The age of the Kap Washington Group volcanics

• Main Authors: Ole Larsen, Kap Washington
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1982
• Subjects: Arctic; Arctic Ocean; Greenland; Kane; Kap; Kap Kane; Kap Washington; Lockwood; North Greenland
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.563.3414; http://2dgf.dk/xpdf/bull31-01-02-49-55.pdf

The Kap Washington Group of peralkaline volcanics is exposed along the coast of North Greenland at C3 40°W. This coastal region is intruded by numerous NNE-NW-trending dolerite dykes of alkaline affinity. The volcanics and their basic intrusive counterparts appear to be related to the initial rifting in the Arctic Ocean basin. The timing of this rifting may be supported by accurate dating of the associated volcanic activity. An improved Rb/Sr age of 64±3 million years (i.e. approximately at the Cretaceous-Tertiary boundary) has been determined on rhyolitic lavas collected at Kap Kane, probably near the top of the volcanic sequence. The extrusive volcanic activity probably started already in late Cretaceous time, as in-dicated by fossil plant remains, found in sediments interbedded with the lavas on Lockwood 0.