Thursday, September 19, 2019

Travels in Cascadia: The Southernmost Fjord in Western North America: Howe's that Sound?

Our journey through the Pacific Northwest and British Columbia continued. We had spent several days on Vancouver Island, exploring Goldstream Provincial Park, Mt. Douglas and the Mutton Rocks of Victoria, Sitting Woman Falls, and the gabbro oceanic crust of East Sooke Park. It was now time to head back to the mainland and our goal was to explore the geologic environments of Howe Sound, the southernmost glacial fjord in western North America.

We would spend several days looking at this fascinating geological environment. To get there we would need to take a ferry from Nanaimo on Vancouver Island back to the mainland at Horseshoe Bay inside Howe Sound. We just missed an earlier ferry, so we cooled our heels for a couple of hours in the tourist traps at the ferry terminal. Our attention was distracted by a pair of otters hiding out in the shade beneath the ferry building.

After a few hours we were underway, leaving behind the fairly muted glacial topography of Vancouver Island, and heading towards the decidedly more mountainous country of the mainland. The main contrast was that glacial ice sheets covered Vancouver Island, but the mountains rose above the glaciers on the mainland. We could see the city of Vancouver off to the south.

As we scanned the horizon from the upper deck of the ferry, we could see that we were still definitely in the land of volcanoes. Off to the east we could just make out the lower flanks of Mt. Garibaldi, one of the northernmost of the Cascades Volcanoes. Garibaldi is one of the most unusual of the Cascades because a large portion of the edifice was erupted onto a glacier. When the glacier melted away at the end of the ice age, the flank of the volcano collapsed into the adjacent valley in a series of huge debris flows.
Mt. Garibaldi, with Howe Sound in the foreground

The clouds were playing hide and seek, and mostly 'hide' with the summit of Mt. Baker off to the south in Washington. The glacier-covered peak of Mt. Baker is geologically young, and the mountain seemed on the verge of erupting back in 1975, but it fizzled out to the disappointment of geologists and to the relief of everyone else.
Mt. Baker, partly hidden by clouds, from Howe Sound

My favorite sight from the ferry ride was of the Black Tusk or t'ak't'ak mu'yin tl'a in7in'a'xe7en in the language of the Squamish people, who considered the strangely shaped peak to be the landing place of the Thunderbird, a principle figure in First Nations mythology. In geological terms, the mountain is a deeply eroded stratovolcano, once like Mt. Baker or Mt. Hood, but now a spikey remnant of the original cone
The Black Tusk from Howe Sound

As noted before, Howe Sound is a glacial fjord, a deep bay with steep flanks that was carved by glaciers. It is a bit difficult to pick out the entrance from the Strait of Georgia because it includes several islands. The sound is 26 miles long, ending at the town of Squamish at the upper end. The urban center of Vancouver is just south of Howe Sound where there is more level ground.

The sound is full of geological delights. We would spend the next four days in the immediate vicinity. That's where we'll pick up the story next time.

Monday, September 9, 2019

The Way It Was: Yosemite on a September Saturday

Not what I was expecting...

I generally avoid Yosemite Valley in the summertime, and I try to avoid Saturdays especially, but I was a glutton for punishment; we hadn't been to the valley since last spring and were kind of curious about how it would be. We expected crowds and dryness and dust.
That's not what we found. In September, the meadows are often brown and the waterfalls dry. Instead, Bridalveil Meadow was green and filled with wildflowers, and Bridalveil Fall, while not roaring by any means, was flowing nicely. The wind occasionally picked up and blew the water in odd directions.
Even Yosemite Falls had a trickle. I don't know if it was left over from the spring, or if it was from the recent thunderstorms, but it was nice to see.
Half Dome is spectacular, no matter the time of year. The afternoon cumulus cloud buildup provided a nice backdrop.
Sentinel Rock is another towering cliff that is an incredible sight no matter the season. It's one of those rocks on the "wrong" side of the valley that is not noticed as often because it is opposite of Yosemite Falls. If it were anywhere else on the planet besides Yosemite, it would be a national landmark all on its own.
A late afternoon treat is the Valley View at the west end of Bridalveil Meadow. There's a small pullout, but it is often ignored by people rushing home from their day in the valley. We found a spot despite the traffic, and simply sat for awhile.
The wonderful thing about late summer is that the low water on the Merced River is often calm and provides a wonderful reflective surface. It was gorgeous and serene.

And that's the way it was...

Monday, September 2, 2019

Travels in Cascadia: You Can Have Your Niagara Falls, and I'll Have Mine...Goldstream Provincial Park, B.C.

Our journey through British Columbia last July continued. We were on Vancouver Island and were leaving the city of Victoria to catch the ferry back to the mainland at Nanaimo. But there were still some sights along the way. The town of Victoria was built on the lowlands at the south end of the island, but as we began traveling north the landscape grew more rugged and mountainous. The vast ice sheets of the last ice age covered the entire island, but the ice could not remove the tougher bedrock of the island's interior. Looking south from Malahat Summit (l,155 feet/352 meters) we could see the hills we had just explored, including the delightful Goldstream Provincial Park.
The park hosts a surprising variety of plant and animal life, due to a wide variety of habitats. Part of the value of the park is that it has not been logged, and thus preserves old-growth forests, including 700 year old Cedar trees. It includes an estuary/wetland at the end of the Finlayson Arm of the Strait of Georgia, part of the Salish Sea. The long inlet exists because the glaciers were able to exploit a fault zone that left the rocks weakened and broken. The Leech River Fault, a major terrane boundary, cuts through the park, dividing the Pacific Rim Terrane (the Leech River Complex) from Wrangellia. Wrangellia is made up of igneous intrusive rocks and metamorphic rocks from the Mesozoic Era, the age of the dinosaurs.
Looking south from the Nature Center one can see Mount Finlayson (below), another feature that indicates the presence of glaciers in the past. The rounded form of the mountain identifies it as a roche moutonnée, a larger-scale version of the rounded forms seen at Mt. Douglas and Mt. Tolmie in Victoria.
The title of today's post refers to one of the small delights of the park. The erosive action of the glaciers was oriented mostly north to south, and the ridgelines drop steeply into the valley containing the Finlayson Arm. Small creeks and rivers occasionally form modest waterfalls, including the easily accessed Niagara Falls. Visiting the waterfall, one realizes it was not named for the similarity of its volume to the better-known falls back east, but to the height. At 155 feet, it's just a bit shorter than Niagara's 167 feet (note the people at the bottom of the canyon for scale).
One might wonder why Goldstream Park has the name it has. The rocks of the Leech River Complex were altered by superheated mineralized water, and quartz veins with minor amounts of gold were emplaced in the area. The gold was discovered in 1858, and a minor rush involving perhaps 300 miners ensued a few years later. There was not a great deal of gold to be had, and the boom soon petered out, but the name remained. A few old tunnels and mines can still be seen in the park.
I know this is a geology blog, and most of the time I don't have much patience for trying to get pictures of deer, but as I was walking up the trail to the falls, I broke with tradition. Up ahead of me I could see some kind of four-footed animal, and it turned out to be the cutest little fawn ever. It was happy to share the trail with me for a few moments, until the rest of the crew caught up with me. It then took off into the underbrush.

Goldstream Provincial Park is west and north of Victoria on the Trans-Canada Highway 1. We were there on a holiday weekend and the parking lots filled quickly (we made some people very happy when our four vehicles left all at once). If you have the time and energy, a trail climbs to the summit of Mt. Finlayson.