Jul 1, 2002 | Marmot, Summer 2002

Mount Washington Rocks

Eighty-five million years ago, no one skied at Mount Washington. That's because the mountain likely didn't exist that far back in history, says geologist Peter Mustard.

Peter Mustard is a Professor of Earth Sciences at Simon Fraser University in Burnaby. He spent part of last fall living at Mount Washington and mapping different rock types of the Trent River and other local areas to provide the base for future geological studies. He was back in the Comox Valley area in June 2002 to do some more mapping of cut blocks west of Mount Washington.

“If you wanted to go skiing 85 million years ago, there was no place to go,” he said. Not only was most of the region under water, it was also flat. “This is a new idea.”

Recent research – including Mustard’s mapping project – indicates that, contrary to popular belief, the Beaufort Range did not exist 85 million years ago. A geology guide for Strathcona Park suggests that there was a large mountain range located approximately where the Beaufort Range is now, but “we’re pretty sure now that didn’t exist.”

The other reason no one would have been skiing at Mount Washington 85 million years ago is that temperatures in this region were at least 10 degrees Celsius warmer than they are now. “All of the plants we find are sub-tropical types – the stuff we would find in Mexico,” Mustard said. That could mean one of two things: that when this area was all sand beaches and shallow seas, the land mass was farther south, closer to the Equator; or that the climate was just that much warmer.

“There probably was no winter as we know it. It would probably have been like winter in California or Mexico. So there was no snow.” The geology of Mount Washington is not unique to this area of Vancouver Island – although part of it is more rare than others, Mustard said. There are three basic rock types ˜ sedimentary, volcanic and quartz diorite (granite that is rich in quartz) – and they’re plainly visible to skiers and summer visitors.

The first type of rock is called the Karmutson Formation or Karmutson Volcanics, which is made up of volcanic rock. They’re the greenish rocks visible in the lower parking lot; they’re from the Triassic Period and are approximately 220 million years old.

“They’re very common,” says Mustard. Above the Karmutson Volcanics, as you drive up the Strathcona Parkway from the main parking lot, is sedimentary rock from the Nanaimo Group. This group of rock stretches from Campbell River in the north along the Island’s eastern shoreline to the Saanich Peninsula in the south, and as far west as Port Alberni. The Nanaimo Group is from the Cretaceous Period and its rocks are 65 to 90 million years old.

The Nanaimo Group comprises the sandstones, coals, etc. that form some of the mountains of Strathcona Park. They are also the rocks where coal was mined in the Comox Valley, and from where many of the fossils in the Courtenay Museum are found.

“They’re really well-exposed in the main parking lot” and on the lower ski slopes, Mustard said. In fact, a small coal seam was discovered in the main parking lot last year when the resort expanded the parking lot. The third type of rock, quartz diorite, is only about 45 million years old and comprises the mountain’s “Mile High” profile. It’s called the Mount Washington Intrusive and was formed when molten lava travelled upwards from the earth’s interior, looking for an exit. However, the intrusive didn’t make it to the surface; it cooled underground instead. The Mount Washington Intrusive is only visible now because millions of years of erosion have worn away the softer rock of the Nanaimo Group that surrounds the ski hill’s peak.

“Igneous rocks of this age occur throughout southern Vancouver Island, but the Mount Washington example is one of the largest and best exposed examples; thus, all these occurrences are commonly known as the Mount Washington Intrusive suite,” Mustard said.

These rocks are harder and more weather-resistant than others in the area, so they tend to stand out. They take longer to erode, too, which is why Mount Washington’s peak is still around while the sandstone around it has eroded.

The delineation between the Mount Washington Intrusive and the sedimentary rock is somewhere between the main parking lot and the lower runs, Mustard explained. However, because the ski slopes are covered with snow in the winter and grass and trees in the summer, locating the exact line is difficult.

While there may not have been snow when the geology of Mount Washington was formed, there was water – and lots of it. “Even up in those high mountains in Strathcona Park, most of those rocks have marine fossils in them,” he said. While paleontologists have discovered many marine specimens, like a mosasaur, elasmosaur and sea turtles, not one tooth or bone from a land-based dinosaur has been discovered anywhere from Campbell River to the American border.

Mustard guessed that there was some sort of sea barrier that separated the dinosaurs prevalent in the Alberta Badlands from Vancouver Island. “Either that, or we’re not looking hard enough.”

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