Holocene sea levels, paleoceanography, and late glacial ice configuration near the Northumberland Strait, Maritime Provinces: Reply

1988 ◽  
Vol 25 (2) ◽  
pp. 350-351 ◽  
Author(s):  
D. B. Scott ◽  
F. S. Medioli
Keyword(s):  
Late Glacial ◽  
Maritime Provinces ◽  
Glacial Ice ◽  
Sea Levels

Holocene sea levels, paleoceanography, and late glacial ice configuration near the Northumberland Strait, Maritime Provinces

1987 ◽  
Vol 24 (4) ◽  
pp. 668-675 ◽  
Author(s):  
David B. Scott ◽  
Franco S. Medioli ◽  
Ann A. L. Miller
Keyword(s):  
Sea Level ◽  
Atlantic Coast ◽  
Late Glacial ◽  
Bay Of Fundy ◽  
Maritime Provinces ◽  
Glacial Ice ◽  
Sea Levels ◽  
Ice Caps ◽  
Present Rate ◽  
Nova Scotian

Work on new cores from old core sites in Baie Verte, New Brunswick, led to the identification of submerged salt-marsh peats, reported earlier as freshwater ones. A comprehensive sea-level curve, between 9 and 15 m below present, is based on marsh foraminiferal assemblages. These data indicate that between 4500 and 5400 BP relative sea-level (RSL) rise was comparatively slow (about 10 cm/100 years); the rate increased dramatically between 4500 and 4000 BP (1 m/100 years) and decreased between 2000 and 4000 BP to its present rate of 15 cm/100 years. We suggest RSL was falling before 5400 BP and that the sequence in our deepest core is similar to some observed in the Bay of Fundy and Nova Scotian Atlantic coast where early RSL fall is documented. To account for this sea-level record and others nearby we suggest that the ice history here is complex, with three separate ice caps thinning towards this area in late glacial times.Earlier work also indicated a number of sediment sequences barren of benthonic foraminifera, suggesting a complex marine–freshwater history for the area. The study of new cores containing the same sequences indicates no barren zones but a simple transgressive sequence with a warm-water calcareous fauna followed by an agglutinated transitional estuarine foraminiferal fauna.

Late glacial ice margins and deglacial chronology for southeastern Baffin Island and Hudson Strait, eastern Canadian Arctic

1992 ◽  
Vol 29 (5) ◽  
pp. 1000-1017 ◽  
Author(s):  
Jay A. Stravers ◽  
Gifford H. Miller ◽  
Darrell S. Kaufman
Keyword(s):  
Canadian Arctic ◽  
Late Glacial ◽  
Hudson Bay ◽  
Baffin Island ◽  
Radiocarbon Dates ◽  
Glacial Ice ◽  
Sea Levels ◽  
Molluscan Fauna ◽  
Rising Sea Levels ◽  
Eastern Canadian Arctic

Radiocarbon dates from marine piston cores and from onshore raised marine stratigraphic sections in the Hudson Strait region were used to reconstruct deglacial isochrons for 9900, 9500, 8800–8500, and 8000 BP. At the culmination of the Gold Cove readvance (9900 BP), Labrador–Ungava ice flowed northeastward across Hudson Strait and outer Frobisher Bay and stood for the last time on the Baffin Island continental shelf. Subsequent retreat by calving was rapid and profound, opening the entire Hudson Strait marine trough by 9500 BP. At this time, ice dispersal from Foxe Basin, Labrador–Ungava, and local ice on Meta Incognita Peninsula supported tidewater margins along much of the coastline, with the exception of northernmost Ungava Peninsula, where the ice margin stabilized onshore. This onshore margin remained in place throughout the Cockburn Substage while a major northeastward readvance of Ungava Bay ice (the Noble Inlet readvance from 8800 to 8500 BP) crossed outer Hudson Strait, grounding on the Hudson Strait sill and the south coast of Meta Incognita Peninsula. Sedimentation continued in an enclosed basin in western Hudson Strait, but marine circulation was prohibited by the ice dam, and upper water column salinities became too low to support a marine molluscan fauna. Ungava Bay ice was not thick enough to sustain flow across eastern Hudson Strait, and rising sea levels soon destroyed the Noble Inlet ice dam. By 8300 BP normal marine waters were circulating in eastern Hudson Strait, followed shortly thereafter (at 8100 BP) by the deglaciation of western Hudson Strait and Hudson Bay.

scholarly journals Bodengeographische Beobachtungen zur pleistozänen und holozänen Vergletscherung des Westlichen Tienshan (Usbekistan)

1996 ◽  
Vol 46 (1) ◽  
pp. 144-151
Author(s):  
Wolfgang Zech ◽  
Rupert Bäumler ◽  
Oksana Savoskul ◽  
Anatoli Ni ◽  
Maxim Petrov
Keyword(s):  
Little Ice Age ◽  
Late Glacial ◽  
Ice Age ◽  
Lower Side ◽  
Glacial Ice ◽  
Middle Holocene ◽  
Glacial Origin ◽  
Weathered Soils ◽  
Recent Origin ◽  
The Alps

Abstract. Soil geographic studies were carried out in the Oigaing valley between Ugamsky and Pskemsky range NE of Tashkent (W-Tienshan, Republic of Uzbekistan) with special regard to the Pleistocene and Holocene glaciation. Clear end moraines of the last main glaciation are preserved at the junction of Maidan and Oigaing river at 1500-1600 m a.s.l. They show intensively weathered soils with a depth of more than 80 cm. Similar deposits ol presumably Pleistocene or late glacial origin are also located upvalley at the embouchure of numerous side valleys (Beschtor, Tekesch, Aütor) into the main valley of Oigaing. All side valleys are characterized by late glacial ground and end moraines in 2500-2700 m a.s.l. showing intensively weathered brown colored soils of 30-40 cm depth. Further moraines of Holocene or recent origin are located approach of the recent glaciers which descend to 3000-3200 m. They show shallow, initial soils, and presumably correspond with glacial advances during the so-called "Little Ice Age" with a maximum advance at about 1850 in the Alps, and in the middle Holocene at about 2000 or 4000 a BP. Highly weathered, and rubefied interglacial soils developed from old Quaternary gravel are preserved above high glacial ice marginal grounds of the last main glaciation (>2850 m a.s.l.) in the lower side valley of the Barkrak river. In the upper valley huge drift could be shown above the ice marginal grounds, but without typical forms of morainic deposits. They give evidence for older glaciations with a greater extent compared with the last main glaciation. However, no corresponding moraines are present in the working area.

Past Sea Levels, Eustasy and Deformation of the Earth

1972 ◽  
Vol 2 (1) ◽  
pp. 1-14 ◽  
Author(s):  
R. I. Walcott
Keyword(s):  
Sea Level ◽  
Late Glacial ◽  
The United States ◽  
Ground Subsidence ◽  
Postglacial Rebound ◽  
Vertical Movements ◽  
Sea Levels ◽  
Atlantic Seaboard ◽  
The Earth ◽  
Change In Mean

Vertical movements of the earth's surface related to postglacial rebound, the eustatic rise in sea level and the elastic deformation of the globe due to melting of late glacial ice sheets are calculated for simplified models of the earth. The movements of the ground are large and require a reevaluation of what is meant by eustatic sea level change. This is defined here as an ocean-wide average change in mean sea level and its measurement requires widely distributed observations weighted according to the areas of oceans they represent. Evidence of a postglacial (6000-0 years BP) relative rise in sea level comes largely from regions affected by ground subsidence related to adjacent upward postglacial rebound movements in deglaciated areas: evidence for a relative fall of sea level comes from coastlines well removed from areas of rebound and which have been affected by a rise of the continental areas through compensation for the eustatic load. It is concluded: (1) no substantial eustatic change of sea level in the past 6,000 years is required to explain postglacial sea levels: (2) in late glacial time the eustatic curve is probably more like the sea level curve of Texas and Mexico than that of the Atlantic seaboard of the United States: (3) that the information of past sea levels, when sufficiently widespread, can provide an important method of studying the deep mechanical structure of the earth.

A discussion concerning the floor of the northwest Indian Ocean - Marine sediments and bottom communities of the Seychelles

1966 ◽  
Vol 259 (1099) ◽  
pp. 279-290 ◽  
Keyword(s):  
Sedimentary Facies ◽  
Close Relation ◽  
Late Glacial ◽  
Carbonate Sediments ◽  
Sea Levels ◽  
Bottom Communities ◽  
Water Region ◽  
Detrital Carbonate ◽  
Intertidal Pools ◽  
Coral Islands

The shoal water region of the Seychelles Bank, covering about 31000 km 2 , is floored by relatively thin detrital carbonate sediments. Around the granitic and coral islands at least four submarine platforms can be recognized and are tentatively related to Late-glacial and Postglacial sea levels. A shallow discontinuous rim is developed around the margin of the Bank. The sediments and bottom communities of the open Bank and of the reef flats are described in terms of nine principal environments. Sedimentary facies are distinguished by the proportions of different organic constituents, by variations in grain size and by presence or absence of quartz. Syngenetic pyrite and collophane occur locally as minor constituents. Away from the reef flats the Bank supports a fairly uniform bottom community, the main elements being mollusca and foraminifera. The reefs may be considered as large intertidal pools with many microenvironments and with a complex zonation of communities showing rapid lateral changes in composition. There is a close relation between the sedimentary facies of the reefs and the distribution of the bottom communities.

Geomorphic Evidence for Late Glacial Ice Dynamics on Southern Baffin Island and in Outer Hudson Strait, Nunavut, Canada

2001 ◽  
Vol 33 (3) ◽  
pp. 249 ◽  
Author(s):  
Johan Kleman ◽  
David Marchant ◽  
Ingmar Borgstrom
Keyword(s):  
Late Glacial ◽  
Baffin Island ◽  
Ice Dynamics ◽  
Glacial Ice

Late Pleistocene Glaciations in the Northwestern Sierra Nevada, California

2002 ◽  
Vol 57 (3) ◽  
pp. 409-419 ◽  
Author(s):  
L. Allan James ◽  
Jon Harbor ◽  
Derek Fabel ◽  
Dennis Dahms ◽  
David Elmore
Keyword(s):  
Sierra Nevada ◽  
Late Glacial ◽  
Lateral Moraine ◽  
Riparian Ecosystems ◽  
Glacial Ice ◽  
Central California ◽  
Minimum Age ◽  
History Of ◽  
Ice Retreat ◽  
Moraine Ridge

AbstractPleistocene fluvial landforms and riparian ecosystems in central California responded to climate changes in the Sierra Nevada, yet the glacial history of the western Sierra remains largely unknown. Three glacial stages in the northwestern Sierra Nevada are documented by field mapping and cosmogenic radionuclide surface-exposure (CRSE) ages. Two CRSE ages of erratic boulders on an isolated till above Bear Valley provide a limiting minimum age of 76,400±3800 10Be yr. Another boulder age provides a limiting minimum age of 48,800±3200 10Be yr for a broad-crested moraine ridge within Bear Valley. Three CRSE ages producing an average age of 18,600±1180 yr were drawn from two boulders near a sharp-crested bouldery lateral moraine that represents an extensive Tioga glaciation in Bear Valley. Nine CRSE ages from striated bedrock along a steep valley transect average 14,100±1500 yr and suggest rapid late-glacial ice retreat from lower Fordyce Canyon with no subsequent extensive glaciations. These ages are generally consistent with glacial and pluvial records in east-central California and Nevada.

scholarly journals Seismostratigraphy of the Middle St. Lawrence Esturary: A Late Quaternary Glacial Marine to Estuarine Depositional/Erosional Record

2007 ◽  
Vol 46 (2) ◽  
pp. 133-150 ◽  
Author(s):  
Dan Praeg ◽  
Bruno d’Anglejan ◽  
James P. M. Syvitski
Keyword(s):  
Late Quaternary ◽  
Coarse Grained ◽  
Glacial Ice ◽  
Sea Levels ◽  
The North ◽  
Deep Waters ◽  
Saguenay Fjord ◽  
Mass Displacement ◽  
Unconformity Surface ◽  
Middle Estuary

ABSTRACTA buried bedrock trough 350 m deep extends 100 km above Saguenay Fjord beneath the North Channel of the middle estuary. Four of five regional seismostratigraphic units are recognized in and adjacent to the trough; unit 1 (glacial ice-contact) and older sediments might also be present beneath the largely unpenetrated trough axis. Units 2 and 3 represent thick glacial marine sediments deposited in the >550 m deep waters of the Goldthwait Sea after glacial withdrawal ca. 13 ka BP: lower draped muds 10-20 m thick (unit 2) suggest deposition proximal to a retreating ice margin, while upper onlapping muds > 290 m thick (unit 3) record distal basin-filling; lateral transition to a coarse-grained proximal wedge 5*260 m thick (unit 2) is indicated by unit 3 reflectors rising and strengthening towards the Saguenay entrance, where a stable ice-margin ca. 13-11 ka BP supplied sediment to the lower and middle estuary. Unit 4 corresponds to lobes over 30 m thick on both sides of the upper North Channel, recording marginal input from glacial fluvio-deltaic sources. Unit 5 (estuarine sands, gravels and muds =£30 m thick) unconformably overlies glacial units. A smooth unconformity surface records erosion (at least 15 m, to axial depths >150m) by strong currents; irregular relief above depths of 25-50 m might relate to relative sea levels below present ca. 7-6 ka BP. Sand bedforms (apparently inactive) occur at the estuary floor, and possibly buried beneath estuarine muds; buried bedforms would imply an early Holocene genesis. Greatest thicknesses of estuarine mud coincide with adjacent fluvial discharges. Sandy/gravelly veneers form the estuary floor in most places. Mass displacement has disturbed units 3 and 5 along the northern, and locally southern, walls of the North Channel.

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