Episodes of sea-floor spreading recorded by the North Atlantic basement

1971 ◽  
Vol 12 (3) ◽  
pp. 211-234 ◽  
Author(s):  
P.R. Vogt ◽  
G.L. Johnson ◽  
T.L. Holcombe ◽  
J.G. Gilg ◽  
O.E. Avery
Author(s):  
Michael Larsen ◽  
Morten Bjerager ◽  
Tor Nedkvitne ◽  
Snorre Olaussen ◽  
Thomas Preuss

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Larsen, M., Bjerager, M., Nedkvitne, T., Olaussen, S., & Preuss, T. (2001). Pre-basaltic sediments (Aptian–Paleocene) of the Kangerlussuaq Basin, southern East Greenland. Geology of Greenland Survey Bulletin, 189, 99-106. https://doi.org/10.34194/ggub.v189.5163 _______________ The recent licensing round in the deep-water areas south-east of the Faeroe Islands has emphasised the continued interest of the oil industry in the frontier areas of the North Atlantic volcanic margins. The search for hydrocarbons is at present focused on the Cretaceous– Paleocene succession with the Paleocene deepwater play as the most promising (Lamers & Carmichael 1999). The exploration and evaluation of possible plays are almost solely based on seismic interpretation and limited log and core data from wells in the area west of the Shetlands. The Kangerlussuaq Basin in southern East Greenland (Fig. 1) provides, however, important information on basin evolution prior to and during continental break-up that finally led to active sea-floor spreading in the northern North Atlantic. In addition, palaeogeographic reconstructions locate the southern East Greenland margin only 50–100 km north-west of the present-day Faeroe Islands (Skogseid et al. 2000), suggesting the possibility of sediment supply to the offshore basins before the onset of rifting and sea-floor spreading. In this region the Lower Cretaceous – Palaeogene sedimentary succession reaches almost 1 km in thickness and comprises sediments of the Kangerdlugssuaq Group and the siliciclastic lower part of the otherwise basaltic Blosseville Group (Fig. 2). Note that the Kangerdlugssuaq Group was defined when the fjord Kangerlussuaq was known as ‘Kangerdlugssuaq’. Based on field work by the Geological Survey of Denmark and Greenland (GEUS) during summer 1995 (Larsen et al. 1996), the sedimentology, sequence stratigraphy and basin evolution of the Kangerlussuaq Basin were interpreted and compared with the deep-water offshore areas of the North Atlantic (Larsen et al. 1999a, b).


2015 ◽  
pp. 302-330 ◽  
Author(s):  
Walter C. Pitman ◽  
Manik Talwani

1990 ◽  
Vol 38 ◽  
pp. 1-9
Author(s):  
Poul-Henrik Larsen ◽  
Lars Stemmerik ◽  
Troels F.D. Nielsen ◽  
David C. Rex

Field observations on Iamprophyric dykes in Revdal, Scoresby Land, suggest a Late Permian age and the dykes would thus represent magmatism related to Permian rifting and basin formation, whereas K-Ar age determinations and chemistry suggest a Tertiary age. It is concluded that the dykes probably are Tertiary and never penetrated Upper Permian sediments due to chilling and fracturing at the base of Upper Permian water rich sediments. The dykes most likely belong to a period of alkaline magmatism that followed the onset of sea floor spreading in this part of the North Atlantic around 55 Ma ago.


Author(s):  
John McManus

SynopsisOrganisms and sea floor sediments respond to a number of physical and physico-chemical factors, the understanding of which permits identification of areas with typical and potentially aberrant habitats and deposits. After a resumé of the bathymetry of Scottish water tides, tidal current and residual currents stemming from the circulation in the North Atlantic are examined. The salinity and temperature interrelationships in many areas are summarised in open shelf waters, sea lochs and estuaries. Sea floor sediments commonly reflect reworking of glacial deposits coupled with varying indigenous populations of organisms which contribute skeletal debris to the particulate assemblages characterising the bed.


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