Late Quaternary paleoclimatology and paleooceanography of the Labrador Sea and Baffin Bay: an alternative viewpoint

A stratigraphic framework for eastern Labrador Sea cores has been developed for the interval 0–90 000 years BP through analysis of oxygen isotopes, volcanic ash, benthonic foraminifera, and the radiolarian Diplocyclas davisiana. Benthonic and planktonic foraminiferal isotope stratigraphy and the time scale of Shackleton and Opdyke provide a basis for the approximate dating of a series of marker events which include ash zones at ca. 59 000 and ≤ 21 000 years BP; benthonic foraminiferal abundance maxima at ca. 83 000, 75 000, 60 000, 19 000, and 3000 years BP; and D. davisiana percentage maxima at ca. 90 000, 73 000, 64 000, 54 000, 45 000 – 32 000, and 10 000 years BP. Incursions of subpolar planktonic foraminifera into the area during parts of isotopic stage 2 (between about 13 000 and 25 000 years BP but probably excluding the 15 000–18 000 years BP glacial maximum interval) and during the isotopic stage 4/5a transition (around 75 000 years BP) suggest that the eastern Labrador Sea was free of sea ice, at least in summer during periods of rapid continental ice sheet growth which lead to the isotopic stage 4 and stage 2 glacial maxima. A larger than normal stage 1/stage 2 difference in the isotopic composition of benthonic foraminifera (1.8‰) implies that this open water and attendant surface cooling was a potential source for colder than modern deep water. In contrast the Norwegian Sea was a reservoir of warmer than modern deep water during the last glacial.

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Progress report on low-level Aeromagnetic profiles over the Labrador Sea, Baffin Bay, and across the North Atlantic Ocean

10.4095/103341 ◽

1967 ◽

Cited By ~ 2

Author(s):

P J Hood ◽

P Sawatzky ◽

M E Bower

Keyword(s):

Atlantic Ocean ◽

North Atlantic ◽

North Atlantic Ocean ◽

Progress Report ◽

Labrador Sea ◽

Baffin Bay ◽

Low Level ◽

The North ◽

The North Atlantic

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Late Quaternary sporadic development of Desmophyllum dianthus deep-coral populations in the southern Labrador Sea with specific attention to their 14C- and 230Th-dating

Marine Chemistry ◽

10.1016/j.marchem.2020.103807 ◽

2020 ◽

Vol 224 ◽

pp. 103807

Author(s):

Jenny Maccali ◽

Claude Hillaire-Marcel ◽

Lucie Ménabréaz ◽

Bassam Ghaleb ◽

Aurélien Blénet ◽

...

Keyword(s):

Late Quaternary ◽

Labrador Sea ◽

Desmophyllum Dianthus ◽

Deep Coral

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The Labrador Sea during the late Quaternary: Introduction

Canadian Journal of Earth Sciences ◽

10.1139/e94-001 ◽

1994 ◽

Vol 31 (1) ◽

pp. 1-4 ◽

Cited By ~ 6

Author(s):

Claude Hillaire-Marcel ◽

Anne de Vernal ◽

Marc Lucotte ◽

Alfonso Mucci

Keyword(s):

Late Quaternary ◽

Labrador Sea

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Full-fit reconstruction of the Labrador Sea and Baffin Bay

Solid Earth Discussions ◽

10.5194/sed-5-917-2013 ◽

2013 ◽

Vol 5 (2) ◽

pp. 917-962 ◽

Cited By ~ 5

Author(s):

M. Hosseinpour ◽

R. D. Müller ◽

S. E. Williams ◽

J. M. Whittaker

Keyword(s):

North America ◽

Continental Crust ◽

Seafloor Spreading ◽

Labrador Sea ◽

Gravity Inversion ◽

Seismic Profiles ◽

Baffin Bay ◽

Davis Strait ◽

Break Up ◽

Magnetic Lineations

Abstract. Reconstructing the opening of the Labrador Sea and Baffin Bay between Greenland and North America remains controversial. Recent seismic data suggest that magnetic lineations along the margins of the Labrador Sea, originally interpreted as seafloor spreading anomalies, may lie within the crust of the continent–ocean transition. These data also suggest a more seaward extent of continental crust within the Greenland margin near the Davis Strait than assumed in previous full-fit reconstructions. Our study focuses on reconstructing the full-fit configuration of Greenland and North America using an approach that considers continental deformation in a quantitative manner. We use gravity inversion to map crustal thickness across the conjugate margins, and assimilate observations from available seismic profiles and potential field data to constrain the likely extent of different crustal types. We derive end-member continental margin restorations following alternative interpretations of published seismic profiles. The boundaries between continental and oceanic crust (COB) are restored to their pre-stretching locations along small circle motion paths across the region of Cretaceous extension. Restored COBs are fitted quantitatively to compute alternative total-fit reconstructions. A preferred full-fit model is chosen based on the strongest compatibility with geological and geophysical data. Our preferred model suggests that (i) the COB lies oceanward of magnetic lineations interpreted as magnetic anomaly 31 (70 Ma) in the Labrador Sea, (ii) all previously identified magnetic lineations landward of anomaly 27 reflect intrusions into continental crust, and (iii) the Ungava fault zone in Davis Strait acted as a leaky transform fault during rifting. This robust plate reconstruction reduces gaps and overlaps in the Davis Strait and suggests that there is no need for alternative models proposed for reconstructions of this area including additional plate boundaries in North America or Greenland. Our favored model implies that break up and formation of continent–ocean transition (COT) first started in the southern Labrador Sea and Davis Strait around 88 Ma and then propagated north and southwards up to onset of real seafloor spreading at 63 Ma in the Labrador Sea. In the Baffin Bay, continental stretching lasted longer and actual break up and seafloor spreading started around 61 Ma (Chron 26).

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Late Quaternary sedimentation in Baffin Bay

Canadian Journal of Earth Sciences ◽

10.1139/e87-174 ◽

1987 ◽

Vol 24 (9) ◽

pp. 1833-1846 ◽

Cited By ~ 51

Author(s):

A. E. Aksu ◽

David J. W. Piper

Keyword(s):

Debris Flow ◽

Late Quaternary ◽

Ocean Basin ◽

The Arctic ◽

Bottom Current ◽

Eastern Canada ◽

Baffin Bay ◽

Quaternary Glaciation ◽

Continental Slopes ◽

Channel Systems

Baffin Bay is a small ocean basin that connects the Arctic and Atlantic oceans. The adjacent continental shelves have been extensively reworked during Quaternary glaciation. The shelf break generally lies between 200 and 500 m. The continental slope passes directly into the abyssal plain of Baffin Bay basin without any major submarine canyon – deep-sea fan system being present, except for a large smooth sediment apron in northern Baffin Bay.On the basis of over 50 piston cores, six Quaternary sediment facies are distinguished from detrital mineralogy (reflected in colour) and sediment texture. Facies A, B, and C are predominantly ice-rafted or are debris flow deposits, each with a distinct mineralogy. Facies D is turbidites and bottom-current sorted sands, silts, and muds. Facies E is hemipelagic sediment. Facies F consists of sediments ranging from slumps, through debris flow deposits, to fine-grained turbidites, with a distinctive provenance in northern Baffin Bay.These sediment facies appear to be partly controlled by glacial conditions. Hemipelagic facies E predominates during the present interglacial. During glacial stages, facies D turbidites were deposited. They resulted from slumping of proglacial sediments on the continental slopes off Greenland and Baffin Island. Facies C and F occurred on the continental slopes at these times. Ice-rafted facies A and B predominate at several horizons, reflecting a rapid breakup of ice shelves in northern Baffin Bay and increased rates of iceberg melting within the Bay. Overall sedimentation rates are relatively low, reflecting dry-base ice sheets in source areas.Deep-sea channel systems floored by sorted coarse sediments and bounded by muddy levees are absent in Baffin Bay, in contrast to mid-latitude glaciated continental margins off eastern Canada. These channel systems are the result of melting of wet-base glaciers, which provide a localized supply of sediment that is sorted by ice margin processes. In Baffin Bay, most glacial sediments are derived by calving of icebergs, probably from dry-base glaciers. Sediments are gradually released over large areas as the bergs melt, and are subsequently redistributed by debris flows.

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