Pleistocene stratigraphy of the Saskatoon area, Saskatchewan, Canada: an update

1992 ◽  
Vol 29 (8) ◽  
pp. 1767-1778 ◽  
Author(s):  
E. A. Christiansen
Keyword(s):  
Ice Sheet ◽  
Carbonate Content ◽  
Stratigraphic Position

Pleistocene deposits in the Saskatoon area are divided into the Sutherland and Saskatoon groups. The Sutherland Group is divided into the Mennon, Dundurn, and Warman formations, and the Saskatoon Group is divided into the Floral and Battleford formations. The Floral Formation is subdivided into the lower till, the Riddell Member, and the upper till. Each formation is composed of a sequence of deposits, including basal proglacial sediment, till, upper proglacial sediment, and nonglacial sediment. Each formation is defined primarily on the basis of carbonate content and stratigraphic position of its till, and commonly it is bounded by weathered zones and (or) nonglacial sediments. The Sutherland Group is pre-Illinoian in age, and the lower till of the Floral Formation is Illinoian in age. The Riddell Member, between the lower and upper tills of the Floral Formation, is late Rancholabrean, probably Sangamon, in age. Radiocarbon ages of sediments lying between the upper till of the Floral Formation (Early Wisconsin) and the Battleford Formation (Late Wisconsin) range from more than 38 000 to 18 000 BP. The dissipating ice sheet margin stood in the vicinity of Saskatoon about 12 000 BP.

Wascana Creek Ash (Middle Pleistocene) in southern Saskatchewan: characterization, source, fission track age, palaeomagnetism and stratigraphic significance

1977 ◽  
Vol 14 (3) ◽  
pp. 357-374 ◽  
Author(s):  
J. A. Westgate ◽  
E. A. Christiansen ◽  
J. D. Boellstorff
Keyword(s):  
Mineral Assemblage ◽  
National Park ◽  
Fission Track ◽  
Volcanic Glass ◽  
The United States ◽  
Middle Pleistocene ◽  
Carbonate Content ◽  
Stratigraphic Position

Wascana Creek Ash, located close to Regina in Saskatchewan, is correlated with Pearlette ash, type O (classification of Izett et al. 1972) on the basis of its mineral assemblage, shard habit, composition of glass, titanomagnetite and chevkinite. Directions of magnetization and normal polarization of clay immediately below Wascana Creek ash further support this correlation, which is essentially confirmed by the fission track age of volcanic glass and zircon that show Wascana Creek Ash to be 0.6–0.7 Ma.Pearlette ash, type O, is derived from vents in Yellowstone National Park in Wyoming and Idaho, situated about 800 km southwest of Wascana Creek in Saskatchewan. Its air-fall tephra is widely distributed in the form of isolated lentils over the midcontinent region of the United States where stratigraphic relationships suggest a late Kansan, Yarmouth, or early Illinioan age.Wascana Creek Ash and its host clay occupy an intertill position; they rest directly on sandy till, interpreted as part of the Floral Formation, and are covered by till of the Battleford Formation. Thus, the Floral Formation in Saskatchewan may well be as old as the Kansan—that is, decidedly older than most current estimates, which favour an early Wisconsin age.The horizontal disposition and palaeomagnetic characteristics of the host clay, uniformity of carbonate content of the underlying till, and absence of local glaciotectonic features strongly suggest that the tephra and clay are in situ and not glacial erratics that have been transported as blocks from an older deposit. Furthermore, extensive reworking of the tephra from an older horizon is considered unlikely in view of minor detrital contamination, fresh glass, and conspicuous crop of glass-sheathed heavies. However, the stratigraphic position of Wascana Creek Ash should not be considered as firmly established for these observations of necessity pertain to just one locality; further occurrences must be found and studied before its stratigraphic position can be confidently defined.

scholarly journals Reflection of Scandinavian Ice Sheet Fluctuations in Norwegian Sea Sediments during the Past 150,000 Years

1995 ◽  
Vol 43 (2) ◽  
pp. 185-197 ◽  
Author(s):  
Karl-Heinz Baumann ◽  
Klas S. Lackschewitz ◽  
Jan Mangerud ◽  
Robert F. Spielhagen ◽  
Thomas C.W. Wolf-welling ◽  
...  
Keyword(s):  
Early Stage ◽  
Accumulation Rate ◽  
Ice Sheet ◽  
Carbonate Content ◽  
Calcareous Nannofossils ◽  
Norwegian Sea ◽  
The Past ◽  
Glacier Fluctuations ◽  
Late Weichselian ◽  
Glacial Oscillations

AbstractThe record of glacier fluctuations in western Scandinavia, as reconstructed from continental data, has been correlated with records of ice-rafted detritus (IRD) from well-dated sediment cores from the Norwegian Sea covering the past 150,000 yr B.P. The input of IRD into the ocean is used as a proxy for ice sheet advances onto the shelf and, thus, for the calibration of a glaciation curve. The marine results generally support land-based reconstructions of glacier fluctuations and improve the time-control on glacial advances. The Saalian ice sheet decayed very rapidly approximately 125,000 yr B.P. In the Early Weichselian, a minor but significant IRD maximum indicates the presence of icebergs in isotope substage 5b (especially between 95,000 and 83,000 yr B.P.). Reduced amounts of calcareous nannofossils indicate that surface waters were influenced by meltwater discharges during isotope substages 5d and 5b. An extensive build-up of inland ice began again during isotope stage 4, but maximum glaciation was reached only in early stage 3 (58,000-53,000 yr B.P.). Marine sediments have minimum carbonate content, indicating strong dilution by lithogenic ice-rafted material. Generally, the IRD accumulation rate was considerably higher in stages 4-2 than in stage 5. A marked peak in IRD accumulation rates from 47,000 to 43,000 yr B.P. correlates well with a second Middle Weichselian ice sheet advance dated by the Laschamp/Olby paleomagnetic event. Minimum ice extent during the Ålesund interstade (38,500-32,500 yr B.P.) and several glacial oscillations during the Late Weichselian are also seen in the IRD record. Of several late Weichselian glacial oscillations on the shelf, at least four correspond to the North Atlantic Heinrich events. Ice sheet behavior was either coupled or linked by external forcing during these events, whereas internal ice sheet mechanisms may account for the noncoherent fluctuations.

scholarly journals Analysis of the Merden Lake Esker, Stearns County, Minnesota: A New Interpretation

2004 ◽  
Vol 3 (2) ◽  
Author(s):  
Aaron Hirsch ◽  
Larry Davis
Keyword(s):  
Grain Size ◽  
Ice Sheet ◽  
Laurentide Ice Sheet ◽  
Carbonate Content ◽  
Sieve Analysis ◽  
Sedimentary Structures ◽  
South Central ◽  
Gravel Pit ◽  
Superior Lobe ◽  
New Interpretation

A gravel pit in south central Stearns County, Minnesota exposes sand and gravel of the Merden Lake esker which is thought to have been deposited by a subglacial stream associated with the Wisconsinan-aged Superior Lobe of the Laurentide ice sheet. An analysis of these sediments was conducted from samples collected through a vertical trench on an east-facing exposure of the gravel pit. A total of 12 distinct stratigraphic horizons were recognized. Each horizon was described in terms of overall color, grain size, and lithology, carbonate content, and sedimentary structures. A total of 436 clasts (>3 cm) were collected for lithology studies. Trench samples were collected across each horizon for grain size sieve analysis. Clasts were dominated by basalt (37.6%), granite (28.2%), gabbro (14.5%), quartzite (6.2%), diorite (3.5%), mica schist (3%), and andesite (1%). Minor components consisted of pisolitic claystone, shale, sandstone, limestone, dolostone, ironstone, bauxite, quartz, agate, and amethyst. The sedimentology provides an overall color of yellowish-orange to brown. Many of the large clasts (>5 cm) contained a rind of calcareous-cemented course sand. Several large (18-35 cm) armored clay balls were collected from the basal horizon. Grain size ranged from boulders (up to 37 cm in diameter) to clays. Average cobble size was 10.48 cm. The dominant grain size through the trench was 1-2 mm. Sedimentary structures included graded beds, minor cross bedding, and imbrication. Superior Lobe lithologies are dominated by red volcanics and sedimentary rocks from the Middle Proterozoic Keeweenawan Superior Group and have an overall brown to reddish-gray appearance. Rainy (Wadena) Lobe lithologies are dominated by Precambrian igneous and metamorphic rocks from southwest Ontario and northwest Minnesota and have an overall yellowish to yellow-brown appearance. Sedimentological analysis of the Merden Lake esker indicates its characteristics are more consistent with subglacial stream deposition within the Pierz Sublobe of the Rainy Lobe of the Laurentide ice sheet.

Glacier Peak Tephra in the North Cascade Range, Washington: Stratigraphy, Distribution, and Relationship to Late-Glacial Events

1978 ◽  
Vol 10 (1) ◽  
pp. 30-41 ◽  
Author(s):  
Stephen C. Porter
Keyword(s):  
Far East ◽  
Ice Sheet ◽  
Late Glacial ◽  
Cascade Range ◽  
Time Layer ◽  
Terminal Moraine ◽  
The North ◽  
Stratigraphic Position ◽  
Cordilleran Ice Sheet ◽  
Glacial Time

Pumiceous tephra, resulting from multiple eruptions of Glacier Peak volcano in late-glacial time, mantles much of the landscape in the eastern North Cascade Range and extends eastward beyond the Columbia River as a thinner discontinuous deposit. Within about 25 km of the source, the tephra is divisible into as many as nine layers, distinguishable in the field on the basis of color, grain size, thickness, and stratigraphic position. Three principal layers, designated G (oldest), M, and B, are separated from one another by thinner, finer layers. Layer G has been found as far east as Montana and southern Alberta, whereas layer B has been identified as far as western Wyoming. By contrast, layer M trends nearly south, paralleling the crest of the Cascade Range. Available 14C dates indicate that the tephra complex was probably deposited between about 12,750 and 11,250 years ago. Glacier Peak tephra overlies moraines and associated outwash east of the Cascade Crest that were deposited about 14,000 years ago. Unreworked tephra occurs within several kilometers of many valley heads implying that major valley glaciers had nearly disappeared by the time of the initial tephra fall. Distribution of tephra indicates that the southern margin of the Cordilleran Ice Sheet had retreated at least 80 km north of its terminal moraine on the Waterville Plateau by the time layer G was deposited. Late-glacial moraines of the Rat Creek advance lie within the fallout area of layer M but lack the tephra on their surface implying that they were built subsequent to the eruption of this unit. Moraines of the Hyak advance at Snoqualmie Pass, which are correlated with the Rat Creek moraines farther north, were constructed prior to 11,000 14C years ago. The late-glacial advance along the Cascade Crest, therefore, apparently culminated between about 12,000 and 11,000 14C years ago and was broadly in phase with the Sumas readvance of the Cordilleran Ice Sheet in the Fraser Lowland which occurred between about 11,800 and 11,400 14C years ago.

scholarly journals Pre-Late Wisconsinan age for part of the glaciolacustrine stratigraphy, lower Peabody valley, northern White Mountains, Gorham, New Hampshire

2002 ◽  
Vol 53 (1) ◽  
pp. 109-116 ◽  
Author(s):  
Brian K. Fowler
Keyword(s):  
New England ◽  
New Hampshire ◽  
Ice Sheet ◽  
River Valley ◽  
White Mountains ◽  
Southern New England ◽  
Stratigraphic Position ◽  
Late Wisconsinan

Abstract Interbedded till and glaciolacustrine deposits in the lower Peabody River Valley near Gorham, New Hampshire suggest multiple glacial advances occurred in the northern White Mountains. Previous workers disagreed on whether these advances were local or regional in nature, but thought they all occurred during the recessional phase of the Late Wisconsinan ice sheet. New stratigraphic and geomorphic reconnaissance, however, shows that a thick and regionally extensive till overlies this stratigraphy and that this till was emplaced by the last full-glacial episode to affect the region, the Late Wisconsinan glaciation. The stratigraphic position of this till makes the age of the underlying till and glaciolacustrine deposits pre-Late Wisconsinan and much older than previously assumed. This change in age assignment for part of the Peabody Valley stratigraphy supports the extension of the Illinoian-Late Wisconsinan "two-till" stratigraphy of central and southern New England into the region north of the White Mountain Highlands.

Age verification of the Lake Gribben forest bed and the Younger Dryas Advance of the Laurentide Ice Sheet

1999 ◽  
Vol 36 (3) ◽  
pp. 383-393 ◽  
Author(s):  
Thomas V Lowell ◽  
Graham J Larson ◽  
John D Hughes ◽  
George H Denton
Keyword(s):  
Lake Superior ◽  
Ice Sheet ◽  
Younger Dryas ◽  
Laurentide Ice Sheet ◽  
Climatic Forcing ◽  
Glacier System ◽  
Stratigraphic Position ◽  
Age Verification ◽  
Younger Dryas Event ◽  
Age Estimates

Analysis of nine wood samples from the Lake Gribben forest bed near Lake Gribben, Michigan, yielded a combined age of 10 025 ± 100 14C years BP, which confirms and refines prior age estimates for the bed. The stratigraphic position of these samples below a prograding ice-contact fan indicates the time that a glacial margin reached the southern edge of the Lake Superior basin. Geomorphic tracing and correlation of associated deposits indicate that a contemporaneous margin extended almost 1000 km from Duluth, Minnesota, across the Lake Superior basin to North Bay, Ontario. Along the southern shore of Lake Superior ice-margin expansion began during and ended at the close of the Younger Dryas. A surging glacier system would not produce a nearly linear moraine system across both a major basin (Lake Superior) and a major upland (Abitibi Upland). Therefore, we attribute this advance of the Laurentide Ice Sheet to climatic forcing of the Younger Dryas event.

scholarly journals Sea cliff at Glowe: stratigraphy and absolute age chronology of the Jasmund Pleistocene sedimentary record

2019 ◽  
Vol 2 ◽  
pp. 43-50 ◽  
Author(s):  
Michael Kenzler ◽  
Heiko Hüneke
Keyword(s):  
Lacustrine Sediments ◽  
Ice Sheet ◽  
Sedimentary Record ◽  
Depositional Sequences ◽  
Scandinavian Ice Sheet ◽  
Stratigraphic Position ◽  
Absolute Age ◽  
Glacial Tills ◽  
Sea Cliff ◽  
Weichselian Glaciation

Abstract. Four remarkable Pleistocene cliff outcrops scattered across the peninsula of Jasmund exhibit the dynamics of the Scandinavian Ice Sheet during the Weichselian glaciation in this area. The investigated sites display up to 30 m thick sequences of glacial tills with intercalated (glaci)fluvial to (glaci)lacustrine sediments. Based on detailed lithofacies analyses and a physical age chronology, we trace the reconstruction of the depositional sequences and their corresponding stratigraphic position within the Weichselian record.

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