Evolution of the Labrador Sea

1973 ◽  
Vol 10 (5) ◽  
pp. 637-644 ◽  
Author(s):  
R. D. Hyndman
Keyword(s):  
Mantle Plume ◽  
Hot Spot ◽  
Spreading Rate ◽  
Magnetic Data ◽  
Labrador Sea ◽  
The West ◽  
Davis Strait ◽  
Good Agreement

The age and spreading rate of the Labrador Sea have been computed from the basement bathymetry. The data give a time of termination of opening 48 m.y. ago and a mean spreading rate of 0.64 cm per year, in good agreement with previous estimates from magnetic data. The shallow depths in the Labrador Sea must be accounted for by assuming that the present Iceland hot spot or mantle plume was located under Davis Strait, to the west of Greenland during the opening. A model is proposed for the separation of Greenland from Europe and Canada driven by this plume.

scholarly journals Cretaceous and Cenozoic dinoflagellate cysts and other palynomorphs from the western and eastern margins of the Labrador–Baffin Seaway

2016 ◽  
Vol 36 ◽  
pp. 1-143 ◽  
Author(s):  
Robert A. Fensome ◽  
Henrik Nøhr-Hansen ◽  
Graham L. Williams
Keyword(s):  
New Combination ◽  
Labrador Sea ◽  
New Genera ◽  
The West ◽  
Palynological Analysis ◽  
Baffin Bay ◽  
Davis Strait ◽  
History Of ◽  
Greenland Margin ◽  
Plant Microfossil

New palynological analysis of samples from 13 offshore wells on the Canadian Margin and six wells on the West Greenland Margin has led to a new event biostratigraphic framework for Cretaceous–Cenozoic strata of the Labrador Sea – Davis Strait – Baffin Bay (Labrador–Baffin Seaway) region. This framework is based on about 150 dinoflagellate cyst taxa and 30 acritarch, algal, fungal and plant microfossil (mostly miospore) taxa. In the systematics we include three new genera of dinocysts (Scalenodinium, Simplicidinium and Taurodinium), 16 new species of dinocysts (Chiropteridium gilbertii, Chytroeisphaeridia hadra, Cleistosphaeridium elegantulum, Cleistosphaeridium palmatum, Dapsilidinium pseudoinsertum, Deflandrea borealis, Evittosphaerula? foraminosa, Ginginodinium? flexidentatum, Hystrichosphaeridium quadratum, Hystrichostrogylon digitus, Impletosphaeridium apodastum, Scalenodinium scalenum, Surculosphaeridium convocatum, Talladinium pellis, Taurodinium granulatum and Trithyrodinium? conservatum), four emendations of dinocyst genera (Alterbidinium, Chatangiella, Chiropteridium and Surculosphaeridium), six new combinations for dinocyst species (Alterbidinium biaperturum, Deflandrea majae, Kleithriasphaeridium mantellii, Simplicidinium insolitum, Spongodinium grossum, Spongodinium obscurum), one new acritarch species (Fromea quadrangularis), one new miospore species (Baculatisporites crenulatus) and one new combination for miospores (Tiliaepollenites crassipites). Most of the taxa included provide age information, almost exclusively last occurrences (range ‘tops’), but some are useful mainly for environmental interpretations. Collectively, they provide a powerful tool for helping to establish the geological history of the Labrador–Baffin Seaway.  

Marginal Basins of the Labrador Sea and the Davis Strait Hot Spot

1975 ◽  
Vol 12 (6) ◽  
pp. 1041-1045 ◽  
Author(s):  
R. D. Hyndman
Keyword(s):  
Hot Spot ◽  
Sedimentary Basins ◽  
Crustal Thickness ◽  
Labrador Sea ◽  
Sea Floor ◽  
Davis Strait ◽  
Basement Depth ◽  
The Difference

There are deep marginal sedimentary basins in the Labrador Sea extending to the region of Davis Strait. In contrast, the central part of the Sea shoals toward Davis Strait. The difference is explained by the central part of the Sea being formed while the Davis Strait hot spot was active, producing increased vulcanism and crustal thickness. The sea floor along the margins was produced before the hot spot became active about 60 m.y. ago, so has normal crustal thickness and thus normal basement depth.

Paralepis coregonoides borealis (Osteichthyes: Paralepididae) from Davis Strait and Labrador Sea

1971 ◽  
Vol 28 (8) ◽  
pp. 1199-1203
Author(s):  
W. H. Lear ◽  
A. W. May
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
West Coast ◽  
Labrador Sea ◽  
The West ◽  
Atlantic Salmon Salmo Salar ◽  
Davis Strait

Twenty Paralepis specimens were taken from the stomachs of 10 Atlantic salmon (Salmo salar L.) caught by drift net at seven fishing stations in the Davis Strait and Labrador Sea. Eleven of the 20 specimens were identified as Paralepis coregonoides borealis Reinhardt on the basis of vertebral counts, and the remainder are tentatively assigned to this species. These are the first records of adult specimens from the Davis Strait, though a few have been recorded from the west coast of Greenland.

scholarly journals Evolution of Labrador Sea–Baffin Bay: Plate or Plume Processes?

2017 ◽  
Vol 44 (3) ◽  
pp. 91-102 ◽  
Author(s):  
Alexander Lewis Peace ◽  
Gillian R. Foulger ◽  
Christian Schiffer ◽  
Ken J.W. McCaffrey
Keyword(s):  
Ad Hoc ◽  
Labrador Sea ◽  
Continental Lithosphere ◽  
The West ◽  
Baffin Bay ◽  
Bay Area ◽  
Oceanic Spreading ◽  
Davis Strait ◽  
Orogenic Belts ◽  
Le Canada

Breakup between Greenland and Canada resulted in oceanic spreading in the Labrador Sea and Baffin Bay. These ocean basins are connected through the Davis Strait, a bathymetric high comprising primarily continental lithosphere, and the focus of the West Greenland Tertiary volcanic province. It has been suggested that a mantle plume facilitated this breakup and generated the associated magmatism. Plume-driven breakup predicts that the earliest, most extensive rifting, magmatism and initial seafloor spreading starts in the same locality, where the postulated plume impinged. Observations from the Labrador Sea–Baffin Bay area do not accord with these predictions. Thus, the plume hypothesis is not confirmed at this locality unless major ad hoc variants are accepted. A model that fits the observations better involves a thick continental lithospheric keel of orogenic origin beneath the Davis Strait that blocked the northward-propagating Labrador Sea rift resulting in locally enhanced magmatism. The Davis Strait lithosphere was thicker and more resilient to rifting because the adjacent Paleoproterozoic Nagssugtoqidian and Torngat orogenic belts contain structures unfavourably orientated with respect to the extensional stress field at the time.RÉSUMÉLa cassure entre le Groenland et le Canada a entraîné une expansion océanique de la mer du Labrador et de la baie de Baffin. Ces bassins océaniques sont reliés par le détroit de Davis, un haut bathymétrique constitué principalement de lithosphère continentale et de la province volcanique tertiaire de l'ouest du Groenland. Il a été suggéré qu'un panache du manteau a facilité cette cassure et généré le magmatisme associé. L’hypothèse d’une cassure produite par panache du manteau prédit que la première distension océanique, la plus importante, le magmatisme et l'expansion océanique initial se produisent là où le panache mantélique touche la croûte continentale. Or les observations dans la région de la mer du Labrador–baie de Baffin ne correspondent pas à ces prédictions. Et donc l'hypothèse du panache ne fonctionne pas dans cette région à moins que des facteurs ad hoc déterminants ne soient présents. Un modèle qui correspond mieux aux observations présuppose la présence d’une épaisse quille lithosphérique continentale d'origine orogénique sous le détroit de Davis qui aurait bloqué l’expansion océanique de la mer du Labrador vers le nord, ce qui aurait provoqué une augmentation du magmatisme localement. La lithosphère du détroit de Davis était plus épaisse et plus résistante à l’expansion océanique parce que les bandes orogéniques paléoprotérozoïques du Nagssugtoqidian et de Torngat renferment des structures défavorablement orientées par rapport au champ de contraintes d’extensions de l'époque.

Experimental, numerical and parametric studies on stress concentration factors of T-joints under tension

2021 ◽  
pp. 136943322110499
Author(s):  
Feleb Matti ◽  
Fidelis Mashiri
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Numerical Study ◽  
Hot Spot ◽  
Joint Models ◽  
Element Analysis ◽  
T Joints ◽  
Concentration Factors ◽  
Stress Concentration Factors ◽  
Good Agreement

This paper investigates the behaviour of square hollow section (SHS) T-joints under static axial tension for the determination of stress concentration factors (SCFs) at the hot spot locations. Five empty and corresponding concrete-filled SHS-SHS T-joint connections were tested experimentally and numerically. The experimental investigation was carried out by attaching strain gauges onto the SHS-SHS T-joint specimens. The numerical study was then conducted by developing three-dimensional finite element (FE) T-joint models using ABAQUS finite element analysis software for capturing the distribution of the SCFs at the hot spot locations. The results showed that there is a good agreement between the experimental and numerical SCFs. A series of formulae for the prediction of SCF in concrete-filled SHS T-joints under tension were proposed, and good agreement was achieved between the maximum SCFs in SHS T-joints calculated from FE T-joint models and those from the predicted formulae.

A mantle plume origin for the Siberian traps: uplift and extension in the West Siberian Basin, Russia

Lithos ◽  
2005 ◽  
Vol 79 (3-4) ◽  
pp. 407-424 ◽  
Author(s):  
Andrew D. Saunders ◽  
Richard W. England ◽  
Marc K. Reichow ◽  
Rosalind V. White
Keyword(s):  
Mantle Plume ◽  
The West ◽  
Siberian Traps ◽  
West Siberian Basin

scholarly journals A wireless subglacial probe for deep ice applications

2012 ◽  
Vol 58 (211) ◽  
pp. 841-848 ◽  
Author(s):  
C.J.P.P. Smeets ◽  
W. Boot ◽  
A. Hubbard ◽  
R. Pettersson ◽  
F. Wilhelms ◽  
...  
Keyword(s):  
Water Pressure ◽  
Greenland Ice Sheet ◽  
Depth Range ◽  
Measured Temperature ◽  
Transmission Power ◽  
The West ◽  
System A ◽  
Antenna Type ◽  
First Results ◽  
Good Agreement

AbstractWe present the design and first results from two experiments using a wireless subglacial sensor system (WiSe) that is able to transmit data through 2500 m thick ice. Energy consumption of the probes is minimized, enabling the transmission of data for at least 10 years. In July 2010 the first prototype of the system was used to measure subglacial pressure at the base and a temperature profile consisting of 23 probes in two 600 m deep holes at Russell Glacier, a land-terminating part of the West Greenland ice sheet near Kangerlussuaq. The time series of subglacial pressure show very good agreement between data from the WiSe system and the wired reference system. The wireless-measured temperature data were validated by comparison with the theoretical decrease of melting point with water pressure inside the water-filled hole directly after installation. To test the depth range of the WiSe system a second experiment using three different probe types and two different surface antennas was performed inside the 2537 m deep hole at NEEM. It is demonstrated that, with the proper combination of transmission power and surface antenna type, the WiSe system transmits data through 2500 m thick ice.

scholarly journals Deformation prediction analysis of vertical displacement of deep foundation pit based on LIBSVM

2020 ◽  
Vol 206 ◽  
pp. 01021
Author(s):  
Yueyao Zhao ◽  
Jiawei Zhang ◽  
Haojie Li
Keyword(s):  
Support Vector Machine Model ◽  
Hot Spot ◽  
Vertical Displacement ◽  
Support Vector ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Machine Model ◽  
Deformation Prediction ◽  
Deep Foundation Pit ◽  
Good Agreement

The reliable prediction of the surface vertical displacement deformation of deep foundation pits is of great significance to the excavation of large foundation pits. The support vector machine model (LIBSVM) has become a hot spot in the prediction of deep foundation pit deformation and provides a new prediction for the deformation of deep foundation pits. In this paper, taking the deep foundation pit of Daoxianghu Road Station in xx as an example, a prediction model of vertical displacement on the ground is established based on LIBSVM and analysis shows that the prediction results based on the model are in good agreement with the measured data, and the MSE reaches 0.0323. The model is effective and has an effective prospective skill.

Assessing the Roles of Three Eddy Types in Restratifying the Labrador Sea after Deep Convection

2011 ◽  
Vol 41 (11) ◽  
pp. 2102-2119 ◽  
Author(s):  
Renske Gelderloos ◽  
Caroline A. Katsman ◽  
Sybren S. Drijfhout
Keyword(s):  
Time Scales ◽  
Deep Convection ◽  
Early Spring ◽  
Labrador Sea ◽  
Boundary Current ◽  
Key Factors ◽  
The West ◽  
Warm Core ◽  
Water Formation ◽  
Dense Water Formation

Abstract Restratification after deep convection is one of the key factors in determining the temporal variability of dense water formation in the Labrador Sea. In the subsurface, it is primarily governed by lateral buoyancy fluxes during early spring. The roles of three different eddy types in this process are assessed using an idealized model of the Labrador Sea that simulates the restratification season. The first eddy type, warm-core Irminger rings, is shed from the boundary current along the west coast of Greenland. All along the coastline, the boundary current forms boundary current eddies. The third type, convective eddies, arises directly around the convection area. In the model, the latter two eddy types are together responsible for replenishing 30% of the winter heat loss within 6 months. Irminger rings add another 45% to this number. The authors’ results thus confirm that the presence of Irminger rings is essential for a realistic amount of restratification in this area. The model results are compared to observations using theoretical estimates of restratification time scales derived for the three eddy types. The time scales are also used to explain contradicting conclusions in previous studies on their respective roles.

Early Tertiary basalts from the Labrador Sea floor and Davis Strait region

1989 ◽  
Vol 26 (5) ◽  
pp. 956-968 ◽  
Author(s):  
D. B. Clarke ◽  
B. I. Cameron ◽  
G. K. Muecke ◽  
J. L. Bates
Keyword(s):  
Volcanic Rocks ◽  
Labrador Sea ◽  
Baffin Island ◽  
Nd Isotope ◽  
Sea Floor ◽  
West Greenland ◽  
Depleted Mantle ◽  
Davis Strait ◽  
Isotope Systematics ◽  
Seawater Exchange

Fine- to medium-grained, phyric and aphyric basalt samples from ODP Leg 105, site 647A, in the Labrador Sea show little evidence of alteration. Chemically, these rocks are low-potassium (0.01–0.09 wt.% K2O), olivine- to quartz-normative tholeiites that compare closely with the very depleted terrestrial Paleocene volcanic rocks in the Davis Strait region of Baffin Island and West Greenland. However, differences exist in the Sr–Nd isotope systematics of the two suites; the Labrador Sea samples have ε Nd values (+9.3) indicative of a more depleted source, and are higher in 87Sr/86Sr (0.7040), relative to the Davis Strait basalts (ε Nd +2.54 to +8.97; mean 87Sr/86Sr 0.7034). The higher 87Sr/86Sr in the Labrador Sea samples may reflect seawater exchange despite no petrographic evidence for significant alteration. The Labrador Sea and early Davis Strait basalts may have been derived from a similar depleted mantle source composition; however, the later Davis Strait magmas were generated from a different mantle. None of the Baffin Island, West Greenland, or Labrador Sea samples show unequivocal geochemical evidence for contamination with continental crust.

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