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Tectonic implications of paleomagnetic data from sills and dykes in the Sverdrup Basin, Canadian Arctic
Author(s) -
Jackson K. C.,
Halls H. C.
Publication year - 1988
Publication title -
tectonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.465
H-Index - 134
eISSN - 1944-9194
pISSN - 0278-7407
DOI - 10.1029/tc007i003p00463
Subject(s) - geology , paleomagnetism , sverdrup , sill , apparent polar wander , cretaceous , polar wander , clockwise , paleontology , structural basin , fold (higher order function) , tectonics , seismology , petrology , mechanical engineering , engineering
Mesozoic intrusives, 71 sills and 12 dykes, from different structures in the folded eastern Sverdrup Basin contain stable, well‐grouped paleomagnetic directions of both normal and reverse polarity. The mean direction is 274°, +79°, k=173, α 95 =3.7°, with a corresponding pole position at 157°, 67°N, k=61, A 95 =6.6°. The paleomagnetic fold test shows that the major deformation, involving tilting of strata around strike, postdated the emplacement of sills and dykes. Minor preintrusion deformation may also have occurred, but, more importantly, an offset of the paleopole from the Cretaceous section of the polar wander path permits a postintrusion anticlockwise rotation of eastern Sverdrup Basin of about 15+/−20° with respect to stable North America. If the intrusives are Cretaceous, the degree of rotation is close to that (11°) estimated for Greenland during the opening of the Labrador Sea. No positive evidence has been found to support models of distributed shear with block rotations to accommodate the contentious northeast translation of Greenland along the Nares Strait.