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

• Main Authors: Poul-henrik Larsen, Lars Stemmerik, Troels F. D. Nielsen, David C. Rex
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Greenland; Scoresby; Scoresby Land; East Greenland; North Atlantic; Scoresby land
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.512.3782; http://2dgf.dk/xpdf/bull38-01-02-1-9.pdf

cs Field observations on lamprophyric 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.