Travels in Cascadia: Victoria B.C., the City of Mutton Rocks

The next stop in our recent travels through Cascadia was the city of Victoria on Vancouver Island in British Columbia. We got there by way of a ferry from Port Angeles, Washington, as described in the last post. Victoria is an attractive city, one of the most temperate in Canada, given its location on the Pacific shoreline (the adjacent ocean moderates the seasonal temperature extremes). It is also unique in another respect. The city is partially constructed on bedrock (the solid rock that underlies surface soils and sediments), and the land was under a vast 1,000 meter thick ice sheet only 14,000 years ago.

This geologically unique combination means that Victoria is sort of a city of mutton rocks.

I imagine that sentence needs explanation...

The term roche moutonnée describes an asymmetrical glacially scoured rock outcrop that has a smooth slope on the side facing the flowing ice, and a steep cliff on the side where the glacier pulled away from the outcrop ("stoss and lee structure" is a related term). The scale can range from a few meters to many hundreds. They are common features in regions of bedrock that have been scoured by massive continental ice sheets, such as happened in Victoria. One of the tallest hills within the city, Mt. Tolmie (below), is an excellent example. In the picture one can see the gently sloping forested flank on the left side of the hill, and the steeper plucked side to the right.

Mt. Tolmie, a roche moutonnée in Victoria

The problem with roche moutonnée as a geological term is that we geologists can only barely agree on its meaning. It's derived from French, and the "roche" part isn't a problem. It means "rock". But "moutonnée" is the tricky aspect. It can be translated loosely as "sheep" (think "mutton""), but not exactly (French: "mouton"). Moutonnée (with the extra e's) translates to "frizzy", and is taken as a reference to sheep's wool. The term originated in the 1700s with a naturalist named Horace-Bénédict de Saussure (it would be decades before the term "geologist" was coined) who noted that the rocks looked like a type of wig apparently well-known at the time whose locks were held in place with mutton grease. Except that there seem to be few or no references to wigs that were actually called that (the closest version was a tête de mouton).

So we teachers are left with trying to define the term as meaning "rock sheep" based on the nebulous idea that the rocks look like sheep grazing in meadows. Which they really don't. But it's still easier than trying to describe obscure French wigs from the 1700s and mutton grease.

There are consequences to building on such rocky landscapes. There are plenty of large patches of glacial till that are easy to plane off with a bulldozer for building construction, but when the rock crops out, allowances have to be made. Perhaps it might involve blasting to construct a flat foundation. The rock is pretty tough stuff, gabbro, diorite, and greenstone of the Wrangellia terrane, dating back to the era of dinosaurs.

There are problems in this kind of situation. When the Empress Hotel (see the picture above) was constructed in 1904-1905 it was placed partly on solid rock and partly on mud-rich sediments. Complications quickly ensued. The south part of the building subsided several centimeters within the first year and ultimately sank about a meter. It's a real headache for those who must maintain the building.

Still, Victoria is a truly beautiful city, and the city has a unique personality. The city has miles of coastline, and there are dozens of scenic shoreline parks. We pulled up at Cattle Point to look at smaller roches moutonnée along with glacial scour marks and striations. Strangely enough, there was a piano sitting on the bluff. It was brightly painted, there was a bench, and the piano was in tune! I wondered what was going to happen to it if it rained, but then noticed a waterproof cover. We later found that there are five such pianos in the parks, and we were actually treated to a tune by a passing jogger, followed by a song by one of our students!

If you ever have a chance to visit Victoria, enjoy the city, but be sure to follow the shoreline drive to see the glacial heritage of the landscape (as well as seeing some dramatic coastal scenery). But the other thing you should do is to hike or drive to the summit of the mutton rocks of the city. Mt. Tolmie is a good choice within the city limits, or you can go just north of the city to the much higher summit of Mt. Douglas. It's a short hike from the parking lot to a summit with a 360 degree view of the region. The Olympic Mountains are visible across the Strait of Juan de Fuca to the south beyond the city, and the many islands of the Strait of Georgia and Saanich Inlet are visible to the north and east. Glacial polish, striations and grooves are present underfoot.

On the day we were there, I saw some unusual looking clouds far to the southeast. I took a few highly zoomed shots and forget about them until weeks later. I started working with the contrast and exposure of the picture and realized I had captured an image of Mt. Rainier across the Puget Sound. The volcano is more than 130 miles away (below)!

I had three main resources for the geology in and around the city:
The Geology of Southern Vancouver Island by Chris Yorath
Roadside Geology of Southern British Columbia by Bill Mathews and Jim Monger
Geology of British Columbia, A Journey Through Time by Sydney Cannings, JoAnne Nelson, and Richard Cannings.

Travels in Cascadia: Traversing the Salish Sea, and Leaving the USA

Morning in Port Angeles, looking across the Salish Sea

It was the third day of our journey through Cascadia, and after our exploration of the Olympic Peninsula, it was now time to leave the United States. We were in Port Angeles, Washington at the north end of the peninsula, and our route to Canada was by way of ferry across the Strait of Juan de Fuca. The landscape was undergoing a dramatic change. First of all we weren't in mountains anymore, we were crossing a sea. That seems an obvious point, but one has to wonder why the mountains abruptly end in a sea, and why similar mountains don't occur across the water. Second, we had reached the southern reach of the vast ice sheets that covered Canada and part of the United States during the Ice Ages that ended only around 12,000 years ago.

These two things, the end of the mountains and the end of the glaciers are related. The Strait we were crossing, along with the Strait of Georgia and the Puget Sound, are collectively known as the Salish Sea. The term was coined in the late 1980s as a way of recognizing the interconnectedness of these bodies of water as a single environmental entity. The name originated with the indigenous people who first colonized the landscape around the sea.

The Salish Sea (from http://blogs.agu.org/fromaglaciersperspective/2015/06/08/salmon-challenges-from-glaciers-to-the-salish-sea/)

The Salish Sea covers about 17,000 square kilometers (6,600 square miles), and has 7,470 kilometers (2,900 miles) of coastline, along with 419 islands. It is a unique ecosystem, a sea in the Pacific Northwest that is somewhat protected from the worst storm violence and wave action out of the Alaska region. Something like 8 million people call the shoreline home, in a megalopolis that extends from West Vancouver to Olympia. Along with people, there are 37 species of sea mammals, 172 species of birds, 247 species of fish, and over 3000 species of invertebrates.

The western margin of the Salish Sea is formed by the Olympic Peninsula and the mountains of Vancouver Island. The Strait of Juan de Fuca slices between the two landmasses. It was the strait that we were traversing on our way to the city of Victoria. 

The Olympic Peninsula is made up mostly of ocean floor sediments and basaltic rock pushed up as material was stuffed into the trench. Vancouver Island has a different origin. It is a piece of continental crust that traveled across the Pacific (at the feverish rate of a few inches per year) only to collide with the western edge of North America. Such far-traveled landmasses are called exotic terranes.

Source: http://www.deq.idaho.gov/regional-offices-issues/coeur-dalene/rathdrum-prairie-aquifer/geologic-history/

The Salish basin was shaped in large part by the ice sheets that covered essentially all of Canada and a good portion of the northern United States. As recently as 12,000 years ago, a mass of ice a mile (1.6 km) thick pushed south through the basin as far as Tacoma. A lobe of ice also extended west through what would become the Strait of Juan de Fuca.

The ferry ride took about 90 minutes to cover the 20 miles of open water between Washington and Vancouver Island. It's a beautiful ride, made all the more interesting as one realizes this entire body of water was once covered by ice. As one gets further out to sea, the higher snow-capped peaks of the Olympic Mountains come into view.

It may be that the water can get pretty choppy, especially during winter storms, but on my four trips across the strait, conditions were very calm. I almost felt like I was on a lake instead of a sea. We were still on dangerous "ground", though. The Strait of Juan de Fuca is not immune to the effects of huge earthquakes, whether in the immediate vicinity (along the Cascadia Subduction Zone), or from those at great distances (such as the 2011 Tohoku earthquake in Japan). The problem, of course, will be tsunamis.

Sometimes confined bodies of water can weaken the effect of tsunamis by dispersing the energy of the waves, but in some circumstances they can magnify the energy instead. There is some evidence of ancient tsunamis along the shorelines of some of the interior islands of the Salish Sea. The effects will probably muted compared to the damage along the Pacific Coast, but more developments are located there as well. On a positive note, the cities in the region are recognizing the threat and are talking action to minimize the damage (see an example here).

It was a beautiful cruise. Soon, we pulled into the harbor at Victoria and got ready to disembark. We were in Canada!

This post is part of a series on our field study of the geology and anthropology of British Columbia and the Pacific Northwest.

Vagabonding on Dangerous Ground: Stone Rings, Glaciers, and "Dinosaurs" on the Coast of the Salish Sea

We've got a mixed bag on this post...

Our vagabonding trip along the Cascadia Subduction Zone involved a desire to spend most nights camping, but we now we had reached Canada, our gear was all wet, and we were in one of the most beautiful cities in the world, Victoria. We decided to spend a few days in the comfort of a hotel and dry out a bit.

Victoria is an architecturally scenic city, but it is also a city of geology and archaeology. Some of the best parts are found in city parks like Beacon Hill and a series of shoreline green areas (although not so green in this dry year). We spent some time here last year, but I was flabbergasted to find I had missed an obvious link to the past that had been in plain view. It was a group of stone rings on the slope of Beacon Hill above Finlayson Point, right next to Mile Zero of the Trans-Canada Highway.

The stone rings were burial sites of the First Nation Songhees people. When Europeans established the city in the middle 1800s, there were several dozen of these rings on the hill, but the new colonizers were not particularly interested in preserving evidence of the past. They removed most of the stones and used them elsewhere. By the 1980s only four rings remained on the slope below Beacon Hill, hidden from sight by a thick growth of vegetation. In 1986, the parks department removed the vegetation, and then bulldozed the stone rings to facilitate mowing. They didn't realize what they were doing. Archaeologists directed to crews to replace the stones as best as could be remembered, and there were promises to protected the site and to provide interpretive signage. A low fence surrounds the rings, but when we were there, I didn't see any signs explaining the site.

The parks in the city of Victoria are good places to see the only dinosaurs remaining on planet Earth. They are of course the avian dinosaurs, the only members of the dinosaurian clan to survive the great extinction event at the end of the Cretaceous period. At Beacon Hill, we saw several large bird species, including a Peacock. Seen only from the knees down, they look terrifying, as scary as any T-rex.

There was also a rookery of Great Blue Herons. A juvenile was hanging out in the low branches of a tree by the pond, and the adults seemed to be patrolling the area from high perches in the tallest trees. Every few minutes they erupted into an other-worldly shrieking, and there was a commotion up in the crowns of the trees. We couldn't see what they were upset about.

After a few minutes the reason became clear. They were at war with raptors. There was a pair of Bald Eagles trying to attack the nestlings and eggs in the rookery. It was a life and death battle going on over our heads (for more pictures of the event, check out my story at Geotripper's California Birds).

We continued along the coast to take in the coastal parks, and to climb one of the highest peaks in the Victoria area. It was a good way to see evidence of the glacial heritage of this landscape.

Direct evidence exists for only two advances of glacial ice across this region, but there were undoubtedly many more. The youngest events tended to erase the deposits of the earlier advances of ice. Soils obscure many of the glacially carved rocks, so the best place to search for glacial features was along the coastline where wave erosion removes the soil cover. 

The coastal drive provided many examples of glacial polish, striations, and grooves. The smoothed off rocks provided clear exposures of the ancient metamorphic rocks that underlie this part of Vancouver Island. The rocks are called the Wark or Colquitz gneiss, and they formed as part of Wrangellia, a terrane that formed hundreds or thousands of miles away across the Pacific. It was accreted to the North American continent about 100 million years ago during the Cretaceous Period. I had a pleasant teaching moment when some older ladies who were enjoying the view wondered why the strange man was taking pictures of the rocks rather than the coastline. They politely said thank you at the end of the long explanation (I get that a lot).

We then drove to the top of Mount Douglas (known by the Saanich people as pq̕áls or PKOLS), a 260 m (853 ft) hill that rises over Victoria, providing a 360 degree view of the region. The mountain provides several different biologic zones, including a Garry Oak woodland around the summit, one of the northernmost exposures of oak trees in North America. The lower slopes are covered by conifer forests.

The view is fantastic. It really is a wonderful spot to gain an appreciation of the regional geography. The Olympic Mountains were visible across the Strait of Juan de Fuca, and I'm told that Mt. Rainier is visible on the clearest days (it's over 130 miles away). The entire city of Victoria spreads out to the south.

To the north is the Saanich Peninsula, and the glacially scoured Strait of Georgia, the northern extension of the Salish Sea. The mountains of Vancouver Island recede into the distance. The island is huge, 460 kilometres (290 miles) in length and 80 kilometres (50 miles) in width.

The next day was a layover for us, and we mostly pretended to be tourists, visiting Butchart Gardens (you can read my somewhat heretical review of the place here). The following day we were going to be seafarers once more, crossing the Strait of Georgia onto the Canadian mainland, and the Sea to the Sky Highway. I was anxiously watching the weather, because we traveled there last year, and never saw it because of low overcast conditions. What would we would see?

Northern Convergence: Victoria, Finding Geology and a Rare Ecosystem in a Beautiful City

We start our blog journey through Canada with a view of alpine peaks, forests and birds. If the picture seems a little fuzzy, it's because it is a highly cropped view down one of the main avenues in the city of Victoria on Vancouver Island (below). And truth be told, the peaks are actually in the United States. They are the Olympic Mountains, across the Strait of Juan de Fuca. We had not gone far into Canada yet!

Victoria is a pretty little city (population around 80,000, with a suburban population of about 340,000) that feels a little like it was carved from a wilderness, being surrounded by deep forests and rocky shorelines. All cities are imposed on geology, and Victoria is a vivid example. Just 12,000 or 13,000 years ago, the entire region lay beneath thousands of feet of glacial ice.

Glacial landscapes are exceedingly uneven, and the city's most venerable building is a victim of that fact. The Empress Hotel, constructed in 1908 (and no, we didn't get a chance to have High Tea there), has settled unevenly because portions are built on bedrock and the remainder on looser soils. As a consequence, one part of the foundation is a full meter lower than the other.

I suppose it is useless to point out the "Victorian architecture" when we are discussing a visit to Victoria, but the city was one of the oldest British settlements on the west coast of North America (1843), and the city has kept the flavor of old Britain (although most of our restaurant servers had Aussie accents or mentioned that they spent time living in Modesto!). Carriage rides are a staple of the tourist trade, and the city parks have tried to replicate the kind of flower gardens found in London, but the geology in some ways refuses to cooperate: glaciers didn't cover London, but they covered Victoria. Irregular knobs of bedrock pop out everywhere, and in those spots the park engineers surrendered to nature. Beacon Hill Park was our first geologic stop on the second morning of our trip.

The rocks themselves are quite unlike the rocks found across the Strait in Olympic National Park. Instead of deposits formed deep inside a subduction zone complex, the rocks exposed in Beacon Hill Park are metamorphic rocks derived from gabbro and granodiorite, a mixture called a migmatite. These rocks are derived from deep in the crust. They may date to 200 or 400 million years ago. 

The rocks were abraded by the glaciers, forming small roche moutonnées or crag and tail features. Such rocks are smoothed off on one side and plucked on the other, forming an asymmetrical linear ridge.

It occurred to me that the natural areas of the park were dry and out of character compared to other parts of the northwest coast of America, a place I associate more with rainforests. And there were oak trees, something I've never associated with western Canada. I thought that the northwest was all about conifers. It turned out that we had stumbled on one of the rarest biologic entities in Canada, the Garry Oak Ecosystem. Yes, it's really called that. The Garry Oak (Quercus garryana) is the only native oak species found in Washington and British Columbia.

Victoria is the driest locality on the west coast of Canada, averaging only about 24 inches of precipitation a year, with little and sometimes no snow. The local climate benefits from the moderating effect of the Pacific Ocean and Strait of Juan de Fuca, and lies in the rain shadow of the Olympics and other coastal mountains. Douglas Fir could still thrive in a climate like this, but wildfires keep them at bay. The Garry Oak Ecosystem covers far less than 1% of the land area of British Columbia, and is considered highly endangered (mainly due to development). It's also a harbinger of the future. With global warming, the oak woodland may become more widespread due to warmer and drier conditions.

Beacon Hill itself offers stunning views of the Strait of Juan de Fuca with the Olympic Mountains on the horizon. The coastal strip leading down to Finlayson Point is covered by glacial deposits.

Where wave erosion has removed the loose sediments, fresh exposures of glaciated bedrock can be seen. The rocks have been scored by striations and groves.

The southwest corner of the park holds one human-made distinction. It is Mile '0' (really, kilometer '0') of the Trans-Canada Highway that transects the entirety of the nation of Canada. It a sense it was mile zero of our journey through Canada as well.

Our next post will explore some of the fascinating geology of Vancouver Island beyond the city boundaries of Victoria.

Ah, the Life of the Mariner! Well, Maybe...

Ah, the open sea! The adventures of the water world of planet Earth! The mysteries of the deep! Yes, it's the mariner's life for me. Well maybe, maybe not. It's hard to develop a real opinion on the basis of a single ferry ride across the Strait of Juan de Fuca. It sure was pretty, in any case.

The Port Angeles-Victoria ferry crosses the Juan de Fuca Strait that separates the Olympic Peninsula from Vancouver Island on the the Pacific Coast between the United States and Canada. Although the peninsula and the island are both situated in the same geographic location (the western coast of North America) and are only a few miles apart, they have few similarities. The Olympic Peninsula is composed of seafloor sediment and ocean crust that has been shoved to very high elevations by the Cascadia subduction zone. Vancouver Island has a sliver of some of these rocks, but is mostly composed of metamorphic rocks of the Wrangellia Terrane, a collection of Paleozoic and Mesozoic rocks that formed someplace else, maybe thousands of miles away, and which was slammed (geologically speaking) into the west coast by subduction zone and transform fault movements.

We are out doing a bit of reconnaissance for our field studies class that meets next week. We got out to the Sooke region along the south island for a look at the Crescent terrane, and some nice erosional potholes along the Sooke River. Details to follow in later posts!

Oh, and there were lagomorphs too! Cute ones. We passed dozens of them grazing in a freeway median of all places (no, I didn't stop on the freeway for the picture; this one was at East Sooke Regional Park).

The nice thing about traveling this far north is that the sun sets late (this statement does not apply in winter, though!). We had this wonderful view of the Olympic Mountains across the Strait of Juan de Fuca around 8:30, and still had an hour of light.

I guess I'm still a landlubber though...I love the solid ground and the rocks too much.