Open AccessStructure of the continental margin of South‐eastern Greenland
Author(s) -
Featherstone P. S.,
Bott M. H. P.,
Peacock J. H.
Publication year - 1977
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1977.tb01282.x
Subject(s) - geology , continental margin , fault scarp , magnetic anomaly , paleontology , unconformity , continental shelf , seafloor spreading , oceanic crust , quaternary , passive margin , gravity anomaly , seismology , tectonics , subduction , oceanography , rift , oil field
Summary The paper describes the interpretation of geophysical observations across the Southeastern Greenland continental margin between 58° and 65° N. South of 63°, magnetic anomaly 24 is the earliest recognizable oceanic anomaly. North of 63°, anomalies 23 and 24 cut out against the margin and there is a complementary widening of ocean floor of this age on the opposite Rockall Margin north of Hatton Bank; this is attributed to local westward migration of the spreading axis north of 63° shortly after the split. Airgun and sparker profiles indicate the presence of three major sediment groups. Two groups of Tertiary age are separated by an erosional unconformity beneath the rise north of 62°. The overlying group is interpreted as comprising mainly contour current deposits of later Tertiary age, and the underlying group as lithified oozes of about Eocene age. Below the Tertiary sediments, older seaward dipping reflectors occur between anomaly 24 and the slope. These are interpreted as Mesozoic sediments overlying subsided continental crust. The oceanic–continental crustal boundary is recognized from magnetic anomalies and seismic profiles as occurring to the east of this subsided region, and lies up to 80km seaward of the present scarp which is interpreted as an erosional feature cut by contour currents. Gravity profiles indicate that the main change in crustal thickness associated with the margin occurs landward of the scarp north of 63° but corresponds more nearly to the scarp further south.