Evidence for Early Pleistocene glaciation from borecore stratigraphy in north-central Alberta, Canada

2017 ◽  
Vol 54 (4) ◽  
pp. 445-460 ◽  
Author(s):  
Laurence D. Andriashek ◽  
René W. Barendregt
Keyword(s):  
Late Pleistocene ◽  
Rocky Mountains ◽  
New Record ◽  
Early Pleistocene ◽  
Laurentide Ice Sheet ◽  
Pleistocene Glaciation ◽  
North Central ◽  
Lake Formation ◽  
Colorado Group ◽  
Late Wisconsinan

Pleistocene sediments collected in north-central Alberta, Canada, were subsampled and studied for paleomagnetic remanence characteristics. A magnetostratigraphy has been established for sediments previously assumed to represent multiple continental (Laurentide) glaciations but for which no geochronology was available. Based on the Quaternary record elsewhere in Alberta and Saskatchewan, it was thought that some of these sediments were deposited during pre-late Wisconsinan glaciations. The Quaternary sedimentary successions of north-central Alberta have a thickness up to 300 m within buried valleys and are composed of diamicts interbedded with glaciolacustrine and outwash sediments. Most of the sampled units are not accessible from outcrop, and their sedimentology and stratigraphy is derived from core data only. In 4 of 16 borecores sampled to date, diamict that correlates with the Bronson Lake Formation till is reversely magnetized, indicating an Early Pleistocene age. This formation is underlain by either Empress Formation sediments or Colorado Group shale, and is overlain by one or more normally magnetized glacigenic sedimentary units of the Bonnyville, Marie Creek, and Grand Centre formations, respectively. This new record of Early Pleistocene glaciation in north-central Alberta places the westernmost extent of earliest Laurentide ice at least 300 km farther west than its previously established limit in the Saskatoon and Regina regions of the Canadian Interior Plains, but still to the east of the maximum extent of the Late Wisconsinan (Late Pleistocene) Laurentide Ice Sheet, which extended into the foothills of the Alberta and Montana Rocky Mountains.

Stratigraphy and structure of a Late Wisconsinan salt collapse in the Saskatoon Low, south of Saskatoon, Saskatchewan, Canada: an update

2001 ◽  
Vol 38 (11) ◽  
pp. 1601-1613 ◽  
Author(s):  
E A Christiansen ◽  
E Karl Sauer
Keyword(s):  
Late Pleistocene ◽  
Middle Devonian ◽  
Upper Cretaceous ◽  
Middle Pleistocene ◽  
Second Phase ◽  
The South ◽  
Glacial Erosion ◽  
Lake Formation ◽  
South Saskatchewan River ◽  
Late Wisconsinan

The Saskatoon Low is a collapse structure that formed as a result of dissolution of salt from the Middle Devonian Prairie Evaporite Formation. In this study, the collapse has affected the Upper Cretaceous Lea Park, Judith River, and Bearpaw formations of the Montana Group; the Early and Middle Pleistocene Mennon, Dundurn, and Warman formations of the Sutherland Group; and the Late Pleistocene Floral, Battleford, and Haultain formations of the Saskatoon Group. Locally, the collapse is about 180 m, which is about equal to the thickness of the salt. The first phase of collapse took place after deposition of the Ardkenneth Member of the Bearpaw Formation and before glaciation or during a pre-Illinoian glaciation. The second phase of collapse occurred during the Battleford glaciation (Late Wisconsinan). Prior to deposition of the Battleford Formation, the Saskatoon Low was glacially eroded, removing the Sutherland Group and the Floral Formation. After the glacial erosion, up to 110 m of soft till of the Battleford Formation and up to 77 m of deltaic sand, silt, and clay of the Haultain Formation were deposited in the Saskatoon Low. Lastly, the South Saskatchewan River eroded up to about 40 m into the deltaic sediment and tills before up to about 15 m of Pike Lake Formation was deposited. The Haultain and Pike Lake formations are new stratigraphic units.

COLLAPSE STRUCTURES NEAR SASKATOON, SASKATCHEWAN, CANADA

1967 ◽  
Vol 4 (5) ◽  
pp. 757-767 ◽  
Author(s):  
E. A. Christiansen
Keyword(s):  
Late Pleistocene ◽  
Point Group ◽  
Pleistocene Glaciation ◽  
High Angle ◽  
Bedrock Surface ◽  
Colorado Group ◽  
Collapse Structures

A structural depression herein called the "Saskatoon. Low" is apparent on structural maps drawn on the top of the Lea Park Formation–Upper Colorado Group, on the bedrock surface, and on the uppermost till surface. The structure was probably formed by collapse as a result of the removal of salt from the Elk Point Group. The structure presumably comprises numerous individual fault blocks, which are bounded by high-angle step faults. The structure may have started to form during deposition of the Bearpaw Formation. It was well developed, however, at the time of the advent of Pleistocene glaciation and continued to develop until late Pleistocene time. The final collapse is radiocarbon dated at about 12 000 years ago.

Late Pleistocene depositional systems of Metropolitan Toronto and their engineering and glacial geological significance

1987 ◽  
Vol 24 (5) ◽  
pp. 1009-1021 ◽  
Author(s):  
N. Eyles
Keyword(s):  
Late Pleistocene ◽  
Cross Sections ◽  
Laurentide Ice Sheet ◽  
Drainage Network ◽  
Glacial History ◽  
Late Tertiary ◽  
History Of ◽  
Depositional Systems ◽  
Late Wisconsinan ◽  
Glacial Complex

The municipality of Metropolitan Toronto (area 480 km2, population 2.15 million) is centrally located on the Late Pleistocene sedimentary infill of the Laurentian Channel, a broad bedrock low up to 115 km wide connecting the Huron and Ontario basins. This channel forms part of a relict (late Tertiary?) drainage network (the Laurentian River) modified by Pleistocene glacial erosion and infilled by over 100 m of glacial and interglacial sediments. The subsurface stratigraphy of the channel fill below Metropolitan Toronto has been established from many different data sources and is depicted, in this paper, as a series of cross sections with a total length of nearly 105 km.The subsurface stratigraphy has been divided, provisionally, into five depositional complexes, which have been mapped in the subsurface along several transects. These are (1) a glacial complex of Illinoian (?) age, (2) a lacustrine complex of Sangamon Interglacial and earliest Wisconsinan sediments (120 000 – 75 000 BP?), (3) a glaciolacustrine – lacustrine complex spanning the Early and Mid-Wisconsinan (75 000 – 30 000 BP?), (4) a Late Wisconsinan (> 30 000 BP) glacial complex, and (5) a postglacial lacustrine complex (ca. 12 000 BP).The data presented in this paper are significant for applied geological investigations in the heavily urbanized Toronto area and provide new insights into the glacial history of the Ontario Basin, in particular the regional extent of the Laurentide Ice Sheet margin prior to the Late Wisconsinan.

scholarly journals New Zealand Glaciations and the Duration of The Pleistocene

1961 ◽  
Vol 3 (29) ◽  
pp. 940-943 ◽  
Author(s):  
Maxwell Gage
Keyword(s):  
New Zealand ◽  
Recent Work ◽  
Late Pleistocene ◽  
Early Pleistocene ◽  
Pleistocene Glaciation ◽  
Shield Volcano ◽  
Geological Evidence ◽  
Pleistocene Period

Abstract Recent work has resulted in recognition of an additional glaciation preceding the Waimaunga Glaciation in the late Pleistocene. This followed the mid-Pleistocene climax of earth movements responsible for most of the present mountainous relief of New Zealand, but only after an interval of time long enough for the construction and subsequent deep dissection of Banks Peninsula shield volcano. It is inferred from this and other geological evidence that the earliest late Pleistocene glaciation was separated from the early Pleistocene Ross Glaciation by several hundred thousand years, and that the Pleistocene Period altogether covers at least one million years.

scholarly journals New Zealand Glaciations and the Duration of The Pleistocene

1961 ◽  
Vol 3 (29) ◽  
pp. 940-943
Author(s):  
Maxwell Gage
Keyword(s):  
New Zealand ◽  
Recent Work ◽  
Late Pleistocene ◽  
Early Pleistocene ◽  
Pleistocene Glaciation ◽  
Shield Volcano ◽  
Geological Evidence ◽  
Pleistocene Period

AbstractRecent work has resulted in recognition of an additional glaciation preceding the Waimaunga Glaciation in the late Pleistocene. This followed the mid-Pleistocene climax of earth movements responsible for most of the present mountainous relief of New Zealand, but only after an interval of time long enough for the construction and subsequent deep dissection of Banks Peninsula shield volcano. It is inferred from this and other geological evidence that the earliest late Pleistocene glaciation was separated from the early Pleistocene Ross Glaciation by several hundred thousand years, and that the Pleistocene Period altogether covers at least one million years.

Late Wisconsinan Cordilleran and Laurentide glaciation of the Peace River Valley east of the Rocky Mountains, British Columbia

2018 ◽  
Vol 55 (12) ◽  
pp. 1324-1338 ◽  
Author(s):  
Gregory M.D. Hartman ◽  
John J. Clague ◽  
René W. Barendregt ◽  
Alberto V. Reyes
Keyword(s):  
Rocky Mountains ◽  
Ice Sheet ◽  
River Valley ◽  
Laurentide Ice Sheet ◽  
Eastern Front ◽  
Peace River ◽  
Stratigraphic Framework ◽  
Mountain Front ◽  
Late Wisconsinan ◽  
Cordilleran Ice Sheet

In the past, researchers have disagreed over the maximum extent of the Cordilleran Ice Sheet in the Peace River valley during the Late Wisconsinan. Some workers argued that Cordilleran ice reached beyond the Rocky Mountains and briefly coalesced with the Laurentide Ice Sheet on the westernmost Interior Plains. In contrast, others asserted that Cordilleran ice did not reach beyond the eastern front of the Rocky Mountains. Stratigraphic interpretation of three sections within a Middle Wisconsinan paleovalley and re-examination of a previously published regional stratigraphic framework show that western-sourced ice (likely the Cordilleran Ice Sheet) extended east of the mountain front during the Late Wisconsinan, prior to the incursion of the Laurentide Ice Sheet into the area. This conclusion has implications for Cordilleran Ice Sheet reconstruction and modelling, and provides insight into the interactions between the Cordilleran and Laurentide ice sheets during the last glaciation.

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