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.

Stratigraphy and structure of Pleistocene collapse in the Regina Low, Saskatchewan, Canada

2002 ◽  
Vol 39 (9) ◽  
pp. 1411-1423 ◽  
Author(s):  
E A Christiansen ◽  
E Karl Sauer
Keyword(s):  
Late Pleistocene ◽  
Middle Devonian ◽  
Upper Cretaceous ◽  
Early Pleistocene ◽  
Middle Pleistocene ◽  
Pierre Shale ◽  
Hydraulic Gradients ◽  
Group A ◽  
Structural Closure

The Regina Low is a collapse structure, formed as a result of dissolution of salt from the Middle Devonian Prairie Evaporite Formation. In this study, collapse has affected the Upper Cretaceous Pierre Shale and the Ardkenneth and Snakebite members of the Bearpaw Formation of the Montana Group; the Mennon, Dundurn, and Warman formations of the Sutherland Group; and the Floral and Battleford formations of the Saskatoon Group. A structural closure of 125–175 m approximates the thickness of the Middle Devonian Prairie Evaporite Formation. In the Early Pleistocene, about 54 m of collapse took place in eastern Regina accounting for the preservation of Snakebite Member. Major collapses of about 58 and 86 m took place in northern Regina during deposition of Middle Pleistocene, pre-Illinoian Dundurn Formation. The final major collapse of about 127 m took place in northeastern Regina between deposition of the lower and upper tills of the Floral Formation. Eighty-seven metres of this collapse took place during deposition of the Late Pleistocene, interglacial, Sangamon Pasqua Member of the Floral Formation. The Pleistocene fill in the Regina Low collapse structure suggests that collapse took place when dissolution of salt from the Prairie Evaporite Formation was accelerated by high hydraulic gradients created by the surcharge pressures of the glaciers.

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.

scholarly journals A geological concept of the map sheet Rønde based on dynamic structures

1987 ◽  
Vol 8 ◽  
pp. 1-59
Author(s):  
Kaj Strand Petersen ◽  
Leif Aabo Rasmussen
Keyword(s):  
Late Pleistocene ◽  
Middle Pleistocene ◽  
The South ◽  
The Holocene ◽  
Dynamic Structures ◽  
Geological Concept ◽  
Weichselian Glaciation ◽  
Glacial Advance

During the mapping of the map sheet Rønde 1315 II an important kineto-stratigraphical frame for the Late Middle Weichselian in the central part of Denmark was demonstrated. Quaternary units are deposited on Paleogene sediments consisting of clayey Eocene-Paleocene strata to the southwest and Lower Paleocene-Danian limestone to the northeast. Middle Pleistocene till units are found as erosional remnants on the Prequaternary surface. The Late Pleistocene deposits are described within the kineto-stratigraphical concept, showing an older unit related to a glacial advance from the northeast and a younger one from the south, both belonging to the Late Middle Weichselian glaciation. Prominent extramarginal outwash sand deposits cover - the central part of the map sheet as a part of the drift unit from the south. The low-lying areas have beeen covered by the sea during the Holocene from the transgression in Early Atlantic up to the end of Subboreal. In the Subatlantic, freshwater deposits were formed, later covered by peat.

Hominin transition to Upper Pliocene

2017 ◽  
Author(s):  
Francisco J. Ayala ◽  
Camilo J. Cela-Conde
Keyword(s):  
Brain Development ◽  
Late Pleistocene ◽  
Technological Progress ◽  
Homo Sapiens ◽  
Middle Pleistocene ◽  
Evolutionary Significance ◽  
Australopithecus Afarensis ◽  
Phylogenetic Significance ◽  
Homo Neanderthalensis ◽  
Surprising Discovery

This chapter analyzes the transition of the hominins from the Middle Pleistocene to the Late Pleistocene. Two alternative models are explored, the “Multiregional Hypothesis” (MH) and the “Replacement Hypothesis,” and how each model evaluates the existing relationships between the taxa Homo neanderthalensis and Homo sapiens. Next is the investigation of the transitional (or “archaic,” if this grade is taken into account) exemplars found in Europe, Africa, and Asia and their evolutionary significance. In particular, the comparison between H. erectus and H. sapiens in China and Java is investigated, as the main foundation of the MH. The chapter ends with the surprising discovery of Homo floresiensis and its description and interpretations concerning its taxonomic and phylogenetic significance. The correlation between brain development and technological progress is at odds with the attribution of perforators, microblades, and fishing hooks to a hominin with a small cranial volume, similar to that of Australopithecus afarensis.

Sierraceratops turneri, a new chasmosaurine ceratopsid from the Hall Lake Formation (Upper Cretaceous) of south-central New Mexico

2021 ◽  
pp. 105034
Author(s):  
Sebastian G. Dalman ◽  
Spencer G. Lucas ◽  
Steven E. Jasinski ◽  
Nicholas R. Longrich
Keyword(s):  
New Mexico ◽  
Upper Cretaceous ◽  
South Central ◽  
Lake Formation

New South African Review 3: The second phase – tragedy or farce? (John Daniel, Prishani Naidoo, Devan Pillay and Roger Southall, eds)

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Dirk Kotzé
Keyword(s):  
South Africa ◽  
South African ◽  
Social Practice ◽  
New South ◽  
Second Phase ◽  
Human Sciences ◽  
The South ◽  
Negotiated Settlement ◽  
The Third ◽  
Direct Competition

As the title indicates this publication is the third issue in a series of reviews. The first issue was subtitled 2010: Development or decline? (2010) and the second was New paths, old promises? (2011). These publications are edited in the Department of Sociology at Wits University as part of its Strategic Planning and Allocation of Resources Committee (SPARC) Programme. The series is intended to be a revival of the South African Review edited by the South African Research Service and published by Ravan Press in the 1980s and early 1990s. Arguably one of the best known of these series was issue seven edited by Steven Friedman and Doreen Atkinson, The Small Miracle: South Africa's negotiated settlement (1994). The latest publication should also be seen as direct competition for the Human Sciences Research Council's (HSRC) regular publication, State of the Nation. The New South African Review 3 is organised into four parts, namely Party, Power and Class; Ecology, Economy and Labour; Public Policy and Social Practice; and South Africa at Large. The four editors introduce each of the sections, consisting of 16 chapters in total. Thebook's format appears to be that of a yearbook but it is not linked to a specific year. It is therefore not in the same category as for example the South African Institute of Race Relations' annual South Africa Survey. The Review is organised around a theme, albeit very general in its formulation, and in the case of the third issue it is also not applicable to all its chapters. At the same time, though, it is not a yearbook as the choice of chapters and their foci are on the latest developments. 

Facies Composition and Stratigraphic Position of the Quaternary Upper Yenisei Sequence in the Tuva and Minusa Depressions

2021 ◽  
Vol 62 (10) ◽  
pp. 1127-1138
Author(s):  
I.D. Zol’nikov ◽  
I.S. Novikov ◽  
E.V. Deev ◽  
A.V. Shpansky ◽  
M.V. Mikharevich
Keyword(s):  
Late Pleistocene ◽  
Lacustrine Sediments ◽  
Alluvial Fan ◽  
Luminescence Dating ◽  
Middle Pleistocene ◽  
Mountainous Area ◽  
Gorny Altai ◽  
Stratigraphic Position ◽  
Geochronological Dating ◽  
Current Ripples

Abstract —The paper concerns the sediment sequence, which is widespread in the Yenisei valley and in the Tuva and Minusa depressions and also present in the valleys of the southern Chulym plain. The sediments of this sequence were previously described as “Neogene mud-shedding”, as well as moraines, alluvial fan deposits, alluvium of Middle Pleistocene high terraces, and lacustrine sediments. The giant ripple marks on the Upper Yenisei terraces was commonly interpreted as ribbed moraines; however, in recent studies, these ridges have been repeatedly referred to as marks of giant current ripples. Besides, some recently published papers provide description of geology of this sequence fragments suggesting its deposition by cataclysmic floods. Geomorphological analysis of the area shows Pleistocene glaciers to have been localized within the medium–high mountainous areas. The glaciers did not reach the Tuva and Minusa depressions and occupied large areas only in the Todzha basin and on the periphery of the Darkhat basin, forming a glacial dam at its outlet, which resulted in glacial-dammed lakes filling the basin completely. These lakes outburst, and the resultant flooding led to the deposition of megaflood sediments, which we refer to here as the Upper Yenisei sediment sequence. A detailed analysis of its facies architecture revealed similarity of these sediments to those of the Sal’dzhar and Inya sequences in Gorny Altai. Most of the Upper Yenisei megaflood sediments are localized in topographic lows of the Tuva and Minusa depressions. Beyond the Altai–Sayan mountainous area, the megaflood sediments of the Upper Yenisei sequence compose high terraces of the Yenisei, Chulym, Chet’, and Kiya rivers in the southern Chulym plain. The formation of Upper Yenisei sequence dates to the first half of the Late Pleistocene, inasmuch as it contains inset alluvial sediments of the second terrace of the Yenisei River. The available data allow suggesting that the Upper Yenisei sequence formed in the first Late Pleistocene regional glaciation. The Sal’dzhar sequence in Gorny Altai and the fourth terrace of the Ob’ River on the Fore-Altai plain are stratigraphic analogs of the Upper Yenisei sequence. The Upper Yenisei and Sal’dzhar sequences can thus be considered future regional markers serving as a link for the local stratigraphic schemes of the Altai–Sayan mountainous area and adjacent West Siberian plains. The results obtained call for verification by geochronological dating, first of all, by modern luminescence dating methods covering a wider chronological interval than radiocarbon dating.

Two new Banksia species from pleistocene sediments in western Tasmania

1991 ◽  
Vol 4 (3) ◽  
pp. 499 ◽  
Author(s):  
GI Jordan ◽  
RS Hill
Keyword(s):  
Plant Species ◽  
Late Pleistocene ◽  
Environmental Changes ◽  
Middle Pleistocene ◽  
Extinct Species ◽  
The Third ◽  
Taxonomic Groups

Subtribe Banksiinae of the Proteaceae was diverse in Tasmania in the early and middle Tertiary, but is now restricted to two species, Banksia marginata and B. serrata. Rapid and extreme environmental changes during the Pleistocene are likely causes of the extinction of some Banksia species in Tasmania. Such extinctions may have been common in many taxonomic groups. The leaves and infructescences of Banksia kingii Jordan & Hill, sp. nov. are described from late Pleistocene sediments. This is the most recent macrofossil record of a now extinct species in Tasmania. Banksia kingii is related to the extant B. saxicola. Banksia strahanensis Jordan & Hill, sp. nov. (known only from a leaf and leaf fragments and related to B. spinulosa) is described from Early to Middle Pleistocene sediments in Tasmania. This represents the third Pleistocene macrofossil record of a plant species which is now extinct in Tasmania.

Preliminary investigation of a late Wisconsinan fauna from K1 cave, Queen Charlotte Islands (Haida Gwaii), Canada

2004 ◽  
Vol 62 (1) ◽  
pp. 105-109 ◽  
Author(s):  
Carolyn L. Ramsey ◽  
Paul A. Griffiths ◽  
Daryl W. Fedje ◽  
Rebecca J. Wigen ◽  
Quentin Mackie
Keyword(s):  
Late Pleistocene ◽  
Environmental Conditions ◽  
Preliminary Investigation ◽  
Skeletal Remains ◽  
Human Migration ◽  
Early Holocene ◽  
Haida Gwaii ◽  
Queen Charlotte Islands ◽  
Late Wisconsinan ◽  
Early Human

Recent investigations of a limestone solution cave on the Queen Charlotte Islands (Haida Gwaii) have yielded skeletal remains of fauna including late Pleistocene and early Holocene bears, one specimen of which dates to ca. 14,400 14C yr B.P. This new fossil evidence sheds light on early postglacial environmental conditions in this archipelago, with implications for the timing of early human migration into the Americas.

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