Iceland is geologically quite young, and mostly formed from volcanic processes, so fossils there are rare. The oldest fossils found in Iceland are from the Miocene, about 15 mya, and are plant remains. In addition to plant remains, fossilized remains of insects from the Miocene and Pliocene have been found. Miocene and Pliocene fossil sites are found mainly in the West of Iceland and the Westfjords. Remains of invertebrates have been found In Ice age strata, especially in fresh water and marine sediments]]. It is rare to find fossil remains of land animals in Iceland, although remains of deer bones have been found.