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Description Photo of the Ordovician - Silurian boundary, an example of marine transgression as exposed on the Southern tip of the Hovedøya island, Norway. Due to the folding of the caledonian mountain range, the layers have been inverted, leaving Ordovician granular limestone on top of the later Silurian brownish mudstone.
Date Summer 2007
Source Own work
Author Petter Bøckman


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