Relict iceberg furrows on the Laurentian Channel and western Grand Banks

1976 ◽  
Vol 13 (8) ◽  
pp. 1082-1092 ◽  
Author(s):  
Lewis H. King
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Northwest Atlantic ◽  
Offshore Area ◽  
Side Scan Sonar ◽  
Grand Banks ◽  
Level Curves ◽  
History Of

A side-scan sonar survey along the western bank of the Laurentian Channel and on the western Grand Banks revealed the occurrence of iceberg furrows that are probably of Late Pleistocene age. The occurrence of furrows in the Gulf of St. Lawrence is significant in that it helps to date iceberg furrows along the northeast Newfoundland–Labrador margin of the northwest Atlantic, provides data on the history of deglaciation of the offshore area of the Atlantic Provinces, provides a means of evaluating sea level curves, and provides additional evidence for the broad regional extent of the Late Pleistocene shoreline at 115 to 120 m.

Mid-Cretaceous onlap history of the Market Weighton structural high, northeast England

1999 ◽  
Vol 136 (6) ◽  
pp. 681-696 ◽  
Author(s):  
C. J. UNDERWOOD ◽  
S. F. MITCHELL
Keyword(s):  
Sea Level ◽  
High Frequency ◽  
Sedimentary Facies ◽  
Relative Sea Level ◽  
Western Margin ◽  
Level Curves ◽  
History Of ◽  
Tectonic Settings ◽  
Global Sea Level ◽  
Structural High

The mid-Cretaceous sediments of northeast England were deposited at the western margin of the southern North Sea Basin, with sedimentation occurring in a range of tectonic settings. Detailed analysis of the areal distribution and sedimentary facies of Aptian to earliest Cenomanian sediments has allowed the pattern of onlap onto the Market Weighton structural high and changes in relative sea level to be documented. Successive onlap episodes during the Early Aptian, Late Aptian and Early Albian culminated in the final flooding of the structure during the Late Albian (varicosum Subzone). Sea-level curves generated from coastal onlap patterns are difficult to relate to published ‘global’ sea-level curves due to the high frequency of the fluctuations in relative sea level observed. Despite this, detailed correlation and analysis of sedimentological events suggest that even the most expanded, basinal succession is relatively incomplete. This study has also shown that the change from dominantly syn-tectonic to dominantly post-tectonic sedimentation style occurred in the late Early Albian.

Variations of fluvial patterns and infilling history of a paleoincised valley system during Late Pleistocene to Holocene, Offshore Pahang River, Peninsular Malaysia

2018 ◽  
Vol 6 (1) ◽  
pp. T39-T50
Author(s):  
Md Mostafizur Rahman ◽  
Edlic Sathiamurthy ◽  
Guangfa Zhong ◽  
Jianghua Geng ◽  
Zhifei Liu
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Peninsular Malaysia ◽  
Glacial Cycle ◽  
Shallow Marine ◽  
3D Data ◽  
Data Volume ◽  
History Of ◽  
Late Pleistocene To Holocene ◽  
Cover Thickness

High-resolution 2D acoustic profiles, combined with time slices from a 3D data volume, were used to investigate the paleoincised valleys offshore of the present-day Pahang River, South China Sea. Paleovalleys were formed during the regressive phase of the last glacial cycle. They were submerged and possibly filled during valley formation and postglacial marine transgression. Interpretation of acoustic profiles illustrates that the valleys were incised and infilled during the regression and low stand followed by subsequent deglacial sea-level rise. They were overlain by a transgressive ravinement surface suggesting transitional deposits between fluvial-dominated filling and shallow-marine deposition. This ravinement surface is overlain by Holocene shallow marine deposits. A low-sinuosity low-stand valley system changed to a high-sinuosity meander belt and eventually evolved into a deltaic distributary channel system before the complete submergence of the area. The average Late Pleistocene surface lies between 53 and 64 m below present-day mean sea level in the study area with approximately 16–50 m of valley incision. The Holocene shallow marine cover thickness varies from 5 to 10 m.

Isostatic adjustments in a full glacial sea

1983 ◽  
Vol 20 (6) ◽  
pp. 895-917 ◽  
Author(s):  
John England
Keyword(s):  
Sea Level ◽  
Ellesmere Island ◽  
Relative Sea Level ◽  
Level Curves ◽  
Last Glaciation ◽  
Isostatic Equilibrium ◽  
Paleoclimatic Changes ◽  
History Of ◽  
Rapid Emergence

During the last glaciation an ice-free corridor existed between the northeast Ellesmere Island and northwest Greenland ice sheets. This corridor constituted a peripheral depression in which the marine limit marks the uppermost extent of a full glacial sea. The full glacial sea is characterized by (1) 14C dates on in situ marine shells that predate initial emergence (unloading) followed by (2) synchronous emergence from the marine limit throughout the peripheral depression. Relative sea-level curves from the full glacial sea confirm previous morphostratigraphic and glacioisostatic evidence for limited ice extent during the last glaciation. These curves also document the history of glacial unloading and the form of the relative sea-level curve that one would theoretically expect in the peripheral depression. The form of the curves presented here is unlike any other published emergence curves from arctic Canada or from Fennoscandia.The relative sea-level curves for northeast Ellesmere Island show three segments: (1) an interval of stable relative sea level (isostatic equilibrium) at the marine limit between at least 11 000 and 8000 BP; (2) an interval of slow emergence from 8000 to 6200 BP during which northeast Ellesmere Island ice slowly retreated; and (3) an interval of rapid emergence, caused by rapid glacial unloading, after 6200 BP when a prominent amelioration was in progress. These relative sea-level curves are discussed in relation to other paleoclimatic changes and the deglacial history of northwest Greenland. These curves are of regional importance in that they provide a new means of distinguishing between areas that were ice covered and ice free during the last glaciation.

Late Pleistocene and Holocene melting history of the Antarctic ice sheet derived from sea-level variations

2000 ◽  
Vol 167 (1-2) ◽  
pp. 85-103 ◽  
Author(s):  
M. Nakada ◽  
R. Kimura ◽  
J. Okuno ◽  
K. Moriwaki ◽  
H. Miura ◽  
...  
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Ice Sheet ◽  
Antarctic Ice Sheet ◽  
History Of ◽  
Sea Level Variations ◽  
The Antarctic

scholarly journals Late Pleistocene sea-level changes recorded in tidal and fluvial deposits from Itaubal Formation, onshore portion of the Foz do Amazonas Basin, Brazil

2015 ◽  
Vol 45 (suppl 1) ◽  
pp. 63-78 ◽  
Author(s):  
Isaac Salém Alves Azevedo Bezerra ◽  
Afonso César Rodrigues Nogueira ◽  
José Tasso Felix Guimarães ◽  
Werner Truckenbrodt
Keyword(s):  
Sea Level ◽  
Late Pleistocene ◽  
Sea Level Changes ◽  
Fluvial Deposits ◽  
Base Level ◽  
Lower Unit ◽  
Basement Rocks ◽  
History Of ◽  
Floodplain Deposits ◽  
The Last Glacial

ABSTRACTThe Pleistocene deposits exposed in the Amapá Coastal Plain (onshore portion of the Foz do Amazonas Basin, northeastern South America) were previously interpreted as Miocene in age. In this work, they were named as "Itaubal Formation" and were included in the quaternary coastal history of Amazonia. The study, through facies and stratigraphic analyses in combination with optically stimulated luminescence (single and multiple aliquot regeneration), allowed interpreting this unit as Late Pleistocene tidal and fluvial deposits. The Itaubal Formation, which unconformably overlies strongly weathered basement rocks of the Guianas Shield, was subdivided into two progradational units, separated by an unconformity related to sea-level fall, here named as Lower and Upper Units. The Lower Unit yielded ages between 120,600 (± 12,000) and 70,850 (± 6,700) years BP and consists of subtidal flat, tide-influenced meandering stream and floodplain deposits, during highstand conditions. The Upper Unit spans between 69,150 (± 7,200) and 58,150 (± 6,800) years BP and is characterized by braided fluvial deposits incised in the Lower Unit, related to base-level fall; lowstand conditions remained until 23,500 (± 3,000) years BP. The studied region was likely exposed during the Last Glacial Maximum and then during Holocene, covered by tidal deposits influenced by the Amazon River.

Sea level change in the Holocene on the northern Great Barrier Reef

1978 ◽  
Vol 291 (1378) ◽  
pp. 167-186 ◽  
Keyword(s):  
Great Barrier Reef ◽  
Sea Level ◽  
Radiometric Dating ◽  
Barrier Reef ◽  
Sea Levels ◽  
Level Curves ◽  
Level Change ◽  
Fossil Corals ◽  
History Of ◽  
Degree Of Confidence

Detailed studies, utilizing a range of both well controlled sea level criteria and dates, are required if Holocene time-sea level curves are to be established with any degree of confidence. This paper is restricted to an interpretation of Expedition results from the northern Great Barrier Reef, excluding those from the drill core. Extensive colonies of emergent fossil corals in growth position indicate that present sea level was first reached about 6000 a b. p. Elevations of cay surfaces, cemented rubble platforms, microatolls, coral shingle ridges, reef flats and mangrove swamps, referenced to present sea level show an array of heights. However, levels of particular features are accordant on many reefs: it is believed that these can be related to particular sea levels. Radiometric dating provides the time framework. Ages of samples from similar deposits on different reefs are surprisingly consistent. Oscillations in sea level since 6000 a b.p ., relative to present sea level, are identified with varying degrees of confidence. This history of relative sea level does not separate eustatic from noneustatic components.

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