border of the Highlands: this glacier deposited a coeval middle till. During Late Wisconsinan deglaciation, ice separated into two masses: a residual ice cap with radial outflow from the Highlands; and a lobe in the Chignecto Bay, retreating toward the northeast. The existence of a plateau ice cap is demonstrated by the presence of till and glaciofluvial deposits in the upper part of all surveyed sections, and is supported by the sequence of ice flow patterns recorded by striae and the centrifugal distribution of meltwater flow indicators. The weak development of soils, the fresh appearance of till and morainic landforms, and the lack of periglacial features throughout the area, especially on the Highlands, all favour the interpretation that the Caledonian Highlands were not a nunatak during the glacial maximum of the Late Wisconsinan Substage.

Southeastward ice flow in central Quebec and its paleogeographic significance

1985 ◽  
Vol 22 (10) ◽  
pp. 1536-1541 ◽  
Author(s):  
Michel A. Bouchard ◽  
Ghismond Martineau
Keyword(s):  
Hudson Bay ◽  
East Side ◽  
James Bay ◽  
Rock Outcrops ◽  
Ice Flow ◽  
West Central

Directional glacial erosional marks located systematically on the southwest side of rock outcrops in the Chibougamau and Lac Mistassini areas in west-central Quebec indicate unequivocally a sustained regional event of southeast ice flow prior to the last or regional southwest flow from New Quebec. Striations from the former ice flow are consistently oriented at around 120° azimuth and are observed, albeit at scattered occurrences, within an area covering thousands of square kilometres. Although the age of the southeast ice flow event cannot be determined, it is considered more likely to be of Wisconsinan age on the basis of the well preserved state of its features and the lack of deep weathering on surfaces where these are observed. It is suggested that the early ice flow event might have been fed by a local outflow centre on the east side of James Bay, perhaps extending as a ridge east of Hudson Bay.

A woolly mammoth (Proboscidea, Mammuthus primigenius) molar from the Hudson Bay Lowland of Manitoba

1988 ◽  
Vol 25 (6) ◽  
pp. 933-938 ◽  
Author(s):  
Erik Nielsen ◽  
C. S. Churcher ◽  
G. E. Lammers
Keyword(s):  
Depositional Environment ◽  
River Sediments ◽  
Hudson Bay ◽  
Tree Line ◽  
Mammuthus Primigenius ◽  
Early Form ◽  
Enamel Thickness ◽  
Hudson Bay Lowland ◽  
Woolly Mammoth

The first fossil mammal from the Hudson Bay Lowland of Manitoba, a molar from the woolly or Siberian mammoth, Mammuthus primigenius, is described from near Bird. A lophar index of 9.0 and an enamel thickness of 1.5–2.3 mm allow the tooth to be assigned to an early form of the species. Although in situ provenance of the molar is unknown, it is likely that the molar derives from Early Wisconsinan or Sangamon sediments that outcrop in the area. A boreal steppe or steppe–tundra environment is indicated by the presence of woolly mammoth, supporting a depositional environment north of the then tree line previously established for the Nelson River sediments.

scholarly journals Laurentide Ice-Flow Patterns: A Historical Review, and Implications of the Dispersal of Belcher Islands Erratics

2007 ◽  
Vol 44 (2) ◽  
pp. 113-136 ◽  
Author(s):  
Victor K. Prest
Keyword(s):  
Ice Sheet ◽  
Historical Review ◽  
Flow Patterns ◽  
The Arctic ◽  
Laurentide Ice Sheet ◽  
Complex Nature ◽  
Hudson Bay ◽  
Ice Flow ◽  
Flow Models ◽  
The North

ABSTRACTThis paper deals with the evolution of ideas concerning the configuration of flow patterns of the great inland ice sheets east of the Cordillera. The interpretations of overall extent of Laurentide ice have changed little in a century (except in the Arctic) but the manner of growth, centres of outflow, and ice-flow patterns, remain somewhat controversial. Present geological data however, clearly favour the notion of multiple centres of ice flow. The first map of the extent of the North American ice cover was published in 1881. A multi-domed concept of the ice sheet was illustrated in an 1894 sketch-map of radial flow from dispersal areas east and west of Hudson Bay. The first large format glacial map of North America was published in 1913. The binary concept of the ice sheet was in vogue until 1943 when a single centre in Hudson Bay was proposed, based on the westward growth of ice from Labrador/Québec. This Hudson dome concept persisted but was not illustrated until 1977. By this time it was evident from dispersal studies that the single dome concept was not viable. Dispersal studies clearly indicate long-continued westward ice flow from Québec into and across southern Hudson Bay, as well as eastward flow from Keewatin into the northern part of the bay. Computer-type modelling of the Laurentide ice sheet(s) further indicates their complex nature. The distribution of two indicator erratics from the Proterozoicage Belcher Island Fold Belt Group help constrain ice flow models. These erratics have been dispersed widely to the west, southwest and south by the Labrador Sector of more than one Laurentide ice sheet. They are abundant across the Paleozoic terrain of the Hudson-James Bay lowland, but decrease in abundance across the adjoining Archean upland. Similar erratics are common in northern Manitoba in the zone of confluence between Labrador and Keewatin Sector ice. Scattered occurences across the Prairies occur within the realm of south-flowing Keewatin ice. As these erratics are not known, and presumably not present, in Keewatin, they indicate redirection and deposition by Keewatin ice following one or more older advances of Labrador ice. The distribution of indicator erratics thus test our concepts of ice sheet growth.

scholarly journals PISM-LakeCC: Implementing an adaptive proglacial lake boundary into an ice sheet model

2020 ◽  
Author(s):  
Sebastian Hinck ◽  
Evan J. Gowan ◽  
Xu Zhang ◽  
Gerrit Lohmann
Keyword(s):  
Boundary Conditions ◽  
Ice Sheet ◽  
Laurentide Ice Sheet ◽  
Hudson Bay ◽  
Ice Streams ◽  
Ice Flow ◽  
Glacial Retreat ◽  
Proglacial Lakes ◽  
Lake Model ◽  
Ice Sheet Dynamics

Abstract. Geological records show that vast proglacial lakes existed along the land terminating margins of palaeo ice sheets in Europe and North America. Proglacial lakes impact ice sheet dynamics by imposing marine-like boundary conditions at the ice margin. These lacustrine boundary conditions include changes in the ice sheet’s geometry, stress balance and frontal ablation and therefore affect the entire ice sheet’s mass balance. This interaction, however, has not been rigorously implemented in ice sheet models. In this study, the implementation of an adaptive lake boundary into the Parallel Ice Sheet Model (PISM) is described and applied to the glacial retreat of the Laurentide Ice Sheet (LIS). The results show that the presence of proglacial lakes locally enhances the ice flow. Along the continental ice margin, ice streams and ice lobes can be observed. Lacustrine terminating ice streams cause immense thinning of the ice sheet’s interior and thus play a significant role in the demise of the LIS. Due to the presence of lakes, a process similar to the marine ice sheet instability causes the collapse of the ice saddle over Hudson Bay, which blocked drainage via the Hudson Strait. In control experiments without a lake model, Hudson Bay is still glaciated at the end of the simulation. Future studies should target the development of parametrizations that better describe the glacial-lacustrine interactions.

scholarly journals Permo-Carboniferous Glaciogenic Al Khlata Formation, Oman: A New Hypothesis for Origin of its Glaciation

GeoArabia ◽  
1996 ◽  
Vol 1 (3) ◽  
pp. 389-404
Author(s):  
Juma D. Al-Belushi ◽  
Kenneth W. Glennie ◽  
Brian P.J. Williams
Keyword(s):  
Arabian Sea ◽  
Arabian Peninsula ◽  
Flow Direction ◽  
Fold Axis ◽  
Early Permian ◽  
Ice Flow ◽  
Crustal Uplift ◽  
A Site ◽  
North And South ◽  
New Hypothesis

ABSTRACT Al Khlata Formation is an oil-bearing reservoir in Oman. Its origin during the Late Palaeozoic Gondwana glaciation in the southern part of the Arabian Peninsula is demonstrated by the glaciogenic deposits of the formation in Oman. Outcrops of the Al Khlata Formation occur in a belt parallel to the Huqf fold axis, the best outcrops being found in the two wadis Al Khlata North and South. In the southern wadi, glacial deposits rest directly on dolomites of the Precambrian Khufai Formation showing northeast-southwest trending glacial striations. Earlier workers proposed that the direction of ice flow was from the southwest to northeast. This is not accepted in this paper, where evidence is presented to support an ice-flow direction from northeast to southwest. Later fluvial flow towards the northeast possibly resulted from the collapse of the continental margin towards the new Proto-Arabian Sea and its subsequent subsidence. We propose that the Early Permian glaciation in Oman resulted from crustal uplift just prior to the calving of a microcontinent along the northeast Arabia margin of Gondwana and the creation of Neo-Tethys. It is suggested that the triple-junction area where the Neo-Tethys and the Proto-Arabian Sea were later to meet, was a site of sufficient thermal uplift to become a center of mountain glaciation.

Ice-flow patterns and glacial transport in the eastern Hudson Bay region: implications for the late Quaternary dynamics of the Laurentide Ice Sheet

1995 ◽  
Vol 32 (12) ◽  
pp. 2057-2070 ◽  
Author(s):  
Michel Parent ◽  
Serge J. Paradis ◽  
Éric Boisvert
Keyword(s):  
Compositional Data ◽  
Late Quaternary ◽  
Regional Distribution ◽  
Ice Sheet ◽  
Glacial Maximum ◽  
Laurentide Ice Sheet ◽  
Hudson Bay ◽  
Ice Flow ◽  
Flow Phase ◽  
Late Wisconsinan

Recent field surveys in the eastern Hudson Bay region have led to the discovery of regional ice-flow sequences that require a significant reassessment of the late Quaternary dynamics of the Laurentide Ice Sheet. Two regional ice-flow phases can be recognized from till compositional data and from crosscutting relationships observed on striated bedrock surfaces: the oldest is directed toward the northwest and north-northwest, while the youngest is directed toward the west and includes a late-glacial deflection toward the southwest. The wide regional distribution of striae formed during the early northwestward glacial movement together with the recognition of palimpsest glacial dispersal trains associated with this phase suggest that it was a long-lived, time-transgressive regional event. The ensuing glacial movement is a regionally dominant westward ice-flow phase during which several large glacial dispersal trains were formed downglacier from distinctive bedrock sources. The largest of these trains extends westward over a distance of 120 km from Lac à l'Eau Claire to Hudson Bay. Regional glacial transport data as well as glacial and deglacial landforms indicate that this was a long-lived glacial phase, likely lasting throughout the Late Wisconsinan glacial maximum and until déglaciation about 8000 BP. The erosional and depositional record of the northwestward ice-flow event is quite comparable to that of the ensuing glacial phase, and it is thus thought to represent the Early Wisconsinan glacial maximum. In view of the large regional extent of the northwestward ice-flow phase, it must postdate the early buildup of the ice sheet. Along the southeastern Hudson Bay coast, the Late Wisconsinan westward glacial movement was followed by a southwestward deflection that was likely caused by glacial streaming prior to 8000 BP in James Bay, in response to calving and surging into Glacial Lake Ojibway.

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