The M 2 tide in the Labrador Sea, Davis Strait and Baffin Bay

1966 ◽  
Vol 13 (5) ◽  
pp. 1038
Keyword(s):  
Labrador Sea ◽  
Baffin Bay ◽  
Davis Strait

scholarly journals Full-fit reconstruction of the Labrador Sea and Baffin Bay

2013 ◽  
Vol 5 (2) ◽  
pp. 917-962 ◽  
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).

scholarly journals Faults and fractures in central West Greenland: onshore expression of continental break-up and sea-floor spreading in the Labrador – Baffin Bay Sea

2006 ◽  
Vol 11 ◽  
pp. 185-204 ◽  
Author(s):  
Robert W. Wilson ◽  
Knud Erik S. Klint ◽  
Jeroen A.M. Van Gool ◽  
Kenneth J.W. McCaffrey ◽  
Robert E. Holdsworth ◽  
...  
Keyword(s):  
Dominant Role ◽  
Field Studies ◽  
Labrador Sea ◽  
Tectonic Structures ◽  
Two Phase ◽  
Baffin Bay ◽  
Fault Systems ◽  
Davis Strait ◽  
Regional Tectonic ◽  
Sea Floor Spreading

The complex Ungava fault zone lies in the Davis Strait and separates failed spreading centres in the Labrador Sea and Baffin Bay. This study focuses on coastal exposures east of the fault-bound Sisimiut basin, where the onshore expressions of these fault systems and the influence of pre-existing basement are examined. Regional lineament studies identify five main systems: N–S, NNE–SSW, ENE–WSW, ESE–WNW and NNW–SSE. Field studies reveal that strike-slip movements predominate, and are consistent with a ~NNE–SSW-oriented sinistral wrench system. Extensional faults trending N–S and ENE–WSW (basement-parallel), and compressional faults trending E–W, were also identified. The relative ages of these fault systems have been interpreted using cross-cutting relationships and by correlation with previously identified structures. A two-phase model for fault development fits the development of both the onshore fault systems observed in this study and regional tectonic structures offshore. The conclusions from this study show that the fault patterns and sense of movement on faults onshore reflect the stress fields that govern the opening of the Labrador Sea – Davis Strait – Baffin Bay seaway, and that the wrench couple on the Ungava transform system played a dominant role in the development of the onshore fault patterns.

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.  

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.

scholarly journals Cenozoic Relative Movements of Greenland and North America by Closure of the North Atlantic-arctic Plate Circuit: the Labrador Sea, Davis Strait and Baffin Bay

2021 ◽  
Author(s):  
Annabel Causer ◽  
Graeme Eagles ◽  
Lucía Pérez-Díaz ◽  
Jürgen Adam
Keyword(s):  
North America ◽  
North Atlantic ◽  
Data Uncertainty ◽  
Plate Motion ◽  
Labrador Sea ◽  
Motion Model ◽  
Continental Breakup ◽  
Baffin Bay ◽  
The North ◽  
Davis Strait

Abstract The processes that accommodated plate divergence between Greenland and North America are most confidently interpretable from a short-lived (61-42 Ma) sequence of magnetic isochrons in the Labrador Sea. Understanding of the preceding and following periods is impeded by the lack of clear isochrons in the basin’s continent-ocean transition and axial zones. By closing the regional plate circuit, we build and interpret a detailed plate motion model for Greenland and North America that is applicable in, but unaffected by data uncertainty from, the Labrador Sea, Davis Strait, and Baffin Bay. Among our findings, we show the Labrador Sea initially opened during a ~8.3-16.5 Myr-long period of focused extension culminating in continental breakup no earlier than 74-72 Ma, and experienced a ~80° change in spreading direction around 56 Ma. We describe some possible implications for the accommodation of strain prior to continental breakup and during extreme spreading obliquity.

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