The Bottom and Shores of Lake Missoula

On the way to Missoula we passed through a daylight road cut on Interstate 90 near the hamlet of Alberton approximately 16 miles north of Missoula. I'd passed through this road cut before, but this time I was ready and pulled out my camera for a couple of pictures as we passed through the exposed silts on either side of the road. Roadside geology on the fly.

Layered silts and clays at the Nine Mile Section on Interstate 90 northwest of Missoula, Montana

These distinctly layered silts and clays represent alternating paler river silt deposits and the darker lake deposits. Chambers and Alt report 36 distinct layers. The lake sediments were laid down on the bottom of Lake Missoula each time the lake filled with water when the Clark Fork River was dammed by glacial ice between 18,000 and 15,000 years ago. As can be seen in the distinct silt layers, the river was dammed and then drained on numerous occasions - something like 40 times.

Looking at the slopes of the mountainsides east of Missoula on either side of Hellsgate where the Clark Fork River flows out into the broad valley where Missoula is located horizontal lines can be seen on the slopes. These lines mark the former shoreline of glacial Lake Missoula. They are wave cut terraces marking the various lake levels as the lake filled with water when the Clark Fork was dammed. The entire Clark Fork valley filled with water along with tributary river valleys such as the Bitterroot Valley south of Missoula. In all the lake covered as much as 2,900 square miles.

Faint horizontal lake shore terraces on the slopes above Missoula. Montana

The lake filled until it floated the ice dam blocking the river and then the entire lake drained rapidly across eastern Washington, down the Columbia Gorge through present day Portland shaping vast tracts of the landscape of Washington and Oregon. Water backing up the Yakima, Walla Walla and Willamette valleys silts that created some of the best farmland in the world.

The rich farmland of the Willamette Valley was the impetus of the early settlement of the Pacific Northwest by Americans. This in turn led to the bustling City of Portland. And from Portland two bands traveled up the former flood route to the former lake bed in Missoula last week. We very much enjoyed the Decemberists and Typhoon during our stay in Missoula.  Typhoon was the opening band. I loved the audacity of a 12 or was it 13 member band.

Coal Stories - Including a Link Showing Local Coal Politics at Work

Lots of coal news this past couple of weeks with a fair bit revolving around the Powder River Basin of Wyoming and Montana. What does the Powder River Basin have to do with the Washington landscape? Coal from the Powder River is currently being shipped via long coal trains through Washington State to a coal terminal in southwest British Columbia and there are active efforts to construct very large coal shipping terminals in Washington State to ship Powder River coal.

New York Mayor Michael Bloomberg announced a $50 million dollar gift to the Sierra Club to help eliminate coal fired power plants washingtonpost./national/health-science/mayor-bloomberg-gives-50-million-to-fight-coal-fired-power-plants. Not much direct impact to Washington State since Washington's only coal fired electric power plant is proposed to close in the next few years. But there are indirect impacts as coal use shifts and possibly an impact on CO2 and the rate of climate change.

In the north Powder River Basin a billionaire candy magnate Forrest Mars purchased a one third interest in the Tongue River Railroad. By purchasing the stake in the railroad, Mars will block the railroad from crossing his ranch but now owns a stake in the rest of the line along with Arch Coal and BNSF. Arch and BNSF along with Mars plan to build a railroad line to Miles City, Montana so that Powder River coal mined in the Ashland area can be shipped via rail to the existing main line railroads through Miles City. From Miles City Arch and BNSF can run coal trains to power plants and have every intent to use railroad lines to coal terminals for shipment to Asia. Mars apparently will no longer be supporting legal efforts to block the railroad. coal railroad fight deal.

I found this letter to the editor in the Billings paper an interesting juxtaposition of property rights and coal mining development and railroads billingsgazette/mailbag. The construction of railroad lines through the Powder River Basin has opened up coal mining of the basin far beyond its previous mining activity. The State of Montana has eminent domain laws that are very favorable to railroad and pipeline proposals. The intent of the laws is to ease the opening of otherwise non economic coal deposits. The ranch land taken by private corporations through eminent domain is not expensive as much of it is dry land ranch, but the impact to ranchers is extensive. What I find interesting about the Montana laws is that normally Republicans are associated with private property rights, but when it comes to eminent domain laws in Montana the Democrats stand behind the private property rights of ranchers and the Republicans are strong advocates for eminent domain for use by private corporations - in this case railroads and gas extraction companies.

When I got back to Bellingham I read an article by Bellingham Herald's John Stark on Bellingham's version of coal politics bellingham-mayoral-candidates. The incumbent mayor is attempting to turn the entire race into a campaign over the proposed coal terminal despite the mayor having no role in the permitting process. Mr. Stark pointed out that the mayor initially was supportive of the project in February. Mr. Stark did not note that in October of 2010 the mayor proposed a resolution in favor of the coal terminal 25oct2010_Resolution Supporting Coal Terminal. The final recital of the resolution states "Whereas the Mayor of Bellingham, Dan Pike, joins the Council in its strong support of this project". The resolution was withdrawn as apparently the City Council did not share the mayor's enthusiasm for the coal terminal.

And lastly this press release showing that powerful financial forces are at work in the Powder River Basin of Wyoming and Montana.

ST. LOUIS, July 13, 2011 /PRNewswire via COMTEX/ --

Peabody Energy (NYSE: BTU) today announced that it is the winning bidder for the control of approximately 220 million tons of low sulfur coal reserves in the Powder River Basin of Wyoming.

The winning bid for the reserves was $0.95 per mineable ton, made through a sealed bid auction process. The company intends to add the "Belle Ayr North" reserve area to the assigned reserves related to the Caballo Mine, which had 2010 sales of 23.5 million tons and reserves of 822 million tons. The new reserve block would extend the mine life, increase the average Btu of the mine, allow for increased mine production as demand warrants and enable greater mine optimization.
The new reserve lease also extends Peabody's leadership in the United States' largest and most productive coal region. Peabody controls 2.9 billion tons of Powder River Basin coal reserves, and is well-positioned to meet the strong expected long-term demand growth from the region. The Powder River Basin continues to grow to serve new power plants and increased consumption from existing plants. Powder River Basin coal also is in increasing demand for exports to fast-growing Asian markets.
Peabody is the world's largest private-sector coal company and a global leader in clean coal solutions. With 2010 sales of 246 million tons and nearly $7 billion in revenues, Peabody fuels 10 percent of U.S. power and 2 percent of worldwide electricity.

Refrigerated Air on the Skagit River

I got a nice dose of 90 degree weather the past few days. Not much shade, but then non of that view obscuring vegetation. Had a nice break in an ice cold lake and cold beer afterwards.

After being in 90 degree weather it was back to cool wet western Washington and temperatures in the 50s(to be fair it was apparently sunny and warm while I was gone). The cold water of the Skagit River was cold enough to cause the wet air above the river to condense creating a cold, foggy layer of air along the top of the river.

Touchet River - Another Entrenched Meander

Entrenched meanders on the Touchet River on the left portion of photo

The river is flowing south away towards the upper portion of the photo and

the Walla Walla River. The Columbia River and curves through Wallula Gap in the upper right.

Note the longitudinal dunes aligned towards Wallula Gap to the right of the Touchet River

The Yakima River (antecedent-yakima-river) is not the only entrenched meander river in eastern Washington. A quiet, off the beaten path section of the Touchet River flows through a set of entrenched meanders on its way to the Walla Walla Valley. Although I have driven the road along the this section of the Touchet River, I had never thought of it as an entrenched meander until passing high overhead on a recent trip.

The Touchet River was inundated with flood waters from the great outburst floods from Glacial Lake Missoula as the flood water backed up at the narrow passage of Wallula Gap forming a temporary lake (Lake Lewis) that filled the valleys of the lower Columbia Basin in eastern Washington.

Map showing highest flood levels from the Missoula Floods 

Silts carried by those floods were deposited throughout Lake Lewis particularly in quiet back water areas. Each flood left a distinct layer of sediment and at least 40 distinct layers have been identified. These layers are well exposed in the lower Touchet Valley and the sides of the Walla Walla Valley in the vicinity of Touchet, Washington and are called the Touchet Beds.

Despite the flood sediments the entrenched meanders remained in tact. This particular area is not an area of uplift so the entrenched meanders may be a result of lowering of the Columbia River system starting approximately 3.4 million years ago.

On their return journey, Lewis and Clark followed the Touchet River on horseback as the valley was a trail from the Wallula Gap area to the Snake River near Clarkston. The party passed along the entrenched meanders of the Touchet on the west side across an area called Eureka Flats. Clark noted the sand dunes on Eureka Flats in his journal.

Antecedent Yakima River

The Yakima River meanders through the Yakima Fold Belt

between Ellensburg and Yakima

River flow is from lower right towards upper left

The Yakima river drains a large area of the east side of the Cascade Range with headwaters extending up to the crest of the range. The river supplies water for irrigated farms throughout its length and water rights and lack of water rights has been an ongoing struggle along the river for many years.

I had a nice view of the Yakima River between Ellensburg and Selah on a recent trip. The Yakima River's passage through the ridges of the Yakima Fold belt is a classic antecedent river. That is the river was there before the ridges formed. The meandering nature of the ancestral river is preserved where the river is entrenched and deeply incised through the ridge areas. The Yakima Canyon in the above picture is a classic example of entrenched meanders of an antecedent river.

An interesting feature of the river is that outside the meander loops stretches in the entrenched valley the river is more typically a braided stream with multiple rapidly shifting channels. The river alternates between these styles of flow as it passes through broad alluvial valleys and ridges.

Broad nearly circular loop forming a goose neck just south of the Kittitas Valley near Ellensburg

The exact cause of why the Yakima River, and for that matter a number of other rivers in the Columbia River system) became so entrenched has not entirely certain. The entrenching of the Yakima began approximately 3.4 million years ago with large volumes of previously deposited sediments in the valleys between the ridges and within the Columbia Basin removed (Reidel and others, 1994). I like the idea that the gradient of the river system changed once the Columbia became established in its current route through the Cascade Range. Prior to the down cutting there was a period of wide spread lake deposition within the Columbia Basin suggesting that Cascade volcanism had created a blockage of the Columbia system.  

Cascade Rain Shadow, Edge Habitat and Wolves

Cascade rain shadow

After flying up through the cloudy sky of western Washington last week I got an overhead view of the rain shadow while crossing the Cascade Range. The sky or in my case the view changed abruptly from complete overcast to clear. With the change in cloud cover and rain fall amounts there is a rapid change in the landscape from tree covered thick forest to grass and scrub steppe. 

Vegetation shift from forest on the west (right) and grass lands to the east

I was particularly interested in this landscape as just a few days before a wolf pack had been confirmed near this area. The mix of forest and grass lands on the east slope of this part of the Cascade Range makes for very good elk and deer habitat. Wolves have been reported in this area for some time by a locals but were very recently confirmed to be present via motion cameras and DNA testing.

On the ground I have always thought of the ecosystem in this area as being very dynamic. It is an area with cold snowy winters that sometimes can be very severe. The summer can be exceptionally hot and is very susceptible to big grass land fires and forest fires. The elk and other wildlife move east and west and up and down in elevations with the seasons moving to where the forage is best. With wolves entering the area, the elk will likely make moves to avoid predation as well. And of course how this plays out with people will be a new episode in natural resource management for Washington State.  

Conglomerate Erratic and Link to Northwest Geology Field Trips Write Up of a Huge Erratic

Last week while working along a shoreline I came across a conglomerate boulder on the shoreline of Dabob by off of Hood Canal. The boulder was transported by glacial ice from an outcrop that is at least approximately 80 miles away. The boulder is a glacial erratic. I have seen numerous conglomerate erratics, but more often than not they are metamorphosed conglomerate. that is they were cooked a bit and slightly recrystallized. Meta conglomerates will break across the cobbles and pebbles whereas non metamorphosed conglomerates break around the pebbles and cobbles.   

Conglomerate Erratic

Close up of the pebbles showing surface of boulder broke around pebbles

David Tucker has become the gate keeper of Washington State erratics. He just put up a post on a huge erratic at the edge of a neighborhood park in Lake Stevens the-lake-stevens-monster-largest-erratic-in-washington-largest-in-the-us?. His posts on erratics are well worth checking out. For a magma and strato volcano guy he has been behavior has become erratic. (Yuk, but I could not help it)

As simple of a geologic concept as erratics are they are still a great deal of fun to discover. And it is great fun to speculate where they came from particularly when they are many miles from the nearest bedrock outcrop or are very out of place compared to the nearby bedrock exposures such as the erratic pictured above. This particular erratic appears to be a block of Huntingdon Formation or Chuckanut Formation from Whatcom County. Typically most people only wonder about the big erratics. However, David points out that even the pebbles in glacial drift are erratics.