Radiocarbon dates on peat and tree remains from James Bay area, subarctic Quebec

1979 ◽  
Vol 9 (1) ◽  
pp. 125-129 ◽  
Author(s):  
Jean-Claude Dionne
Keyword(s):  
Late Glacial ◽  
Glacial Lake ◽  
Before Present ◽  
James Bay ◽  
Radiocarbon Dates ◽  
Bay Area ◽  
Lake Ojibway ◽  
James Bay Lowlands

14C dates on peat and tree remains from the southern part of James Bay Lowlands, subarctic Quebec, indicate that forests and peatland conditions began at least 1000 years after the deglaciation of the area. Inception of forest and organic deposition in bogs varies within the main geological events of the late-glacial and postglacial times in the area: the drainage of glacial Lake Ojibway, the Tyrrell Sea transgression, and the emergence. The oldest age recorded for the beginning of peat deposition is 6890 ± 120 years before present (BP) at an elevation of 240 m and the youngest age is 3830 ± 120 years BP at an elevation of 60 m. A delay ranging from 400 to 900 years between forest occupation and the establishment of bog conditions is recorded.

A Late Pleistocene plant-bearing deposit in Currie Township, near Matheson, Ontario

1979 ◽  
Vol 16 (5) ◽  
pp. 1130-1136 ◽  
Author(s):  
W. E. Brereton ◽  
J. A. Elson
Keyword(s):  
River Basin ◽  
Late Pleistocene ◽  
Glacial Lake ◽  
Fossil Plants ◽  
Fossil Plant ◽  
James Bay ◽  
Plant Detritus ◽  
Lake Ojibway ◽  
Moose River ◽  
James Bay Lowlands

Two overburden test holes drilled to bedrock in Currie Township, southwest of Matheson, Ontario, penetrated stratified beds containing fossil plant detritus resting on an oxidized substrate, which are between two till sheets underlying glacial Lake Ojibway-Barlow varved clays. The fossil plants, chiefly mosses, represent an environment that is common in the region today, and are radiocarbon dated (GSC-2148) as older than 37000 years. The interglacial deposit is tentatively correlated with the Missinaibi Formation in the Moose River basin of the James Bay lowlands, probably of Sangamon age.

Some problems of late Wisconsin history and geochronology in southeastern Ontario

1980 ◽  
Vol 17 (3) ◽  
pp. 361-381 ◽  
Author(s):  
J. Terasmae
Keyword(s):  
Lake Ontario ◽  
Lake Huron ◽  
Glacial Lake ◽  
Radiocarbon Dates ◽  
Ottawa River ◽  
Bay Area ◽  
The North ◽  
Lake Algonquin ◽  
Surficial Deposits ◽  
Glacial Lake Algonquin

Palynological studies and radiocarbon dating of sediments from about 20 lakes and bogs in southeastern Ontario have been used to establish a palynostratigraphic sequence of six pollen zones extending to approximately 12 000 years BP and indicating that deglaciation occurred between 12 500 and 11 500 years BP, probably during the Two Creeks interstadial interval.The glacial Lake Iroquois existed in the Lake Ontario basin from about 12 500 – 11 800 years BP while the Lake Ontario ice lobe was retreating northeastward, and the Kirkfield – Fenelon Falls outlet from glacial Lake Algonquin (in the Georgian Bay – Lake Huron basin) to Lake Iroquois opened about 12 000 years ago when the Dummer Moraine was deposited as a stagnant ice disintegration feature south of the Algonquin and Haliburton Highlands.Most radiocarbon dates (about 25) on marine shells, whale bone, and algae from Champlain Sea beach deposits are in the range of 10 000 – 11 800 years BP, indicating that the Champlain Sea episode is younger than glacial Lake Iroquois. However, a few Champlain Sea dates are older than 12 000 years BP and present an unresolved problem in geochronological correlation because they conflict with proposed deglaciation histories for southeastern Ontario.Late Wisconsin ice marginal positions are poorly known in southeastern Ontario and comprise another problem for further study.The end of glacial Lake Algonquin phase (the main drainage event in the North Bay area) probably occurred between 10 800 and 10 500 years BP, after the Champlain Sea had reached its maximum western limit in the Pembroke area (upper Ottawa River valley) as indicated by stratigraphic relationships of surficial deposits.

Evidence of late glacial paleoseismicity from submarine landslide deposits within Lac Dasserat, northwestern Quebec, Canada

2016 ◽  
Vol 86 (2) ◽  
pp. 184-199 ◽  
Author(s):  
Gregory R. Brooks
Keyword(s):  
Ice Sheet ◽  
Late Glacial ◽  
Relative Strength ◽  
Submarine Landslide ◽  
Laurentide Ice Sheet ◽  
Glacial Lake ◽  
Event Horizons ◽  
Lake Ojibway

AbstractAn integrated seismo- and chronostratigraphic investigation at Lac Dasserat, northwestern Quebec, identified 74 separate failures within eight event horizons. Horizons E and B, and H and G have strong or moderately-strong multi-landslide signatures, respectively, composed of 11-23 failures, while horizons F, D, C, and A have minor landslide signatures consisting of a single or pair of deposit(s). Cores collected at six sites recovered glacial Lake Ojibway varve deposits that are interbedded with the event horizons. The correlation of the varves to the regional Timiskaming varve series allowed varve ages or ranges of varve ages to be determined for the event horizons. Horizons H, G, E, and B are interpreted to be evidence of paleoearthquakes with differing levels of interpretative confidence, based on the relative strength of the multi-landslide signatures, the correlation to other disturbed deposits of similar age in the region, and the lack or possibility of alternative aseismic mechanisms. The four interpreted paleoearthquakes occurred between 9770 ± 200 and 8470 ± 200 cal yr BP, when glacial Lake Ojibway was impounded behind the Laurentide Ice Sheet during deglaciation. They probably represent an elevated period of seismicity at deglaciation that was driven by crustal unloading.

scholarly journals New records and AMS radiocarbon dates on Quaternary Walrus ( Odobenus Rosmarus ) from New Brunswick

2002 ◽  
Vol 51 (1) ◽  
pp. 107-111 ◽  
Author(s):  
Randall F. Miller
Keyword(s):  
New Brunswick ◽  
New Records ◽  
Temporal Distribution ◽  
Late Glacial ◽  
Bay Of Fundy ◽  
Eastern Canada ◽  
Radiocarbon Dates ◽  
Odobenus Rosmarus ◽  
Sand And Gravel ◽  
Past Summer

Abstract Walrus fossils are occasionally recovered during scallop dragging in the Bay of Fundy and from sand and gravel deposits along the coastline of New Brunswick in eastern Canada. Six new fossils and four new AMS radiocarbon dates significantly increase the information concerning late-glacial to postglacial walrus in New Brunswick. Dates range from about 12 800 BP to 2 900 BP, almost half falling between 9 000 and 10 000 BP. Temporal distribution of walrus, compared to estimates of past summer sea surface temperature, suggest that in the Bay of Fundy walrus occurred in waters ranging from 12 to 15° C.

Pre-LGM open-water conditions south of the Drygalski Ice Tongue, Ross Sea, Antarctica

2007 ◽  
Vol 19 (3) ◽  
pp. 373-377 ◽  
Author(s):  
Furio Finocchiaro ◽  
Carlo Baroni ◽  
Ester Colizza ◽  
Roberta Ivaldi
Keyword(s):  
Ross Sea ◽  
Open Water ◽  
Radiocarbon Dates ◽  
The Core ◽  
Bay Area ◽  
Terra Nova Bay ◽  
Insoluble Organic Matter ◽  
Victoria Land ◽  
Marine Isotope Stage 3 ◽  
Raised Beaches

AbstractA marine sediment core collected from the Nordenskjold Basin, to the south of the Drygalski Ice Tongue, provides new sedimentological and chronological data for reconstructing the Pleistocene glacial history and palaeoenvironmental evolution of Victoria Land. The core consists of an over consolidated biogenic mud covered with glacial diamicton; Holocene diatomaceous mud lies on top of the sequence. Radiocarbon dates of the acid insoluble organic matter indicate a pre-Last Glacial Maximum age (>24kyr) for the biogenic mud at the base of the sequence. From this we can presume that at least this portion of the western Ross Sea was deglaciated during Marine Isotope Stage 3 and enjoyed open marine conditions. Our results are consistent with recent findings of pre-Holocene raised beaches at Cape Ross and in the Terra Nova Bay area.

Late-glacial flow patterns, deglaciation, and postglacial emergence of south-central Baffin Island and the north-central coast of Hudson Strait, eastern Canadian Arctic

1996 ◽  
Vol 33 (11) ◽  
pp. 1499-1510 ◽  
Author(s):  
William F. Manley
Keyword(s):  
High Tide ◽  
Ice Sheet ◽  
Late Glacial ◽  
Flow Patterns ◽  
Sediment Provenance ◽  
Radiocarbon Dates ◽  
Ice Cap ◽  
The North ◽  
South Central ◽  
Ice Stream

New georaorphic, sedimentologic, and chronologic data are used to reconstruct late Quaternary ice-sheet flow patterns, deglaciation, and isostatic uplift along the largest marine trough connecting the Laurentide Ice Sheet with the North Atlantic Ocean. The Lake Harbour region was targeted for study given its potential to record flow from several ice-dispersal centers. Striations and sediment provenance indicators define flow patterns. Thirty-four radiocarbon dates constrain a chronology of events. Centuries or millennia(?) before deglaciation, a southeast-flowing ice stream impinged on southernmost Big Island, as recorded by a single striation site and delimited in extent by geomorphic evidence of cold-based ice. During the Cockburn Substagc (9000–8000 BP), the region was scoured by southward to southwestward flow from an ice cap on Meta Incognita Peninsula, as recorded by 60 striation sites along 200 km of coastline. Carbonate erratics are uncommon in till above the marine limit. Where present, they suggest that southward flow reworked older drift. At about 8200 BP, the area was dcglaciated, and the marine limit was established at elevations of 67–141 m above high tide. Iceberg calving and sediment discharge from an ice margin in Ungava Bay, Hudson Bay, or Foxe Basin then blanketed the area with limestone-rich glaciomarinc sediment. Afterward, the region experienced slow but sustained emergence. The data revise the maximum lateral extent of a Late Wisconsinan ice stream in Hudson Strait and emphasize the extent of a late-glacial ice cap on western Meta Incognita Peninsula.

The James Bay H.E.P. Complex

1983 ◽  
Vol 2 (2) ◽  
pp. 123-131 ◽  
Author(s):  
W. Hamley
Keyword(s):  
North America ◽  
Economic Recession ◽  
The Other ◽  
Energy Market ◽  
James Bay ◽  
Bay Area ◽  
Planning Decisions ◽  
Major Producer ◽  
The Right ◽  
Installed Capacity

Québec is a major producer of hydro-electricity in North America. In 1971 a massive undertaking was announced to add to this output by tapping the power of the rivers in the James Bay area of the province. There were to be five complexes—La Grande I, La Grande II, NBR, Baleine and Caniapiscau which, when completed in the 1990s, would add nearly 40 000 MW to installed capacity. Work is just reaching completion on La Grande I, the largest of the complexes, but in 1982 it was decided not to proceed with the other four, at least for the immediate future. Such a situation has arisen largely as a consequence of a very volatile period in the energy market coinciding with economic recession which has been very severe in Quebec. It is suggested that part of the solution to the province's problems could come about by utilizing James Bay H.E.P to stimulate local electricity intensive industries as well as earning income through electricity exports. However present uncertainties make planning decisions very difficult and the halting of construction, despite there being no problems of funding currently, seems a correct policy under prevailing conditions. It could be that the James Bay developments are the right scheme at the wrong time.

scholarly journals Tree-Ring Records of Near-Younger Dryas Time in Central North America—Preliminary Results from the Lincoln Quarry Site, Central Illinois, Usa

Radiocarbon ◽  
2004 ◽  
Vol 46 (2) ◽  
pp. 933-941 ◽  
Author(s):  
Irina P Panyushkina ◽  
Steven W Leavitt ◽  
Alex Wiedenhoeft ◽  
Sarah Noggle ◽  
Brandon Curry ◽  
...  
Keyword(s):  
North America ◽  
Tree Ring ◽  
Environmental Changes ◽  
Ring Width ◽  
Younger Dryas ◽  
Late Glacial ◽  
Radiocarbon Dates ◽  
Initial Sampling ◽  
Central Illinois ◽  
A Site

The abrupt millennial-scale changes associated with the Younger Dryas (YD) event (“chronozone”) near the dawn of the Holocene are at least hemispheric, if not global, in extent. Evidence for the YD cold excursion is abundant in Europe but fairly meager in central North America. We are engaged in an investigation of high-resolution environmental changes in mid-North America over several millennia (about 10,000 to 14,000 BP) during the Late Glacial–Early Holocene transition, including the YD interval. Several sites containing logs or stumps have been identified and we are in the process of initial sampling or re-sampling them for this project. Here, we report on a site in central Illinois containing a deposit of logs initially thought to be of YD age preserved in alluvial sands. The assemblage of wood represents hardwood (angiosperm) trees, and the ring-width characteristics are favorable to developing formal tree-ring chronologies. However, 4 new radiocarbon dates indicate deposition of wood may have taken place over at least 8000 14C yr (6000–14,000 BP). This complicates the effort to develop a single floating chronology of several hundred years at this site, but it may provide wood from a restricted region over a long period of time from which to develop a sequence of floating chronologies, the timing of deposition and preservation of which could be related to paleoclimatic events and conditions.

Comments on Radiocarbon Dates from Mexico

1951 ◽  
Vol 8 ◽  
pp. 33-36 ◽  
Author(s):  
Helmut de Terra
Keyword(s):  
Glacial Lake ◽  
Radiocarbon Dates ◽  
Early Archaic ◽  
Basin Of Mexico ◽  
Monte Alban ◽  
Time Sequences ◽  
Age Estimates

In the Summer of 1949, I was asked to 1 cooperate in securing appropriate samples from important Mexican sites. These, I suggested, should be selected with a view of obtaining new data on three significant problems: early man and associated geologic formations, the Archaic cultures, and the monumental civilizations of Teotihuacan and Monte Alban. This choice was dictated by the prevailing chronologic uncertainties of prehistoric cultures in Mexico and by my previous geologic approaches to time sequences in the Basin of Mexico. Computations from glacial, lake and erosion phenomena had suggested that previous age estimates, notably those presented by Vaillant (1944) and other archaeologists, had been unduly conservative. This was especially evident in the case of the basic pottery levels, known as the early Archaic or early Middle cultures, then assumed to have existed about 2100 to 1600 years ago.

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