scholarly journals Origin of the Phoksundo Tal (lake), Dolpa district, western Nepal

1997 ◽  
Vol 15 ◽  
Author(s):  
H. Yagi
Keyword(s):  
Glacial Retreat ◽  
Last Glacial ◽  
Geomorphic Features ◽  
Glacial Advance ◽  
The Last Glacial

The typical geomorphic features of a landslide such as horseshoe shaped steep scarp and debris mounds are observed adjacent to the southeastern end of the Phoksundo Lake. The mounds consist of rock detritus ranging from cobble size to boulders of several tens of meters in diameter. The total volume of the debris deposited on the left side of the Bauli Gad is estimated to be about l.5 billion m3. The Phoksundo Lake is originated due to landslide damming resulting from a mountain collapse. The detritus is overlying the glacial drift. It implies that one of the glacial valley walls became unstable after the glacial retreat and collapsed over its own glacial drift, probably triggered by an earthquake. The mountain collapse may have occurred around 30 to 40 ka, just after the early substage of the glacial advance in the Last Glacial age.

Baetisca (Ephemeroptera: Baetiscidae) from the western interior of Canada with notes on the life cycle

1972 ◽  
Vol 50 (7) ◽  
pp. 1015-1017 ◽  
Author(s):  
D. M. Lehmkuhl
Keyword(s):  
Life Cycle ◽  
Drainage System ◽  
The South ◽  
Glacial Retreat ◽  
Last Glacial ◽  
The North ◽  
South Saskatchewan River ◽  
Dispersal Routes ◽  
The Last Glacial

The distributions of Baetisca obesa (Say) and B. bajkovi Neave in Canada are extended west to Saskatchewan and Alberta. Generic features of adults and nymphs and specific characters of the nymphs of the two species are illustrated. In the South Saskatchewan River nymphs of B. bajkovi hatch from the egg in August and September, they pass the winter under the ice, and adults emerge the following June and July. The Hudson's Bay drainage system was probably invaded by these species from the Mississippi drainage system during the last glacial retreat, since at various times dispersal routes in the form of rivers have been present from the southern refugium for migration to the north.

scholarly journals Human Settlements and the Last Deglaciation in the French Alps

Radiocarbon ◽  
1994 ◽  
Vol 36 (3) ◽  
pp. 345-357 ◽  
Author(s):  
Jacques Evin ◽  
Pierre Bintz ◽  
Guy Monjuvent
Keyword(s):  
Eastern Alps ◽  
Simultaneous Occurrence ◽  
Last Deglaciation ◽  
Glacial Retreat ◽  
French Alps ◽  
Dating Method ◽  
The Last Deglaciation ◽  
Rhone Valley ◽  
Glacial Advance ◽  
The Last Glacial

According to most geological and geomorphological studies, the maximal advance of the Würmian glaciers in the French Alps occurred at least before 40 ka bp and cannot be dated by 14C. Scientists believed that this dating method could be used for dating the last glacial advance and late deglaciation in the region. The scarce and scattered 14C dating results available from geological samples do not confirm an early (ca. 18 or 20 ka bp) age for the total cooling of the ice nor do they prove that residual ice sheets remained at low elevations. Attempting to solve this chronological problem, we compiled current archaeological knowledge of the oldest Late Paleolithic sites. A review of their 14C results shows that no site older than 15 ka bp (with Gravettian, Solutrean or early Magdalenian industries) can be found east of the Saône-Rhône Valley, even at low elevations. Only rare sites, dated to ca. 14.5 ka bp, may be found close to the mountain regions that were suddenly occupied around the beginning of the Bølling period (ca. 13.5 ka bp). Thus, it seems that the eastern Alps offer no evidence for direct association between glacial retreat and human settlement or simultaneous occurrence in early or late deglaciated areas.

scholarly journals Southwest Greenland shelf glaciation during MIS 4 more extensive than during the Last Glacial Maximum

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Marit-Solveig Seidenkrantz ◽  
Antoon Kuijpers ◽  
Jesper Olsen ◽  
Christof Pearce ◽  
Sofia Lindblom ◽  
...  
Keyword(s):  
Sea Water ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Glacial Cycle ◽  
Oxygen Isotope Stage ◽  
Last Glacial ◽  
Irminger Sea ◽  
West Greenland Current ◽  
Glacial Advance ◽  
The Last Glacial

Abstract Although geological and modelling evidence indicate that the last glacial inception in North America was in NE Canada, little is known about the glacial response of the nearby western Greenland Ice Sheet (GIS) during the glacial advance of marine oxygen isotope stage 4 (MIS4). Our multi-proxy study of a marine sediment core collected about 60 km southwest of the Outer Hellefisk Moraines demonstrates that in the southern Davis Strait region the most extreme Greenland shelf glaciation of the last glacial cycle occurred during MIS 4, with another prominent glacial advance at 37–33 kyr BP. During those periods the GIS likely reached the Outer Hellefisk Moraines in this area. Except for these two periods, our data suggest significant advection of relatively warm Irminger Sea Water by the West Greenland Current since MIS 4. This advection likely limited the extent of the MIS2 glaciation on the SW Greenland shelf. Decreased precipitation over southwestern Greenland predicted by atmospheric models as a downstream effect of a much larger MIS2 Laurentide Ice Sheet may have played an additional role.

Timing and extent of Late Pleistocene glaciation in the Chugach Mountains, Alaska

2021 ◽  
pp. 1-20
Author(s):  
Joshua D. Valentino ◽  
Lewis A. Owen ◽  
James A. Spotila ◽  
Jason M. Cesta ◽  
Marc W. Caffee
Keyword(s):  
Equilibrium Line Altitude ◽  
Glacial Retreat ◽  
Last Glacial Period ◽  
Geomorphic Mapping ◽  
Last Glacial ◽  
South Central ◽  
Reconstructed Temperature ◽  
Late Wisconsinan ◽  
Temperature Depression ◽  
The Last Glacial

Abstract Geomorphic mapping, landform and sediment analysis, and cosmogenic 10Be and 36Cl ages from erratics, moraine boulders, and glacially polished bedrock help define the timing of the Wisconsinan glaciations in the Chugach Mountains of south-central Alaska. The maximum extent of glaciation in the Chugach Mountains during the last glacial period (marine isotope stages [MIS] 5d through 2) occurred at ~50 ka during MIS 3. In the Williwaw Lakes valley and Thompson Pass areas of the Chugach Mountains, moraines date to ~26.7 ± 2.4, 25.4 ± 2.4, 18.8 ± 1.6, 19.3 ± 1.7, and 17.3 ± 1.5 ka, representing times of glacial retreat. These data suggest that glaciers retreated later in the Chugach Mountain than in other regions of Alaska. Reconstructed equilibrium-line altitude depressions range from 400 to 430 m for late Wisconsinan glacial advances in the Chugach Mountains, representing a possible temperature depression of 2.1–2.3°C. These reconstructed temperature depressions suggest that climate was warmer in this part of Alaska than in many other regions throughout Alaska and elsewhere in the world during the global last glacial maximum.

The Pit House in the Old World and in Native North America

1952 ◽  
Vol 18 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Hiroshi Daifuku
Keyword(s):  
North America ◽  
Western Europe ◽  
Upper Paleolithic ◽  
Old World ◽  
Artificial Structures ◽  
Last Glacial ◽  
Different Types ◽  
Native North America ◽  
Glacial Advance ◽  
The Last Glacial

The problem of the origin and distribution of semi-subterranean structures is an intriguing one. It is generally accepted that the semi-subterranean structure, earth lodge, or pit house, was one of a number of relatively unmodified traits of Old World origin found in North America. This paper reviews some of the literature on the pit house, and summarizes its development and distribution in the Eurasian and North American continents.Laymen, believing that early man habitually lived in caves, commonly use the stereotyped term “cave man” in referring to our early progenitors in the Old World. This assumption was an inevitable development since occupational sites in western Europe are predominantly caves or cave shelters. However, some European archaeologists have suggested such sites were seasonally occupied–that they were the winter habitations of man during the upper Paleolithic. There is reason to believe different types of shelters were used during warm seasons since engravings of tents or more substantial structures (tectiforms) have been found on the walls of caves and cave shelters. A number of European archaeologists including Breuil (1910), Clark (1939), Childe (1950), and others have accepted tectiforms as evidence of the existence of artificial structures in western Europe during the last glacial advance. Breuil has gone further and compared some of the tectiforms in the Font-de-Gaume, the Dordogne Valley of France, to the summer huts of Navahos described by Mendeleff in 1896.

scholarly journals Glazialtektonik im Weichselglazial Schleswig ­Holsteins und ihre Beziehungen zur Morphologie

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.

scholarly journals Maximum Glacier Extent of the Penultimate Glacial Cycle in the Upper Garonne Basin (Pyrenees): New Chronological Evidence

2021 ◽  
Author(s):  
Marcelo Vieira Fernandes ◽  
Marc Oliva ◽  
Gonçalo Vieira ◽  
David Palacios ◽  
José María Fernández-Fernández ◽  
...  
Keyword(s):  
Cosmic Ray ◽  
Mountain Range ◽  
Glacial Cycle ◽  
Terminal Moraine ◽  
Last Glacial ◽  
Exposure Ages ◽  
New Evidence ◽  
Eemian Interglacial ◽  
Glacial Advance ◽  
The Last Glacial

Abstract The Upper Garonne Basin included the longest glacier in the Pyrenees during the Late Pleistocene. During major glacial advances, the Garonne palaeoglacier flowed northwards along ~ 90 km from peaks of the axial Pyrenees exceeding 2,800-3,000 m until the foreland of this mountain range at the Loures-Barouse-Barbazan basin, at only 420–440 m. Here, the palaeoglacier formed a terminal moraine complex that is examined in this work. Based on geomorphological observations and a 12-sample dataset of 10Be Cosmic-Ray Exposure (CRE) ages, we have constrained the timing of the maximum glacial extent as well as the onset of the deglaciation from the end of the Last Glacial Cycle (LGC). Chronological data shows evidence that the external moraines in this basin were abandoned by the ice at the end of the Penultimate Glacial Cycle (PGC) and the onset of the Eemian Interglacial, at ~ 129 ka. No evidence of subsequent glacial advances or standstills occurred during the LGC in this basin were found, as the few existing datable boulders provided in the internal moraine showed inconsistent ages, thus probably being affected by post-glacial processes. The terminal basin was already deglaciated during the global Last Glacial Maximum at 24 − 21 ka, as revealed by exposure ages of polished surfaces at the confluence of the Garonne-La Pique valleys, 13 km south of the entrance of the Loures-Barousse-Barbazan basin. This study introduces the first CRE ages in the Pyrenees for the glacial advance occurred during the PGC and provides also new evidence that glaciers had already significantly shrunk during the LGM.

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