|
Part 2: Margin Overviews |
Geological Survey of Denmark and Greenland, Thoravej 8, DK-2400 Copenhagen NV, Denmark jac{at}geus.dk
The Labrador Sea is a small oceanic basin that developed when the North American and Greenland plates separated. An initial period of stretching in Early Cretaceous time formed sedimentary basins now preserved under the continental shelves and around the margins of the oceanic crust. The basins subsided thermally during Late Cretaceous time and a second episode of tectonism took place during latest Cretaceous and early Paleocene time, before the onset of sea-floor spreading in mid-Paleocene time. Around the northern Labrador Sea, Davis Strait and in southern Baffin Bay, voluminous picrites and basalts were erupted at and shortly after the commencement of sea-floor spreading. Volcanism occurred again in early Eocene time at the same time as sea-floor spreading commenced in the northern North Atlantic. Farther southeast, along the Labrador and southern West Greenland margins, oceanic crust is separated from continental crust by highly stretched but non-magmatic transition zones which developed before sea-floor spreading. A complex transform zone, which developed during sea-floor spreading in late Paleocene and early Eocene time, separates continental and oceanic crust along the Baffin Island margin. The Greenland and Labrador ocean-continent transitions are asymmetric across the only available conjugate cross-sections. However, a cross-section through the Labrador margin farther north resembles the Greenland cross-section in the conjugate pair more than it does the Labrador cross-section of this pair. Consideration of the geological history of the area suggests that the non-magmatic transition zones may have formed by slow extension of a few millimetres per year through a period of 53 Ma during Cretaceous and early Paleocene time.
This article has been cited by other articles:
 |
|
 |
|
  A. G. Dore, E. R. Lundin, N. J. Kusznir, and C. Pascal Potential mechanisms for the genesis of Cenozoic domal structures on the NE Atlantic margin: pros, cons and some new ideas Geological Society, London, Special Publications, 2008; 306: 1 - 26. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. G. Direen, I. Borissova, H. M. J. Stagg, J. B. Colwell, and P. A. Symonds Nature of the continent ocean transition zone along the southern Australian continental margin: a comparison of the Naturaliste Plateau, SW Australia, and the central Great Australian Bight sectors Geological Society, London, Special Publications, 2007; 282: 239 - 263. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. B. Sorensen Stratigraphy, structure and petroleum potential of the Lady Franklin and Maniitsoq Basins, offshore southern West Greenland Petroleum Geoscience, 2006; 12: 221 - 234. [Abstract] [Full Text] [PDF]
|
|
