Sunday, January 29, 2012

San Juan Islands

In a previous series of posts I mentioned that for the Rodeo Holidays we went to Mt. Baker after being at the San Juan Islands. We did not spend long on the San Juan, but we did get a flavor for the area. The day started with a stop at Deception Pass State Park. The park encompasses both sides of the channel that forms between Fidalgo Island and Widbey Island and the Iconic bridge that joins the two island.

Deception Pass connects the Straits of Juan de Fuca and Skagit Bay, and during the change in tides, the difference in response rate between the Bay and the Strait cause a visible current through the pass, sometimes resulting in standing waves and whirlpools. We came through just as the tide was turning so we were able to see the current, but not the large standing waves.

From Anacortes (just north of Deception Pass), we took the ferry to the San Juan Islands. The San Juan Islands consist of an archipelago that represents a submerged mountain range that connects Vancouver Island with the mainland. The Islands are largely composed of Paleozoic aged sedimentary rocks which have been folded into a broad east/southeast plunging syncline. The sedimentary rocks have been intruded and metamorphosed by Mesozoic aged igneous activity. During the Pleistocene, the mountains were heavily glaciated so many of the straits and channels have fjord like characteristics.

Within the Paleozoic aged sedimentary rocks are lenses of Devonian aged limestone. These limestone deposits are accessible on San Juan Island near Roche Harbor and at Lime Kiln Point on San Juan Island. In fact Roche Harbor was a company town dedicated to the production of Lime, and much of the historic town infrastructure has been retained by the resort that now owns the town.

Lime was produced from the Limestone at Roche Harbor and (what is now) Lime Kiln State Park beginning in 18608. Some of the old lime furnaces are still standing, including this one at Lime Kiln State Park (built in 1918).

1918 Vintage Lime Furnace
According to the informational sign located at the site, typically two loads of lime were produced each day by dropping softball sized chunks of limestone in a hole at the top at the top of the furnace.

Limestone chunks into a hole at top
3 1/2 loads cords of wood per load were into the sides to keep the furnace temperature near 1100 degrees C.
Wood added on the side
The heat removed the CO2 leaving behind powdered lime (CaO) that fell through a screen in the furnace. The lime was scraped from the furnace into barrels (100 per load) and shipped by sea to Roche Harbor where it was then sent to Seattle and beyond.

Finished Lime out here
Lime production continued from the San Juan's until 1923. Although the limestone was high quality for producing lime, the fact that lime explodes on contact with water meant shipping lime from the San Juans was hazardous, eventually lower quality limestone deposits inland that could be shipped by rail became more economical and the lime business in the San Juans ended.

Sunday, January 22, 2012

Fort Rock

On the way home from Crater Lake, we drove through Southern Oregon. My primary purpose was to stop at Fort Rock State Natural Area.

Fort Rock is a volcanic tuff ring that stands about 200 feet above the surrounding paleolake bed. It is a near circular ring of lapilli tuff that is the result of a Surtseyan eruption 50-100 ka. Most of the larger clasts in the tuff are welded glasses and pumice

But in some places small basalt bombs are included too

Subsequent weathering by wave action created an opening on the south side of the ring, so you can hike inside the ~1 mile wide crater. Where the waves interacted with the structure, along the outside and along the cut, there is a visible bench. At other tuff rings in the area, these benches show evidence of human habitation 9-10 ka
Bench on edge of Opening
After Fort Rock, we cruised through the desert high plains of the Christmas Valley and into Burns, where we turned north to home. We were all ready to be home, so we didn't stop to geologize along the way, just a reason to go back and explore again.

Monday, January 16, 2012

Utah Museum of Natural History

We went to Salt Lake City to visit Sam's grandparents over the Christmas holidays. They informed us that the Utah Museum of Natural History at the University of Utah history had moved into a brand new space. We make it a habit to visit natural history museums, and from my time at the UofU, the Utah museum has always been one of my favorite.

The major corporate donor for the new building was Rio Tinto, so the building had a beautiful copper sheeting and a great location up on the "benches" right next to Red Butte Gardens.
It was clear that much of the emphasis in the new facility was highlighting the extensive collection of dinosaurs. The building was designed for museum gowers to enter directly into the hall of dinosaurs, and snake their way through (most of) the rest of the exhibits. (We ended up missing the space science and formation of the planet exhibits because they were on another floor and unconnected. Only when I looked at the map as we were leaving did I realize we had missed it.)

I really appreciate it when you can get a scale for how big some of these creatures were. This picture of the sauropod was taken from the balcony overlooking the dinosaur area. It was my best attempt at getting the whole of the skeleton in the field of view of the camera.

This picture was a little closer up, and uses Sam as scale for the hind foot of the Sauropod. The perspective is a little off because of the distances, but the total ground to hip distance is a little over 3 meters.

Utah his famous for it Jurassic aged dinosaurs, but I didn't know there were Cretaceous aged fossils too. The museum also had a small room (and map) with some of the Cretaceous dinosaurs found in the state.

There was also a cast of the skull of a T. Rex (I think Big Al). I remember this cast from the museum when it was at the previous location, and it is certainly an impressive piece. My only real critisicm is that it is in a display case of Cretaceous aged fossils found in Utah, and it is suggestive that it is a Utah fossil (to be fair, the tag identifying it says T. Rex skull from Montana, but I still found it misleading).

One of my favorite displays, and one that certainly highlights the advantage of a new bigger space, was a wall with a cladogram showing different ceratopsin skulls.
The remodel also updated many of the informational signs. They were much more colorful and had good interpretive content.

From the hall of dinosaurs, the meandering path went to an area on the ecosystems (past and present) of the Lake Bonneville and the Great Salt Lake. It was a nice display. but it seemed a little out of context. Also, I spent a good amount of time looking for a display, or information about the draining of Lake Bonneville through Red Rock Pass, but I never found it. Maybe because it happened in Idaho...

From the Salt Lake area, it was back into general geology and a discussion of the ecoregions of the Basin and Range Provincne. A nice diagram of the Rock Cycle

A somewhat crude, but interactive display where you got to pull apart a piece of plywood to see the formation of Basins and Ranges

 A seismograph from two (there was room for three) locations tracked by the University of Utah Seismograph station

Yellowstone Seismograph on Left, Little Cottonwood Canyon on Riight
The main hallway ended in the biology area, which certainly much updated and much improved from the 1960s vintage stuffed animal displays that the old museum had. But when I got here, I thought where were the minerals! The old museum had one of the best displays of minerals I had ever seen. You could have taught a whole segment on minerals to a intro geology class at the previous display. It was a spaceous display showing minerals by property (hardness, cleavage, mineral habit, luminesence, etc), by family (silicate, oxide, sulfide) etc, as well as displays minerals common to Utah. I LOVED the old display and figured with the new building it have updated displays.

I was disappointed to say the least. The new Mineral display was one tiny hallway, located out of the way, with only about 1/4 of the minerals on display and not with the same level of detail.

Some of the old displays had been moved, like the minerals that exhibit, flourescence
But most of the new displays just showed minerals, with their associated names.

In all, the new museum had a much nicer biology display, and the focus on dinosaurs was evident. But I was sadly dissapointed that the flow of the museum didn't always transition well from one area to the next. The museum nicely went through the first four floors, but then the space science and mineral displays were off the path and woud be easy to miss. But most of all I mourn the loss of what had been one of the most complete mineral displays (second in my mind only to the Smithsonian).

One final observation, on the day went Sam's Grandmother was in a wheelchair. I think every architect in the country should have to spend a week in a wheel chair before gettting a license. While the building was fully ADA compliant (and I would bet the old one wasn't), it was not very wheel chair friendly. Some of the ramps were out of the way, and many of the displays (specifically books of pressed plants for the Basin and Range ecozones) and placards were at a convient height for a standing adult (or over the head of someone in a wheel chair).

In all, it was still worth the visit, but it no longer is in my "top five"

Sunday, January 15, 2012

More Summer Trips

Ok, so its been a while since I have been able to sit down finish posting about our trips last summer. After our trip to Sumpter/John Day, we spent a week at the coast. Most of our time at the coast was spent playing in tide pools and seeing non-geology things, but I did take one picture of some barchan dunes on the beach below the Yaquina Bay Lighthouse.

On the trip back to the east side of the state, we took the scenic detour through the desert high plains. This allowed us a stop at Crater Lake, which Sam had been wanting to go see ever since we moved to Oregon.

Stanton at the Rim near the North Entrance
We got to the park about 1 hour to late to take the boat ride (next time Sam) so we did the obligatory drive around the lake. Sam's favorite stops was at Pinnacles, where the steam from fumaroles welded together the overlying pumice and ash into an erosion resistant hoodoo.

On the way back from Pinnacles, we stopped at the new trail in the park, a 2.5 mile out and back to Plaikni Falls. It was a nice little trail through the woods, and the falls at the end were a nice surprise (ok I knew there was a waterfall, but it was more impressive that I had anticipated). Sam, however was tired, so by the time we got to the falls she had transformed into a bit of a sullen teenager.

Plaikni Falls

I think overall, Sam was a little disappointed in the lake. (I found out later that, being who she is, what she really had wanted to do was go swimming in the Lake. She didn't expect only one access to the lake that was 2-3 miles down a steep trail to a non-existent beach that would have been hypothermia inducing cold at that rate!)