Book Description

The orbicular rocks of Finland are various plutonic rocks. In this publication 29 bedrock and 61 boulder occurrences are described. Solitary boulders and boulder fans of orbicular rock are evidently derived from at least 50 separate bedrock occurences. Most of the orbicular rocks are recorded from Proterozoic bedrock (age 1.50-1.90 Ga), with relatively few discoveries from the Archaean basement areas (age 2.50-3.20 Ga). In addition, orbicular carbonatite has been encounteered in the late Devonian Sokli carbonatite intrusion (age 365 Ma).