Photo of the Ordovician
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
Bhumigyan (Geology) dunia jon sab nonliving chij se banaa hae ke baare me parrhae hae.