Age determination from the Trondheim Region Caledonides, Norway: a preliminary report.
Abstract
Twenty-four potassium-argon age determinations have been made on metamorphic minerals and whole-rocks (phyllites) from the Caledonides of the Trondheim region, Norway. Nineteen of the apparent ages fall between 438 and 402 m.y., while 5 (4 hornblendes and 1 phyllite) range up to 570 m.y. Date greater than 438 m.y. are provisionally considered anomalous, and 438 +- 12 m.y. is tentatively suggested as a minimum age for the last metamorphic phase in this region.