Glaciation of the Torngat Mountains, Northern Labrador

ARCTIC ◽  
1957 ◽  
Vol 10 (2) ◽  
pp. 66 ◽  
Author(s):  
J.D. Ives
Keyword(s):  
North America ◽  
Ice Sheet ◽  
Field Work ◽  
Glacial Period ◽  
Large Area ◽  
International Union ◽  
Northeastern North America ◽  
Glacial Periods

Considers role of these mountains in glaciation of Labrador-Ungava, assessing particularly events in late-Wisconsin times with respect to final disappearance of both continental and local ice masses. Conflicting theories are discussed, and evidence presented, based on physiography and findings from summer 1956 field work, including unmistakable erratics on summits at 4,000-5,000 ft. The highest summits were completely submerged by eastward moving continental ice during the Wisconsin glaciation; local glaciers never reached significant dimensions; rapid melting in situ of thick masses of ice occurred during the final Wisconsin stages. Two or three separate glacial periods are recognized from the morphology of the area. Instantaneous glaciation of a large area of the Labrador-Ungava Plateau probably initiated a continental ice sheet in northeastern North America at the onset of each glacial period. Also pub. in International Union of Geodesy and Geophysics, Association of Scientific Hydrology, 11th assembly report of proceedings 1958, v. 4, p. 372-86.

An Archaeological Survey of Caves in Washington

1954 ◽  
Vol 19 (4) ◽  
pp. 387-389
Author(s):  
Earl Swanson ◽  
Alan Bryan
Keyword(s):  
North America ◽  
Field Work ◽  
Archaeological Research ◽  
Archaeological Survey ◽  
Large Area ◽  
Columbia Plateau ◽  
Long Period ◽  
Western Washington ◽  
The University ◽  
Private Collections

During a long period of the time when archaeological research was in progress in other areas of North America, the Columbia Plateau and western Washington lay relatively untouched and unknown. Only recently have systematic studies been undertaken by the University of Washington.The archaeological survey of cave sites in Washington, during the summer of 1952, is a part of those studies. The plan was to locate as many caves as possible, to determine if they had been occupied aboriginally, and to evaluate them with an eye to future excavation.Prior to the field work, reports had been received of caves in various parts of Washington, but the total was small, and we had little expectation of swelling the known number. Many of these had been learned of through newspaper clippings and letters, and from amateur activities. The problem, then, was not simply to examine a few choice caves for testing and excavation, but of surveying a large area in order to initiate an immediate program of excavation to save what remained. In addition to the survey of the caves, the University provided money for the examination of private collections.

scholarly journals Inter-glacial isolation caused divergence of cold-adaptedspecies: the case of the snow partridge

2021 ◽  
Author(s):  
Hongyan Yao ◽  
Yanan Zhang ◽  
Zhen Wang ◽  
Gaoming Liu ◽  
Quan Ran ◽  
...  
Keyword(s):  
Population Size ◽  
Hengduan Mountains ◽  
Glacial Period ◽  
Ecological Niche Models ◽  
Effective Population ◽  
Cold Adapted ◽  
Climatic Oscillations ◽  
Glacial Periods ◽  
High Elevations

Abstract Deciphering the role of climatic oscillations in species divergence helps us understand the mechanisms that shape global biodiversity. The cold-adapted species may have expanded their distribution with the development of glaciers during glacial period. With the retreat of glaciers, these species were discontinuously distributed in the high-altitude mountains and isolated by geographical barriers. However, the study that focuses on the speciation process of cold-adapted species is scant. To fill this gap, we combined population genetic data and ecological niche models (ENMs) to explore divergence process of snow partridge (Lerwa lerwa). Lerwa lerwa is a cold-adapted bird that is distributed from 4,000 to 5,500 m. We found 2 genetic populations within L. lerwa, and they diverged from each other at about 0.40–0.44 million years ago (inter-glacial period after Zhongliangan glaciation). The ENMs suggested that L. lerwa expanded to the low elevations of the Himalayas and Hengduan mountains during glacial period, whereas it contracted to the high elevations, southern of Himalayas, and Hengduan mountains during inter-glacial periods. Effective population size trajectory also suggested that L. lerwa expanded its population size during the glacial period. Consistent with our expectation, the results support that inter-glacial isolation contributed to the divergence of cold-adapted L. lerwa on Qinghai-Tibetan Plateau. This study deepens our understanding of how climatic oscillations have driven divergence process of cold-adapted Phasianidae species distributed on mountains.

Conducting Oxide Electrode to Mitigate Mechanical Instability (Bubble Formation) during Operation of La1-xSrxMnO3 (LSMO) based RRAM

2013 ◽  
Vol 1507 ◽  
Author(s):  
Rajashree Nori ◽  
N. Ravi Chandra Raju ◽  
Naijo Thomas ◽  
Neeraj Panwar ◽  
Pankaj Kumbhare ◽  
...  
Keyword(s):  
Bubble Formation ◽  
Mechanical Damage ◽  
Mechanical Instability ◽  
Electrical Measurements ◽  
Large Area ◽  
Lsmo Film ◽  
Oxide Electrodes ◽  
Switching Behaviour

ABSTRACTThe role of field-induced electrochemical migration oxygen ions in switching behaviour of LSMO films is established through I-V measurements under various top electrode device configurations. We report observation of bubbling, mechanical damage and delamination of top electrode in LSMO-based large area RRAM devices. Polarity dependence of this phenomenon, as observed in-situ during electrical measurements, reveals O-evolution to be the likely cause for such electrode damage. The effect of this phenomenon on switching behaviour of devices with reactive as well as inert top electrodes is presented. To mitigate the electrode integrity issue, we explore the use of conducting oxide electrodes on the active LSMO film.

Possible Causes of the Variability of Postglacial Uplift in North America

1971 ◽  
Vol 1 (4) ◽  
pp. 522-531 ◽  
Author(s):  
Richard H. Fillon
Keyword(s):  
North America ◽  
Ice Sheet ◽  
Tectonic Activity ◽  
Laurentide Ice Sheet ◽  
Uplift Rate ◽  
Geophysical Research ◽  
Northeastern North America ◽  
Isostatic Uplift ◽  
Uplift Rates ◽  
Consistent Manner

Postglacial uplift data from 33 sites in northeastern North America reveal that during the period from 11,000 years B.P. to 7000 years B.P., glacio-isostatic uplift rates varied in a consistent manner with distance from the former margin of the Laurentide Ice Sheet. The consistent trends of these uplift rate variations with distance from the former ice sheet margin suggest that they were not the result of changes in the rate of ice sheet retreat or local tectonic activity. They instead may have resulted from rebound affected significantly by the earth's viscosity at a depth approximately equal to the wavelength of isostatic deformation [McConnell, R.K., Jr., Journal of Geophysical Research70, 5171 (1965)]. Extremely high viscosities below 600 km, however, probably provide the lower limit for this relationship.

Black Bears and the Iroquoians

Bears ◽  
2020 ◽  
pp. 138-159
Author(s):  
Christian Gates St-Pierre ◽  
Claire St-Germain ◽  
Louis-Vincent Laperrière-Désorcy
Keyword(s):  
North America ◽  
Ursus Americanus ◽  
Black Bear ◽  
Black Bears ◽  
Minor Role ◽  
Northeastern North America ◽  
Projectile Points ◽  
Economic Role ◽  
Faunal Assemblages

The study presented in this chapter uses archaeological and ethnohistorical data to discuss the role of black bears (Ursus americanus) among Pre-Contact Iroquoian societies from Northeastern North America. This role is proving to be complex and multifaceted, and the analysis of the archaeological and ethnohistorical records provide contradictory conclusions. According to the ethnohistorical documents considered in this study, black bear appears to be predominantly mentioned in subsistence and hunting contexts. In contrast, bones from black bear have been identified in a majority of Iroquoian faunal assemblages, but always in small numbers, indicating a ubiquitous, yet minor role for black bear in Pre-Contact Iroquoian foodways. Moreover, ethnonyms, myths, and legends also suggest that the symbolic and identity dimensions of black bear outweighed their economic role. The results of the ZooMS analysis of a set of Iroquoian bone projectile points is especially revealing in this respect.

New Perspectives on Meadowood Trade Items

2011 ◽  
Vol 76 (1) ◽  
pp. 41-79 ◽  
Author(s):  
Karine Taché
Keyword(s):  
Spatial Distribution ◽  
North America ◽  
Raw Materials ◽  
Archaeological Sites ◽  
Northeastern North America ◽  
Corporate Groups ◽  
Early Woodland ◽  
Interaction Spheres ◽  
The Creation

In Early Woodland times, the creation of vast interaction spheres resulted in the widespread circulation of various objects and raw materials across northeastern North America. In this article, I discuss the contexts and spatial distribution of Meadowood trade items from over 240 archaeological sites. Traditionally viewed by William A. Ritchie as cult-related items, Meadowood artifacts have subsequently been interpreted as participating in a risk-buffering strategy. Alternatively, I present arguments supporting the role of Meadowood artifacts as part of a strategy used by a few individuals or corporate groups to increase their status through privilege access to rare and highly valued goods. Socially valued goods can be used in multiple ways and documenting this complexity is a prerequisite to understanding the mechanisms underlying the circulation of goods within the Meadowood Interaction Sphere, the structure of the network, and the incentives of the participating groups. This article stresses the need to move beyond the dichotomy between utilitarian/subsistence-related goods and non-utilitarian/ritual artifacts.

Plants and Subsistence during the Fluted-Point Period of the Northeast

2021 ◽  
pp. 1-9
Author(s):  
Nathaniel R. Kitchel ◽  
Madeline E. Mackie
Keyword(s):  
North America ◽  
Probability Distributions ◽  
Diet Breadth ◽  
Radiocarbon Date ◽  
Northeastern North America ◽  
Plant Foods ◽  
Macrobotanical Remains ◽  
Caribou Hunting

The role of plant foods during the fluted-point period (FPP) of North America is contested. Central to this debate is whether the scarcity of FPP macrobotanical materials stems from poor preservation of archaeological features and the macrobotanical remains they might contain or from the limited use of plants during the FPP. Employing summed probability distributions of radiocarbon date frequencies in northeastern North America, we find that FPP hearths are as common as expected, given the small number of well-dated FPP sites in the region. A second comparison shows that northeastern FPP hearths contain macrobotanical remains at a higher frequency than hearths from a region with better preservation and where small seeds formed a part of the diet. The macrobotanical materials so far recovered from FPP hearths in the Northeast show that plant foods contributed to diets during the FPP but that the plant diet breadth was relatively narrow, consistent with a specialized caribou hunting lifeway.

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