scholarly journals Lamprophyric dykes in Revdal, Scoresby Land, East Greenland: conflicting field observations and K-Ar age determinations

1990 ◽  
Vol 38 ◽  
pp. 1-9
Author(s):  
Poul-Henrik Larsen ◽  
Lars Stemmerik ◽  
Troels F.D. Nielsen ◽  
David C. Rex
Keyword(s):  
North Atlantic ◽  
Upper Permian ◽  
Alkaline Magmatism ◽  
Field Observations ◽  
Late Permian ◽  
Sea Floor ◽  
The North ◽  
Basin Formation ◽  
Sea Floor Spreading ◽  
Age Determinations

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.

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
Keyword(s):  
North Atlantic ◽  
Sea Floor ◽  
The North ◽  
The North Atlantic ◽  
Sea Floor Spreading

Pre-basaltic sediments (Aptian–Paleocene) of the Kangerlussuaq Basin, southern East Greenland

2001 ◽  
pp. 99-106 ◽  
Author(s):  
Michael Larsen ◽  
Morten Bjerager ◽  
Tor Nedkvitne ◽  
Snorre Olaussen ◽  
Thomas Preuss
Keyword(s):  
North Atlantic ◽  
Deep Water ◽  
Sediment Supply ◽  
Basin Evolution ◽  
East Greenland ◽  
Sea Floor ◽  
North West ◽  
The North ◽  
The North Atlantic ◽  
Sea Floor Spreading

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).

Sea-Floor Spreading in the North Atlantic

2015 ◽  
pp. 302-330 ◽  
Author(s):  
Walter C. Pitman ◽  
Manik Talwani
Keyword(s):  
North Atlantic ◽  
Sea Floor ◽  
The North ◽  
The North Atlantic ◽  
Sea Floor Spreading

scholarly journals Nd and Sr isotope compositions from the Gardiner Complex, East Greenland Tertiary igneous province

1993 ◽  
Vol 40 ◽  
pp. 280-287
Author(s):  
Troels F. D. Nielsen ◽  
Paul M. Holm
Keyword(s):  
Isotopic Composition ◽  
North Atlantic ◽  
Alkaline Magmatism ◽  
Sr Isotope ◽  
East Greenland ◽  
The North ◽  
Early Tertiary ◽  
Igneous Province ◽  
The North Atlantic

The Gardiner Complex formed during the early Tertiary opening of the North Atlantic. The complex is strongly alkaline and referred to a zone of alkaline flank magmatism 100 km west of the melting anomaly in the initial rift of the North Atlantic. Earlier investigations have documented that most rocks of the complex can be referred to three suites which are all suggested to have been formed from a single parental melanephelinitic liquid. The Nd and Sr isotope compositions presented here support this conclusion. Minor deviations are believed to be due to interaction with Archaean basement. The isotopic characteristics suggest that the alkaline magmatism originated in a source similar to that of the contemporaneous picritic and basaltic tholeiites. The isotopic composition of the source is Jess depleted than pervalent mantle (PREMA) and sets an upper enrichment limit to the composition of the Icelandic plume component 50 Ma ago.

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