Paleontology and geology
During the Devonian, most of Alaska as we know it today had not yet begun to assemble. In the northern third of the state, marine conditions were widespread and diversefrom deep ocean floor to complex carbonate platforms derived from corals, molluscs and associated organisms. Tectonic activity resulted in widespread mountain building in the arctic and to the south and there is evidence of swampy areas filled with plants that eventually produced coal deposits. Devonian fossils of snails, brachiopods, and radiolarians are abundant.