The seaway was populated with a variety of marine reptiles, including mosasaurs, plesiosaurs, and giant turtles. There were sharks, fish, and coiled ammonites. The sediments were deposited by turbidity currents (underwater landslides) of the edge of coastal deltas. The most important aspect of the deltas and coastal plains is that they were covered with tropical vegetation, swamps, and coastal estuaries.
The vegetation that didn't decay away was compressed into coal, and coal was the economic heart of Nanaimo. From 1848 to as late as the 1950s, coal was mined underground, following seams that sloped towards the bay. Miles and miles of tunnels were carved, reaching depths of 180 meters (nearly 600 feet). Many of the tunnels reached below sea level, and below the docks. Miners were literally working under the bay, able to hear the boats above as they worked. For many years the coal was shipped to San Francisco.
was recently destroyed during construction work).
Beyond the interpretive site, the trail climbs to the petroglyphs themselves. Fences are in place to keep people off the artwork. In this near-rainforest environment, it's amazing that the carvings haven't been more severely eroded. We found the rock exposures covered with forest duff and moss.
In the next post, we'll describe what our students actually did get to see. Despite the rain, we had a pretty good day, as it turned out.