A Quick Visit to Portland
Mount Saint Helens is only 25 miles as the crow flies from Portland, so we stopped by our southern neighbor for a visit. It was raining, so we opted for indoor activities.
World Forestry Center
The World Forestry Center is next to the Oregon Zoo, and it was a dry place to wait for our next stop to open. It turns out that it is a children’s museum. A new exhibit had just opened so we toured Siberia by train, China by boat, the Amazon by a tree-top crane, and…
South Africa in a 1960s International Harvester Scout. I was ready to go, but the engine wouldn’t start.
Someone left a 22 caliber rifle in this tree back in the 60s, and it became one with nature.
This fake evergreen tree extends to the ceiling in the middle of the World Forestry Center. There were lots of activities for children of all ages, so this is probably a good place to visit with the family.
Japanese-American Museum of Oregon
After discovering forestry around the world, we went to the museum.
JAMO is small, but very interesting.
The early Japanese immigrants lived much like the Chinese, whose accommodations we saw in a previous post. By the 1930s they had established themselves throughout the West Coast, especially the PNW. This is a representative display of a general store.
There were dentists and all the trades because, despite being legal residents–many of them American citizens–they were prevented from fully participating in the American dream.
They lived in nice homes, owned businesses, spoke English better than most of their fellow citizens, but…
There weren’t enough of them to overwhelm the government’s demographers (unlike the German and Italian Americans), so they were rounded up in a show of national security; they were shipped to places where, if they were lucky, they shared a room like this with their entire family.
The JAMO has a lot of documents to read, but I focused on physical objects because I forgot my “museum glasses”, which focus at six feet. You’ll need to visit the museum yourself to learn the true history of the Japanese-Americans.
One brave activist violated curfew after release from a detention center, and found himself in jail for nine months. He eventually won in the courts, but at a high personal cost.
This terrible injustice wasn’t as horrific as what was done to the Native Americans, but it was pretty bad. The U.S. government eventually apologized, in the 1990s, but that was little consolation to those Americans who lost everything during a period of national paranoia. Some of them actually received a few thousand dollars in reparations (I guess they used 1940s dollars, not adjusted for inflation).
Mount Saint Helens Revisited: Ape Cave
We made it to our destination (Fig. 2) and explored a rare lava tube at Mount Saint Helens. This lava was erupted 1900 years ago as part of the same sequence that destroyed the forest a short distance away.
A full discussion of this fascinating natural feature is available from Washington Department of Natural Resources.
Figure 1. This lava tube is a lot larger than the tree casts we described in the last post. This immense cavern, which is more than 2.5 miles long, was created when a single basaltic lava finger flowed over the landscape. The outer material cooled in the air and insulated the interior, like an oven, allowing the remaining lava to exit the end of the tube. This left a void to be filled by subsequent lava flows. According to the information displayed at the site, the entire eruption lasted about 100 days.
Figure 2. Ape Cave is presumably named after the first eruption sequence of Mount Saint Helens, dated about 40 Ka. I didn’t find an explanation for this confusion, but it might have something to do with the Bigfoot legend associated with Ape Canyon, not far away. At any rate, the lava tube is indicated by the square in (B).
This video captures the scale of one of the many chambers better than any image. My narration isn’t very technical.
Figure 3. These parallel ridges running along the bottom of the cave near its terminus are the remnant of the last flow to use this conduit to reach open air.
Figure 4. A block of basalt transported through this narrow passage became stuck where the walls of a previous flow almost meet, leaving it stranded. It looks like it partially melted into the walls, however.
Figure 5. This view of the ceiling reveals a joint pattern caused by cooling of the outer layer of lava. Several generations of fractures occur throughout the cave, created as individual flows cooled differentially.
Figure 6. This is the end of the tube as it exists today. Apparently, there is no modern opening; it probably collapsed during the last 1900 years.
Figure 7. As a retired sedimentologist, I immediately noticed the layer outlined by the dash lines. This looks like cross-bedding; the layer fills a depression below the line, and is truncated by an overlying flow. This is interesting because cross-bedding is associated with particles being transported by wind or water; how it appears in a lava flow is an intriguing problem–perhaps heavy minerals like pyroxenes and lighter plagioclase feldspar?
Figure 8. This is a good time to briefly explain how the ledges seen in Figs 1, 4, and 6, and the video, were formed.
Once the lava tube was created by cooling of the surface of the original flow, subsequent flows ran through, but didn’t fill, an insulated tube. Their surface was usually below the original ceiling. The coolest parts of this conduit would have been the sides (heat dissipates more quickly through older, cooler basalt than the superheated air above the lava river). Thus, ridges like these formed where the molten basalt hardened. Of course, these subsequent flows were of different volumes and the rules of stratigraphy cannot be applied. Geologists have worked out these relationships but that is beyond the scope of this report.
Let’s just say that many rivers of magma flowed through this channel, like stormwater through a sewer pipe–some larger than others.
Figure 9. This is an enigmatic photograph because I don’t remember which wall it was on. I didn’t notice the detail when I took the photo, and now I can’t say if this is an excellent example of cross-bedding (always tilts downstream) as in Fig. 7. or a total mystery. My only excuse is that it was TOTALLY BLACK in the cave and I was disoriented the entire time.
Figure 10. We made it out without spraining an ankle or hitting our heads. This cave-in is the only entrance/exit for the downstream part of the tube. There is another one 1.5 miles upstream, but that route is difficult (according to the park information).
Final Thoughts
The Ape Cave lava tube, and the missing forest from my previous post, are part of the Spirit Lake eruption phase of Mount Saint Helens, which began about 1900 years ago and continues to this day. The magma chamber didn’t erupt at the center of the stratovolcano, but instead found an opening along one of the many cracks in the thick pile of volcanic rock that had accumulated during at least 50 million years.
Lava tubes present a unique eruption environment. Ground water that finds its way into the magma chamber cannot escape, thus pressurizing the conduit and altering the lava’s behavior. Imagine lava as thin as water surging through this passage, sloshing around, encountering obstacles, rushing headlong downhill towards what apparently was a small opening, if Fig. 6 is any indication of the narrowing channel.
It was a great drive through a wild terrain to reach Mount Saint Helens, and the destination was worth the effort.
Mount Saint Helens Revisited: A Missing Forest
My last post reported on Miocene (23-5.3 Ma) volcanic rocks on the eastern flank of Mount Saint Helens. Those rocks predate the creation of Mt St Helens, however; we reached our destination and, before exploring a lava tube called Ape Cave, we examined some interesting geology that is part of the most recent eruptive stage of this active stratovolcano. The Spirit Lake stage began about 4500 years ago. There were three earlier stages, beginning about 40,000 years ago; each lasted less than 5000 years.
Figure 1. About 1900 years ago, a large amount of basalt lava flowed from a fissure on the south flank of the volcano (indicated by a square in the inset map of Fig. 2). The lava was hot (~1200 C or 2200 F) and set the forest on fire; when the wood had been turned to charcoal, the lava cooled to leave casts of the trees. My wife is taking a photo of a small-diameter tube we’ll examine it more closely below.
Figure 2. Mount Saint Helens is about 70 miles south of Tacoma (Home in the right map), but the route we followed, around the north and east flanks, takes 3.5 hours to drive. The yellow areas in the inset map are mostly andesite lava flows older than 5 Ma. The circle is where we looked at them in the last post.
Figure 3. These holes were everywhere, forming a hazard for people walking, so a walkway was constructed over the area where the tree holes are densest. They haven’t been cleaned out and most are 3-4 feet deep.
Figure 4. This is the cast of a fallen log. The entrance is shown in Fig. 1; visitors are encouraged to crawl through it, about 40 feet, but it was too tight for us. However, several children I met there had braved the dark, tight tunnel.
Figure 5. This photo was taken a couple-hundred yards from the missing forest. The background reveals the leading edge of a lava flow that’s about ten-feet high. The foreground shows a stream being incised into the landscape, probably created along a collapsed lava tube. Regrowth of the forest is slow in the lava surface; however, there was no mention of whether or not this area was logged in the last century–it probably was, given the documented greed of the forest industry when it came to cutting down trees. However, I didn’t see any large stumps, so maybe it wasn’t worth the effort.
Figure 6. This is a mound of lava projecting up to 8 feet above the surrounding landscape. Several features are worth mentioning: 1) it is circular in plan and about 30 feet in diameter; 2) the upper-center of the image shows concentric bands of ropy lava known as pahoehoe, from its common occurrence in Hawaii; and 3) there is a small cave beneath it where lava ran out of the hardened surface. We’ll see a lot more of that in my next post.
Final Thoughts
Our journey along the backroads took us through a vast terrane of andesitic volcanism created more than five-million years ago. Then, about forty-thousand years ago, a new phase of volcanism began and Mount Saint Helens was created from this rugged ground.
Stratovolcanoes don’t just erupt at their summit, even though that is exactly what Mt St Helens did in 1980; more often they leak lava from the myriad faults and fissures surrounding them, especially in an active subduction zone where the earth’s crust is being compressed, twisted, and warped by tectonic forces.
Life is difficult in such an environment and we are fortunate to have a moment in time frozen for us to contemplate how immense the forces are that constantly reform the surface. Eruptions like the one that destroyed this forest are unlikely to kill many people, but they are crucial in reforming the environment. A new forest grows, possibly inhabited by different species of fauna and flora, and life goes on.
My next post will examine this same eruption event, but at a scale that dwarfs what we saw today.
Wing Luke Museum: A Guided Tour of an Immigrant Hotel
Wing Luke was a pioneering Chinese American lawyer, civil rights advocate, and the first Asian American elected to public office in Washington State. When he died in a small aircraft accident in 1965, the community formed the Wing Luke Museum in his honor. It celebrates Asian-American history and culture, and owns a hotel it purchased to display the lives of early immigrants.
The Yick Fung Corporation was formed by a group of Chinese immigrants because they were legally forbidden from owning property in Washington. This store served as a supplier to restaurants throughout Washington.
South Weller Street led directly to the tidal flats where the church steeple stands today. As part of a downtown reshaping, several hills were flattened and the soil used to fill in the nearshore area.
In addition to supplying regional restaurants, you could buy a third-class ticket to Hong Kong (or maybe Shanghai) for $1500 in today’s money. The store remained open until 2008.
To circumvent some of the financial restrictions, the Chinese immigrants formed associations of people from the same villages back in China. This is the meeting room of one such group. They assisted newcomers and planned civic activities. It was kind of like the YMCA.
This is the game room, where people played mahjong and other games.
The hotel contained about 180 apartments, but some of them had up to three rooms. This was the home of a family with eight children. The hotel remained a center of immigrants until it was closed in 1974 because of updated fire codes (after the deaths of twenty or so inhabitants in about 1972). The Wing Luke Museum purchased it and is renovating it as part of the display.
Every room was required to have a door and window. Most of the rooms were small. That is the light shaft out the window; it didn’t lead anywhere and only extended to the second floor, just for light and air.
Living out of your suitcase?
Here’s the light shaft. During reconstruction the building was modified and reinforced.
The museum also had exhibits displaying artwork and pictorial histories of many Asian immigrants, including Hawaiians. Overall, it was very interesting and worth the price of admission. I think it was $22 for a senior like me.
Geologic Survey of Eastern Vancouver Island, British Columbia
Figure 1. View looking west along the coast from Beacon Hill, in Victoria. The cliffs on Vancouver Island are similar in height to those across Juan de Fuca Strait, in Washington. However, the bluffs are composed of glacial deposits further south in Seattle, rather than bedrock. The large tidal range (7-10 feet) exposes rocky platforms at low tide. I’ll examine several of these features in this post.
Introduction
Figure 2. We drove to Port Angeles on the Olympic Peninsula and took a ferry to Victoria. We also drove about 70 miles west to Port Renfrew. The inset geologic map reveals a maze of faults and rock types. The rocks around Victoria comprise the Westcoast Crystalline Complex, which includes granitic and metamorphic rocks dated between 540 and 143 Ma (colored green). The purple area indicates a suite of granitic intrusions from the Jurassic period (200-160 Ma). The numbers indicate locations discussed below: (1) Beacon Hill; (2) Mount Douglas; and (3) Port Renfrew.
Beacon Hill
Figure 3. This exposure of the Westcoast Crystalline Complex at Beacon Hill Park doesn’t tell us much. These rocks are weathered and stained, making identification difficult without breaking off a fresh piece. We don’t do that here at Rocks and (no) Roads. Nevertheless, I am relatively confident that they are not sedimentary rocks.
Figure 4. This photo uses a magnification of 10x, and the field of view is less than an inch. Individual crystals of feldspar can be seen throughout the image, recognizable by flat surfaces that form irregular boxes. These light-colored feldspars are indicative of continental intrusive rocks like you would find in a subduction tectonic environment. The gray blobs are quartz. Based on this brief examination, I think these are granodiorite, an intrusive rock rather than metamorphic.
Mount Douglas
Figure 5. The view, looking south from the top of Mount Douglas (see Fig. 2 for location), reveals Mount Olympus (snow-covered peaks in the distance); and intrusive rocks with the characteristic salt-and-pepper color of granodiorite. This exposure also contains a set of joints (large X pattern enhanced by weathering) that would have appeared as the rock rose through the crust as overlying rocks were eroded. Victoria is visible in the distance.
Figure 6. This image shows veins of quartz or feldspar (white material) that would have filled cracks and voids after the main magma had solidified (tens of miles deep), but residual liquids were still present.
Port Renfrew
Figure 7. The cliffs at Port Renfrew are lower than in Victoria (compare to Fig. 1). They also don’t appear to be the same intrusive rocks we saw at Beacon Hill Park or Mount Douglas. The beach is covered with boulders and dark, coarse sand that couldn’t have originated from the erosion of granitic rocks. Let’s take a closer look.
Figure 8. (A) This boulder includes a piece of the rock the magma was intruded into. The rounded edges suggest that the magma was still hot enough to partially melt the fragment; furthermore, the lack of a halo surrounding the inclusion implies that the melted material was incorporated into the magma by mixing. (B) This looks a lot like the granitic rocks in Fig. 5. (C) This boulder is fresh and individual minerals can be identified. Being wet enhances the contrast. The low quartz composition (I estimate it at ~20% from the gray blobs) suggests that this is either granodiorite or tonalite, depending on the amount of Ca-bearing feldspar. That requires either a chemical or mineralogical analysis. These boulders were transported along rivers from the center of the island, which is composed of granitic rocks (Fig. 2).
Figure 9. These ripples are almost a foot long, measured from crest to crest; and the troughs are filled with larger fragments of rock and shell. You don’t see these sedimentary structures preserved in the rock record very often, even if they do survive the vigorous tides on Vancouver Island.
Figure 10. Exposures like this make geology fun. The darker rocks are tilted about 30 degrees to the left, but there are two distinct rocks types here: the lighter colored rock to the left is the same sandstone that makes up the cliff (Fig. 7); and the darker rock is schist, highly altered mudstone. In other words, a mildly altered rock is in direct contact with a metamorphic rock.
I checked with RockD, which integrates a global geologic map with location, and discovered I was standing on the contact between Leech River Complex metamorphic rocks (200-66 Ma) and Carmanah Group unaltered sedimentary rocks (37-23 Ma). This is a textbook unconformity that represents at least 29 million years.
The younger rocks are nearly horizontal, so I think this is an angular unconformity. During the missing millions of years, the older sediments were buried and heated enough to create schist; then uplifted and exposed to the sea, whereupon the younger rocks were deposited on a beach not that different from what we see today.
Figure 11. The devil is in the details, as shown in these images. (A) The older rock was folded during burial and, when exposed to the waves, eroded along relict bedding surfaces. Coastal sediments were then deposited in nooks and crannies like we see today. (B) Those dark fragments that look like they’re lying on the beach are actually cemented in place; the background pebbles aren’t modern sand, but instead sand frozen in time at least 29 million years ago.
Amazing.
Summary
Sometimes you can tell a story about the rocks you find, and this is one of those times. And it’s a story that unfolds across the globe. However, this story can’t be easily told because it unfolds on a sphere–the Earth. I’ll do my best.
For hundreds of millions of years, way back in the Paleozoic era, what we now call North America was drifting eastward and the West Coast (e.g. the Pacific Northwest) was a passive margin, like the East Coast is today. Suddenly, geologically speaking, the supercontinent, Pangea, which had been created from all the continents, split apart. North America reversed direction and the passive margin became a collisional plate boundary.
Ocean crust, and any islands or microcontinents that were in the way, were swallowed by the mantle or crushed by North America, creating the igneous rocks we saw at Beacon Hill Park and Mount Douglas. Muddy ocean sediments were swallowed and transformed into the schist we found at Port Renfrew. Volcanoes erupted all along the West Coast.
Then the story gets complicated and controversial.
Because the earth is not flat, crustal plates don’t slide beneath one another like sheets of paper. They crumple at the edges, forming transform faults (e.g. San Andreas fault of California) along which tectonic plates (or pieces of them) can slide past each other horizontally. This probably occurred between 200 and 66 million-years ago; if so, the rocks of Vancouver Island were originally deposited/intruded in Eastern Washington before sliding hundreds of miles to the NW.
When the crumpled edges of the colliding plates had taken up the slack, subduction resumed to the SE and the Cascades Range of volcanoes was born. This process continues to this day.
That’s the best story I’ve heard so far.
Three Days on Vancouver Island
If you’re ever in the PNW, you can drive to Vancouver Island on the M.V. Coho, a ferry commissioned in 1959, which plies the route from Port Angeles, Washington, to a berth in downtown Victoria several times a day. Victoria is the capital of British Columbia–that’s a province in Canada. In this post, I hope to show you how much there is to explore without venturing into the wilds of an island that is more than 280 miles long.
This is going to be a long post because the culture and geography are so intertwined that they cannot be experienced, much less discussed, in isolation. However, I will present my geological survey in a separate post.
Let’s do it!
Downtown Victoria
We stayed a couple of blocks from the waterfront, where British Columbia’s legislature meets (Victoria is the capital). On this particular weekend, which had spectacular weather, there was a free concert on the waterfront for David Foster, a Canadian music writer, publisher, etc, who comes from Victoria. They had a massive celebration, with Jay Leno as MC, beginning with an aerial display by the Snowbirds–the national aerobatics flying team–and ending with a fireworks display that lasted 30 minutes.
You can catch a tour in either a single- or twin-engine seaplane. They take off and land right in the harbor. That’s crazy, but somehow they don’t have enough incidents between aircraft and boats (including cruise ships), to make the news. I checked.
This is one of the most interesting waterfronts I’ve visited, probably because it is summer; however, Vancouver Island has the warmest overall climate in Canada. Food for thought.
Beacon Hill Park
We like to walk, so we strolled towards the coast and discovered beautiful gardens and some of the bedrock exposed, with steps leading up to it; but this isn’t Beacon Hill proper.
Beacon Hill Park is occupied by a flock of Indian peafowl (Pavo cristatus), which apparently are okay with the mild winters in the PNW.
From Beacon Hill itself, you can see Mount Olympus (about 8000 feet elevation) across Juan de Fuca Strait. It is the snow-covered mountain, only forty-six miles distant.
Royal British Columbia Museum
The museum had a display of Egyptian artifacts focused on death and the afterlife, but you can see something like that almost anywhere…
My favorite exhibit was an incredibly detailed recreation of life in Victoria about 100 years ago, which showed how the island evolved through the twentieth century. As an aside, I have a license to drive that Ford Model T, but that’s another story.
Craigdarroch Castle
This luxurious estate (originally 28 acres) was built on a hill overlooking Victoria in the early 1900s by a coal baron, who didn’t live to occupy it. But his wife and children did. It served as a military hospital during WWI, which saw more than 200 thousand Canadian casualties. That’s a lot for a smaller country; those with long-term disabilities were sent to recuperate in places like this. The property fell into disrepair after the war, the property was divided into parcels for the surrounding homes, and eventually purchased by a non-profit society, who is restoring it to its original condition.
The interior is an eye-catching, and confusing, 4.5 floors of engraved wood and paneling, even the ceilings. The carpentry was completed by a Chicago company that had worked on several other mansions.
I’m sure that Robert Dunsmuir (the builder) would have enjoyed this oversized pool table. But the balls seem a little small–I guess it wasn’t for regulation play. The entire house was decorated to this detail.
Dinner is served. The kitchen has also been restored and tourists are encouraged to handle the stove and other appliances, but I wanted to keep this post as short as possible. LOL!
Port Renfrew
We finally used our car to drive the 68 miles to Port Renfrew. I don’t know why it’s called a port because it is a temperate rainforest with a few inhabitants, mostly catering to ecotourists. Obviously, this is not old-growth like Olympic National Park in Washington, but it’s working hard and fast to recover. We walked for a mile BENEATH a dense growth of ground cover, which had assumed monumental proportions. Surreal.
The tidal range is 7-10 feet, so a vast intertidal area exposes rock (I’ll address that in a later post) and a huge number of tidal pools, hosting a myriad of sea creatures.
I took this photo in a tide pool scoured in sandstone, about two-feet across and one foot deep. According to ChatGPT the circular animals are sea anemones whereas the shiny critter is some kind of chiton (a distant cousin of snails and clams). While I was studying the rocks, everyone else was staring into the huge number of tidal pools scoured into soft rock, each a tiny world that is never dry because the tide comes in twice a day.
The Butchart Gardens
This incredible garden was constructed in and around an abandoned limestone quarry, by the owner of a concrete company–kind of like the castle built by a coal baron. They had a vision and a plan, which included international experts and a commitment by their children. This is the sunken garden. The meticulous care given this floral extravaganza was displayed by workers pulling weeds by hand, and dead-heading the flower in full public view–well worth the 46 Canadian dollar price of entry. No senior discount.
This display cannot be adequately shown in a video. The “pond” running through the sunken garden is 40 feet deep and pristine–and I mean PRISTINE. Ferns and other climbing plants were meticulously planted in cracks in the limestone walls of the quarry. It ain’t a quarry anymore.
Butchart Gardens is more like an amusement park than a flower garden. Among the specialty gardens, I recall a Japanese garden with streams running throughout, the soft murmur of water encouraging me to take a seat on one of the many benches. There was a rose garden, with every plant labeled. An Italian garden. The topiary displayed in this photo was evident everywhere it was appropriate. And plenty of coffee bars…and washrooms (Canadian for toilet).
Mount Douglas Park
The sign welcoming us to Mount Douglas doesn’t say anything about blue trails or black trails. We learned about that when we climbed (not hiked) 600 feet in less than a mile–very similar to Piestewa Peak in Phoenix. By the time we found ourselves on a ledge overlooking Victoria, we figured out why the lettering was black on this trail.
It was a little scary, like riding The Hulk at Universal Studios the first time, but it was invigorating; neither of us got light-headed, except from the view…
That is Washington across Juan de Fuca Straight. The low cloud bank covers the water between the U.S. and Canada. Snow-covered Mount Olympus can be seen in the distance.
Looking east from the summit reveals a suburban landscape rather than a metropolis because Victoria’s downtown is north of Mount Douglas.
It was a busier day at sea on our return to Port Angeles. We saw two container ships, one smallish and one large, half-filled one, and this vessel. It was several miles from our ferry when I took this pixelated image, but ChatGPT identified it as probably the Seaspan Lions, an LNG bunker vessel; this is a new class that transfers liquified natural gas to larger, oceangoing vessels from Vancouver or other Canadian ports. I mention this because I’m fascinated by technology (real tech, not digital bullshit). These smaller vessels transport LNG from ports too small to accommodate large vessels, which are three times as long and ten times as heavy.
Final Thoughts
What a ride!
If you ever take a cruise to Alaska to see the glaciers, or even a cruise to Hawaii during the off season, take a couple of days to experience Vancouver Island. Despite being the capital of British Columbia, the only contact with North America is by boat, even from the city of Vancouver–British Columbia geographic names are confusing.
The best thing about this trip was that we never felt like we’d left home. Victoria feels like Washington, and even The United States in general. They don’t have the humorous Canadian accents I’ve seen on TV. They drive the same cars, shop in the same stores, and even go to the washroom–just like I did, growing up in Arizona in the 60s and 70s.
Best short vacation EVER!
Flaming Geyser State Park
The park is located at the upstream end of Green River, where it enters a gorge. This is one of the best places I’ve seen anywhere for taking a stroll through nature; the path is moist but not muddy, and well trimmed, with breathtaking natural scenes like this. A veritable Garden of Eden. This post is an overview of the park; I discuss the geology and flora in other posts.
With a name like that, I’m expecting a spectacular show…
I’ll summarize what you can read if you zoom in on the information presented in this billboard. An exploratory well was drilled here about 100 year ago, looking for coal–they found it, along with methane (natural gas) and other gases produced by decaying vegetation at several hundred feet below the surface. The small well produced a flammable gas that has burned intermittently since it was first lit by a geologist.
Flaming geyser wasn’t very active when we visited, but it was burning. To repeat, this is NOT a natural seep, but the result of a well drilled a century ago. Nevertheless it has become a local tradition, and it is relit whenever it goes out.
Bubbling geyser is a lot more fun. This video shows small bubbles of methane, as well as hydrogen sulfide and other, unnamed, gases. Methane is odorless, but this area smelled strongly of H2S, which is added to natural gas to help detect leaks.
This is a beautiful example of survival. The surface roots have all been exposed by erosion, but the tree is thriving; its roots have turned into separate trunks. I read somewhere that these conifers in the PNW send their roots out for hundreds of feet, far beyond their canopies.
This is where Green River Valley turns into Green River Gorge. The water was perfectly clear, with a slight green tinge, even though there is no algae visible. It reminds me of Commencement Bay, which is also devoid of aquatic plants. And it is all natural, simply a unique ecosystem.
If you wear waders, you can walk on water here.
Final Thoughts
This is a place you have to visit for yourself, especially on such a gorgeous summer day. The temperature was in the mid-seventies, the sky was clear, and people were filling the huge number of picnic areas, carrying their supplies and tubes, ready for a fun day of floating down one of the best rivers I’ve ever seen.
You’ve got to see it for yourself.
The Foothills Trail along Carbon River, Pierce County, Washington
This post is a humorous (I hope) addendum to my posts on the geology and flora of Carbon River. I have noticed a lot of quirky, regional trends, both in decoration and signage, here in the Pacific Northwest (PNW) during our nature walks. The Foothills Trail was no exception.
There are several access points to the trail, but this was the only sign. It ends with a serious warning: Use at your own risk. What lies ahead in that darkness?
A couple miles downstream from the “official” trailhead, we stopped along the Carbon River. This is a piece of ubiquitous columnar andesite that was apparently placed here as a decorative piece. Unfortunately the sign is long gone.
The trail is wide and easy to access on foot. I don’t know about a wheel chair although it is flat all the way.
We saw several of these marker stakes along the trail. I looked it up and, to the best of my knowledge, this is indicating a tree where a pair of Marbled Murrelets are nesting. They are an endangered species and extremely difficult to locate, but there is an ongoing survey program. That sounds reasonable to me; the sign gives both a distance and compass heading to the tree.
The trail intersected the Franklin Bridge, which is indefinitely closed to traffic.
We climbed a steep slope, with the help of sturdy handles attached to wire rope, and took some photos on the bridge.
After we finished on the bridge, we passed the concrete blocks obstructing the road. Several signs made it clear that the bridge is closed to cars, bicycles, and pedestrians. Apparently someone disagreed with the DOT restrictions, and modified the sign. Don’t ask me why the figure is carrying a gas can that says, “Oh ya fuck ya.” I guess they’re thumbing their nose at anyone who would dare condemn what looks like a perfectly useful bridge — at least for people and wild animals.
We walked the three miles back to our car along the abandoned road. There were several rock falls and damage to the guardrails. In this image, a large boulder smashed through the eroded roadbed. It was like a post-apocalypse movie. Pretty cool … and quiet.
These relatively new signs were posted randomly on trees on the hill of the road. Hazards. Not hazard. Maybe Western Rattlesnakes, poison ivy or … dare I say it? Bigfoot. Stay out of the woods. But we just walked three miles through the woods. Damn!
These opposite-pointing signs were on a curve. Nevertheless, I have to wonder why the guardrail stops in the middle of the curve, but reflective signs were felt necessary. Short sightedness? Budget constraints? Stupidity?
The Flora of Carbon River, Pierce County, Washington
Plate 1. Our first stop was at Carbonado, where the Carbon River exits the canyon that has constrained it from its origin on Mt. Rainier. It immediately forms multiple channels as it cuts through glacial till on its circuitous path to Commencement Bay.
Plate 2. This lovely flower is red clover (Trifolium pratense), a common wildflower along rivers.
Plate 3. CoPilot and I argued too long about this one, but, after some back and forth, I decided it might be a genus of Spiraea. They are another common shrub in this ecosystem, but they aren’t in flower in July. Note the shriveled flowers in the right image. Too late to be sure. That’s why I’ve always ignored these bushes.
Plate 4. Cow parsnip (Heracleum maximus) is a common wildflower in meadows and roadsides in Washington.
Plate 5. Tansy (Tanacetum vulgare) is a common wildflower along the Carbon River corridor.
Plate 6. I thought, when putting this post together, that this was red clover (Plate 2), but CoPilot identified it as Canada thistle (Cirsium arvense). It loves disturbed areas like river edges. I did detect some spines when I zoomed in on the second photo. Why am I not surprised? If it’s pretty it will have spikes ready to draw blood from any inquisitive passers by.
Plate 7. This view is looking downriver from Franklin bridge, which is permanently closed. I’ll now describe some of the flora we encountered as we followed the river along a steep slope.
Plate 8. I (kinda) got this one right. This is a wild rose, Nootka rose (Rosa nutkana). This is another plant that waits for an opening in the forest canopy to grow, and then it colonizes like crazy — until the forest canopy catches up with it. Moist but well-drained soil pretty much sums up Carbon River canyon.
Plate 9. This familiar flower is foxglove (Digitalis purpurea), introduced from Europe; but it is so naturalized that it behaves like a native plant, similar to Cascade penstemon (see Plate 11), thriving in disturbed ground at the edge of conifer forests and in temporarily sunny areas.
Plate 10. Besides white flowers, I am also fixated on thorns; however, I don’t know anything about thorns except that roses have them, as well as many of the shrubs I’ve encountered on my nature walks. This is probably Himalayan blackberry (Rubus armeniacus), an invasive species to Pierce County. I guess that’s why it isn’t called Washington blackberry, or some such. I checked a previous post from Point Defiance, and there it was! Invasion of the forest snatchers.
Plate 11. This purple wildflower is probably Cascade penstemon (Penstemon serrulatus), a native to the PNW. It is what CoPilot calls an ecotone plant — one that thrives where a conifer forest is encroaching on a prairie environment. We encountered it where the conifers hadn’t yet blocked out the sun along the trail.
Plate 12. I’m easily fooled by white flowers. This non-woody shrub is False Solomon’s seal (Maianthemum racemosum). It grows in the understory of a conifer forest, which is a good description of Carbon River canyon.
Plate 13. This is the first triplet I’ve seen from a nurse log. These young hemlocks will certainly compete for sun and nutrients. There can be only one survivor.
Plate 14. I thought this was cow parsnip, but CoPilot identified it as ocean spray (Holodiscus discolor). The white flowers were all I needed to see, but this tall, woody shrub (6-12 feet) is completely different from the weed in Plate 4.
Final Thoughts
The only thing I can add to the photos is that Carbon River is part of a transitional ecosystem, not unlike Mima Mounds. I Imagine this borderland environment is also alternating between a lowland/prairie and an upland/conifer forest, depending on conditions. However, much to my disappointment, the plants here were different from those we saw before. Furthermore, there were far more species along the Carbon River corridor. We were fortunate to visit when many of the flowers were in bloom.
I enjoy taking pictures of flora and learning about the ecosystem, but this is too complex for me. I’m only a simple geologist.
Mima Mounds Natural Area Preserve
It was unbelievably gorgeous weather here in the Pacific Northwest (PNW), with a high of 74 F, so we took a look at a couple of nearby natural areas.
Mima Mounds
This exceptional area isn’t unique but it is an unsolved geological problem. It is also peculiar in being a transition zone between active prairie and forest ecosystems. I’ll try to explain this with photos, and some help from CoPilot, Microsoft’s version of ChatGPT. However, I won’t solve the geological conundrum, which may never be fully explained.
The Mima Mounds are about 16500 years old. They formed as the last continental ice sheet retreated from Washington. The mounds you see in this photo sit atop a gravel surface created at the southern extremity of this glacier. People, including the native Americans who have lived here for tens of thousands of years, have been perplexed by this bizarre topography.
There is a 1.9 mile trail that goes through the area; however, when European Americans first came here, this topography extended for more than twenty miles. Most of it has been demolished.
This is a portion of the information board at the interpretive center. (A) The Mima Mounds were constructed after the ice sheets began to retreat for the last time. The inset map shows the location of the NAP relative to the glacier and modern cities. This was the absolute furthest south of thick ice, but that doesn’t mean it was warm. (B) This is a rare photo of a cross-section through a mound. The dark soil is organic-rich and excellent potting soil. The subjacent glacial outwash is gravel. (C) This is a photo from the air, which shows their regular spacing. This is the geological problem. How could they have formed over about 400 square miles?
There are many theories for the origin of the Mima Mounds, and other mounds found in N. America and elsewhere. These are summarized on the Wikipedia page. I included this photo because it was on the poster; and the size/shape of these blocks of permafrost from Scandinavia are a good match to the mounds we saw. And they are in a similar, post-glacial environment.
Prairie Ecosystem
I’m discussing both the geology and ecology of Mima Mounds together in this post because they are inextricably connected. There are two ecosystems competing for space in this lumpy prairie environment. The result is there for anyone to see, if they ask the right questions.
This low shrub was identified by CoPilot as snowberry, which is a staple of the prairie. I only saw them on the mounds, their roots in good soil, but apparently they also do well in the sandy glacial soil. From my perusal of the internet, I can’t disagree.
My ignorance is hilarious. I thought this was some kind of wildflower … but CoPilot identified it as a Douglas fir seedling. They were growing only on the mounds, sometimes in clusters. This is evidence (to me and CoPilot) that this is a dynamic transitional environment where forest species coexist with prairie flora.
This fern caught my eye because it is not a natural inhabitant of a prairie ecosystem. However, the mounds are near a forest, so … CoPilot thinks it is a bracken fern, which is native to the area but not a prairie environment. It often behaves as an aggressive colonizer in disturbed edge habitats. That last phrase gets my attention because this preserve is at the edge of a mature forest.
This lovely flowering shrub was identified by CoPilot as a species of Lotus, commonly called Spanish Clover, deervetch, or trefoil. It grew in the sandy areas between the mounds. My quick check can neither confirm nor deny this identification, but this common variety of clover is native to the PNW.
This mound is populated by bracken ferns, crowding onto the area with good soil.
I don’t know what species this copse of young trees is, but it is obviously encroaching on the prairie ecosystem.
You never know what you’re going to find when you go outdoors. According to CoPilot, this is probably the result of NAP’s policy of not removing human artifacts that don’t interfere with the environment. Manpower shortages, policy priorities, etc. Mima Mounds was established in 1976, so it’s fair to say that this structure is at least that old. I guess NAP hasn’t gotten around to it yet, which fits my nascent sense of priorities in the PNW.
Bill Frank Jr. Nisqually National Wildlife Refuge
We stopped for a quick visit, which turned into a one-mile death march (for me, after walking 4 miles on uneven ground), to see where the Nisqually River empties into Puget Sound. It originates from the face of an alpine glacier above 6000 feet on Mt. Rainier. This is a tributary stream that forms a series of algae-covered ponds.
Here we are, less than a mile from the Nisqually River’s delta in Puget Sound. There is a lot of downcutting and the creation of sand bars, but no boulders or even cobbles. This glacial river has been tamed by nature over a distance of about eighty miles, but it is still flowing pretty fast. We didn’t make it to the delta … maybe next time.
Summary
This was a great day trip to a fascinating and beautiful area, where the prairie and the forest compete for space on the top of mounds of top soil whose origin is a mystery. This back-and-forth movement of plants on timescales of years to decades suggests that the PNW is alive and well, the flora responding to minute changes in soil and air temperature/moisture, precipitation, wind, etc. Let’s hope these two thriving ecosystems can continue their dance without further human interference.
I have my own hypothesis about the formation of the Mima Mounds, which is consistent with the facts. 1) As the glacier melted and retreated, over thousands of years, shallow lakes developed in local depressions. These lakes were shallow, perhaps twenty feet deep, and limited in extent. 2) Fine-grained sediment (i.e. mud) and organic debris settled in them to depths of no more than ten feet. They were ice covered for part of the year. 3) As the glacier retreated further, streams began to superimpose their beds onto this landscape, but they weren’t like a glacial river (e.g. Nisqually River). These were weak streams flowing over a post-glacial landscape, meandering and not cutting new channels. 4) This mild erosion was superimposed on a landscape dominated (in this area) by an antecedent pattern like that seen in the Arctic (see above photo). Fine-grained sediment was removed, following a suture pattern until only irregular bumps remained. 5) This process of sheet-flow erosion continued to the present day, leaving us with these paradoxical mounds.
I am a sedimentologist, so I think in terms of turbulence and flow as interconnected processes that alter a landscape slowly, one grain of sand at a time. There wasn’t enough turbulence to strip away the veneer of clay over this basin in the time allowed, so it chipped away at the weak edges of lumps of soil that were probably held together by the roots of plants.
In other words, the thawing of permafrost created the pattern, and turbulent flow polished it to what we see today.
Prove me wrong…
Timothy R. Keen 
Recent Comments