Mesozoic and older rift basins on the SE Greenland Shelf offshore Ammassalik

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doi: 10.1144/SP447.15
Author(s): Gerlings, Joanna; Hopper, John R.; Fyhn, Michael B. W.; Frandsen, Nicolas
Author Affiliation(s): Primary:
Geological Survey of Denmark and Greenland, Coppenhagen, Denmark
Other:
University of Copenhagen, Denmark
Volume Title: NE Atlantic region; a reappraisal of crustal structure, tectonostratigraphy and magmatic evolution
Volume Author(s): Péron-Pinvidic, G., editor; Hopper, John R.; Stoker, M. S.; Gaina, C.; Doornenbal, J. C.; Funck, T.; Arting, U. E.
Source: The NE Atlantic region; a reappraisal of crustal structure, tectonostratigraphy and magmatic evolution, edited by G. Péron-Pinvidic, John R. Hopper, M. S. Stoker, C. Gaina, J. C. Doornenbal, T. Funck and U. E. Arting. Special Publication - Geological Society of London, 447(1), p.375-392. Publisher: Geological Society of London, London, United Kingdom. ISSN: 0305-8719 CODEN: GSLSBW
Note: In English. 70 refs.; illus., incl. sects., sketch maps
Summary: Seismic reflection data and shallow cores from the SE Greenland margin show that rift basins formed by the mid- to Late Cretaceous in the offshore area near Ammassalik. Here termed the Ammassalik Basin, this contribution documents the area using reprocessed older shallow seismic reflection data together with a more recent, commercial deep seismic reflection profile. The data show that the basin is at least 4 km deep and may be regionally quite extensive. Interpretation of gravity anomaly data indicate that the basin potentially covers an area of nearly 100 000 km2 The sediments in the basins are at least of Cretaceous age, as indicated by a sample from just below the basalt cover that was dated as Albian. Dipping sediment layers in the basins indicate that older sediments are present. Comparison of the data to the conjugate Hatton margin where older basins are exposed beneath the volcanic cover shows similar stratigraphy of similar ages. Reconstructions of the position of the basin during the Permian-Triassic and Jurassic suggest that older sedimentary strata could also be possible. In contrast to the conjugate Hatton margin, possible older strata subcrop out below the seafloor along the shallow margin, providing a future opportunity to sample some of the oldest sediments to determine the onset of rifting between SE Greenland and the Hatton margin.
Year of Publication: 2017
Research Program: ODP Ocean Drilling Program
Key Words: 16 Structural Geology; 20 Geophysics, Applied; Albian; Ammassalik Basin; Arctic region; Atlantic Ocean; Basins; Bathymetry; Continental shelf; Cretaceous; Denmark Strait; Geophysical methods; Geophysical profiles; Geophysical surveys; Gravity anomalies; Greenland; Igneous rocks; Jurassic; Leg 152; Leg 163; Leg 163X; Lower Cretaceous; Marine environment; Mesozoic; Middle Cretaceous; North Atlantic; ODP Site 917; ODP Site 988; Ocean Drilling Program; Ocean basins; Ocean floors; Paleozoic; Permian; Plate tectonics; Reconstruction; Reflection methods; Rifting; Sedimentary basins; Sediments; Seismic methods; Seismic profiles; Shelf environment; Stratigraphic units; Stratigraphy; Surveys; Tectonics; Triassic; Upper Cretaceous; Volcanic rocks
Coordinates: N624012 N632930 W0372737 W0394939
N633000 N654500 W0340000 W0401500
N632930 N632930 W0394939 W0394939
N654215 N654215 W0345216 W0345216
Record ID: 2017041935
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from The Geological Society, London, London, United Kingdom