scholarly journals Vertebra of a Bowhead whale (Balaena mysticetus) in Late Wisconsinan deglacial marine sediments, Trout River, Newfoundland, and local late-glacial sea-level change

2010 ◽  
Vol 61 (2-3) ◽  
pp. 225-227
Author(s):  
Ian A. Brookes
Keyword(s):  
Sea Level ◽  
Marine Sediments ◽  
Sea Level Change ◽  
Late Glacial ◽  
Bowhead Whale ◽  
Balaena Mysticetus ◽  
Level Change ◽  
Late Wisconsinan

Abstract This note reports the geological contexts and radiocarbon and calibrated ages of whalebone and bivalve recovered from emerged deglacial marine sediments at Trout River, Newfoundland (49°28.6’ N, 58°07’ W). The rate of sea-level fall is calculated for the first deglacial millennium, and discrepancies are noted between calibrated ages of bone and shell.

A comparison of observed and theoretical postglacial relative sea level in Atlantic Canada

1981 ◽  
Vol 18 (7) ◽  
pp. 1146-1163 ◽  
Author(s):  
Garry Quinlan ◽  
Christopher Beaumont
Keyword(s):  
Sea Level ◽  
Field Data ◽  
Sea Level Change ◽  
Atlantic Canada ◽  
Relative Sea Level ◽  
Level Curves ◽  
Level Change ◽  
The Common ◽  
Late Wisconsinan ◽  
Outermost Zone

Two extreme models of late Wisconsinan ice cover in Atlantic Canada and the northeastern U.S.A. are shown to produce postglacial relative sea level curves that bracket existing field observations at six sites throughout the region. This suggests that the true late Wisconsinan ice distribution is probably intermediate to the two contrasting reconstructions proposed. Both ice models predict the existence of four relative sea level zones: an innermost zone closest to the centre of glaciation in which relative sea level falls continuously throughout postglacial time; an outermost zone in which it rises continuously; and two transitional zones in which it first falls and then rises in varying proportions according to the distance from the ice margin. The distinctive forms of the relative sea level curves are probably representative of each of the zones and are unlikely to be significantly perturbed even by large local ice readvances. They, therefore, establish patterns with which future field data are expected to conform. The form that the geological record of relative sea level change is likely to take within each zone is discussed and promising settings for the collection of new data are proposed. The common practice of separating relative sea level into an isostatic and a eustatic component is analysed and shown to be incorrect as usually applied. The practice is also shown to be unnecessary because the models discussed in this paper predict changes in relative sea level that can be compared directly with the observations.

scholarly journals Late Glacial to Holocene relative sea-level change in Assynt, northwest Scotland, UK

2015 ◽  
Vol 84 (2) ◽  
pp. 214-222 ◽  
Author(s):  
Christine A. Hamilton ◽  
Jeremy M. Lloyd ◽  
Natasha L.M. Barlow ◽  
James B. Innes ◽  
Rachel Flecker ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
Sea Level Change ◽  
Late Glacial ◽  
Test Model ◽  
Relative Sea Level ◽  
Level Change ◽  
Isostatic Adjustment ◽  
Global And Local ◽  
First Time

Relative sea-level change (RSL), from the Late Glacial through to the late Holocene, is reconstructed for the Assynt region, northwest Scotland, based on bio- and lithostratigraphical analysis. Four new radiocarbon-dated sea-level index points help constrain RSL change for the Late Glacial to the late Holocene. These new data, in addition to published material, capture the RSL fall during the Late Glacial and the rise and fall associated with the mid-Holocene highstand. Two of these index points constrain the Late Glacial RSL history in Assynt for the first time, reconstructing RSL falling from 2.47 ± 0.59 m OD to 0.15 ± 0.59 m OD at c. 14,000–15,000 cal yr BP. These new data test model predictions of glacial isostatic adjustment (GIA), particularly during the early deglacial period which is currently poorly constrained throughout the British Isles. Whilst the empirical data from the mid- to late-Holocene to present matches quite well with the recent GIA model output, there is a relatively poor fit between the timing of the Late Glacial RSL fall and early Holocene RSL rise. This mismatch, also evident elsewhere in northwest Scotland, may result from uncertainties associated with both the global and local ice components of GIA models.

SEA LEVEL CHANGES IN THE NEOGENE OF SOUTHERN VICTORIA

1978 ◽  
Vol 18 (1) ◽  
pp. 64 ◽  
Author(s):  
C. W. Mallett
Keyword(s):  
Grain Size ◽  
Sea Level ◽  
Marine Sediments ◽  
Late Miocene ◽  
Sea Level Change ◽  
Early Miocene ◽  
Sea Level Changes ◽  
Sea Levels ◽  
Level Change ◽  
Gippsland Basin

The distribution and lithology of marine sediments in southern Victoria are related to climatic events and the associated sea level changes. The most extensive transgression on the northern (onshore) margin of the southern Victorian Tertiary basins occurred late in the Early Miocene, with widespread deposition of calcareous muds and localised calcarenites with Lepidocvclina. Shallowing at approximately 14 m.y. affected all southern Victoria, initiating lithological changes in the Otway and Port Phillip Basins, and coinciding with erosion in the Gippsland Basin. Throughout the Late Miocene the grain size of sediments tended to increase and cross-bedded calcarenites became more common, consistent with shallowing deposition and sea withdrawal. By approximately 6 m.y., near the end of the Late Miocene, the sea had completely withdrawn from the onshore areas of southern Victoria.Pliocene and Pleistocene outcrops are scattered and thin, and marine beds are exclusively of nearshore and shallow deposition. For much of this period sea level was lower than at present. High levels in the Pliocene are indicated at approximately 5 m.y. and 3.5 m.y. High sea levels, associated with the rapid alternation of glacial and interglacial periods which typify the Pleistocene Epoch, were initiated late in the Pliocene, close to 2 m.y.Changes to the planktonic foraminiferal faunas parallel the sedimentological responses to sea level change. These suggest that palaeoclimatic events were the main controlling factor in Neogene sea level changes in southern Victoria, and allow differentiation of the eustatic and tectonic controls on sedimentation.

Radiocarbon Ages from Two Submerged Strandline Features in the Western Gulf of Maine and a Sea-Level Curve for the Northeastern Massachusetts Coastal Region

1993 ◽  
Vol 40 (1) ◽  
pp. 38-45 ◽  
Author(s):  
Robert N. Oldale ◽  
Steven M. Colman ◽  
Glen A. Jones
Keyword(s):  
Sea Level ◽  
Gulf Of Maine ◽  
Coastal Region ◽  
Sea Level Change ◽  
Level Curve ◽  
Radiocarbon Dates ◽  
Level Change ◽  
The North ◽  
Rapid Changes ◽  
Late Wisconsinan

AbstractNew radiocarbon dates provide ages for two submerged strandline features on the Massachusetts inner shelf. These ages provide limited control on a relative sea-level (RSL) curve for the late Wisconsinan and Holocene. The curve indicates a late Wisconsinan high stand of RSL of +33 m about 14,000 yr ago and a very short-lived relative low stand of about -43 m at about 12,000 yr ago followed by a rise to present sea level. Rapid changes of RSL around 12,000 yr ago may be related to changes in global glacial meltwater discharge and eustatic sea-level change shown by dated corals off Barbados. Variations in the magnitude and timing of RSL change from south to north along the coast of the western Gulf of Maine are due to greater crustal depression and later deglaciation to the north.

Delayed Postglacial Uplift and Synglacial Sea Levels in Coastal Central New England

1993 ◽  
Vol 40 (1) ◽  
pp. 46-54 ◽  
Author(s):  
Carl Koteff ◽  
Gilpin R. Robinson ◽  
Richard Goldsmith ◽  
Woodrow B. Thompson
Keyword(s):  
New England ◽  
Sea Level ◽  
Sea Level Change ◽  
Sea Levels ◽  
Flat Surfaces ◽  
Level Change ◽  
Base Level ◽  
Elevation Data ◽  
Ice Retreat ◽  
Late Wisconsinan

AbstractThe postglacial uplift pattern indicated by elevations of ice-marginal glaciomarine deltas in coastal New England, deposited between approximately 15,000 and 14,000 yr B.P. during ice retreat from northeastern Massachusetts into southwestern Maine, is very similar to that previously recorded for glaciolacustrine deltas of similar age from inland areas of New England. Multiple regression analyses of elevations from both sets of deltas show an extremely close fit to tilted flat surfaces that rise 0.852 m/km to the N 28.5°W along the coast and 0.889 m/km to the N 20.5°W in western New England. The close similarity of uplift pattern in areas where elevation data are from different base-level media, along with additional shore-line evidence, indicates (1) that both areas are part of the same crustal postglacial uplift block, (2) that postglacial uplift was delayed until after 14,000 yr B.P., and (3) that little or no eustatic sea-level change occurred between 15,000 and 14,000 yr B.P., during which time the margin of the late Wisconsinan Laurentide ice sheet retreated about 100 km from Boston, Massachusetts, into southwestern Maine. Elevation data from even younger glaciomarine deltas in the coastal area indicate that soon after the ice margin reached southwestern Maine and adjacent New Hampshire (ca, 14,000 yr B.P.), eustatic sea level rose rapidly 7-10 m during the time that the ice margin retreated 5-10 km, which may have occurred during an interval of only 50-100 yr, Our new data not only confirm the delayed postglacial uplift model previously described for western New England, but also indicate that little or no eustatic sea-level change occurred during a substantial period of early deglaciation. However, at about 14,000 yr B.P., sea level rose rapidly. Postglacial uplift in the region apparently began between 14,000 and 13,300 yr B.P., before the retreating ice margin reached eastern Maine.

Phanerozoic Oxygen

2017 ◽  
Author(s):  
Donald Eugene Canfield
Keyword(s):  
Oxygen Consumption ◽  
Organic Carbon ◽  
Sea Level ◽  
Time Scale ◽  
Atmospheric Oxygen ◽  
Sea Level Change ◽  
Oxygen Production ◽  
Level Change ◽  
History Of ◽  
Geologic Processes

This chapter discusses the modeling of the history of atmospheric oxygen. The most recently deposited sediments will also be the most prone to weathering through processes like sea-level change or uplift of the land. Thus, through rapid recycling, high rates of oxygen production through the burial of organic-rich sediments will quickly lead to high rates of oxygen consumption through the exposure of these organic-rich sediments to weathering. From a modeling perspective, rapid recycling helps to dampen oxygen changes. This is important because the fluxes of oxygen through the atmosphere during organic carbon and pyrite burial, and by weathering, are huge compared to the relatively small amounts of oxygen in the atmosphere. Thus, all of the oxygen in the present atmosphere is cycled through geologic processes of oxygen liberation (organic carbon and pyrite burial) and consumption (weathering) on a time scale of about 2 to 3 million years.

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