Tuesday, December 29, 2020

Geoducks

I have spent a fair bit of time on the high bluffs along the east side of Port Discovery. During some of those ventures a small boat has been off shore in a stationary position with the sound of engines running. At other times the boat is simply anchored near the end of an unpaved road adjacent to a cuspate shore form.  

Landslide complex with cuspate shore form in distance and anchored boat

Port Discovery with Olympic Range in the distance

The boat is used by divers for harvesting a lease tract subtidal geoducks. Dave Williams has an excellent write up of the history and management of the resource (pugetsound.org/geoduck-clams). The shellfish can be harvested during very low tides without diving.  (b-roll:-geoduck-beach-harvesting-aquaculture). However, a fair bit of the harvest is via dive boats at lease sites (youtube.com Geoduck Diving Harvest). The geoduck fishery is managed by Washington State Fish and Wildlife as well as the owner of the subtidal lands, Washington State (dnr.wa.gov/wild-geoduck-fishery)

The first time I tried geoduck was via a gift from shellfish business I did some geology work for. I have since dug for them a few times during very low tides. They are a fun prize to pull up out of the sand. One big goeduck is more than enough for a meal. But those big geoducks take many years to grow. As their value has increased management of the resource has become more important.    

Saturday, December 12, 2020

From the Columbia River to The Fraser River in 1824 - John Work

I roughed in the route of a 1824 Hudson Bay Company expedition from Fort George, the former Fort Astoria trading post, to what was later to become Fort Langley via Journal of John Work, November and December, 1824 via T.C. Elliot, 1912

Part of the scheme was to find the location of a trading center fort on the Fraser River that could receive export goods (furs) from the interior of western North American. Hudson Bay Company (HBC) was already concerned that the lower Columbia would end up in American possession. In part because Fort George was originally an American establishment. In addition, at that time navigation from the sea to the lower Fraser was far superior to the harrowing crossing of the entrance to the Columbia. However, while the Fraser River was a better sea access point, the Fraser River was not a good river transit route.  While a fort ultimately was built, Fort Langley, the Fraser proved to be an impossible navigation route from the interior.

The journal is a window to a different time, and for that matter a different place. I have been fascinated by the diversity of the people and interactions that took place in the brief period from 1790 to 1825. The assembled team for the venture clearly had a pretty good idea of the route they should take. The team included several Hawaiians (Islanders) as well as an Iroquois hunter and his slave.   

Note the time of year they traveled, November-December. While it does rain in November and December in western Washington, the outer coast and the southwest part of the state gets 'heavy rain', a term that Mr. Work used in his journal of his venture (correct spelling of his name was Wark). This was a hardy group. I contemplate how I would have performed portaging across wet ground and along shorelines, rowing for many miles, and camping in the rain, the heavy rain.   

Sunday, December 6, 2020

Rosario Fault on Crane Island north shore

During a work venture in the San Juan Islands I got a nice look at the bedrock along the north shore of Crane Island. Crane is a rocky island between the southwest end of Orcas Island and the northwest shore of Shaw Island. The ferry between Orcas and Friday Harbor passes along the south shore of Crane, but on this venture I was in a small boat and we ventured along the north shore. 

Crane Island is mapped as Constitution Formation on both the Bellingham 1:100,000 map (Lapen (2000) and the Roche Harbor 1:100,000 map (Logan, 2003). And both maps denote the Rosario Thrust Fault immediately to the north of Crane Island 

Portion of Bellingham Quad geology map (Lapen, 2000)
KJmc = Constitution Formation, JTRmcto = Orcas Chert, pPscg = Garrison Schist, pDit = Turtleback Complex, Qgd = glacial drift. Heavy black lines with saw teeth are thrust faults with teeth on upper plate.

Portion of Roche Harbor Quad geology map (Logan, 2003)

The Rosario Thrust is where the Constitution Formation has been faulted up over the Orcas Chert. The fault zone is a zone of highly sheared rock that in places include slivers and slices of other formations caught up in the fault zone such as the Garrison Formation denoted by Lapen (2000) on Shaw Island south of Crane Island. 

My observations of the fault zone exposed along the base of the steep north slope shoreline on the north side of Crane were consistent with other areas where the Rosario Trust Fault is well exposed along the shore near Rosario on Orcas Island (hence the faults name) and along the southwest shore of San Juan Island. The shoreline areas typically offer the best exposures of the fault zone.     

Highly sheared rock within the Rosario Thrust along the north shore of Crane Island

Brecciated and sheared bedrock at water line

Massive block of Constitution Formation above shear zone

On the uplands of Crane Island, the bedrock is generally massive metamorphosed sandstone of the Constitution Formation.  

Typical massive silica-rich metamorphosed sandstone

Orcas Chert is primarily composed of ribbon chert, alternating layers of silica rich 1 to 2 inches thick with thin layers of shale. The chert is derived from the accumulation of silica diatoms that accumulated on the ocean floor. The shale was derived from fine dust and silt that also reached the ocean floor. The layering developed after deposition when the ooze of silica rich and silty sediment was compacted. The age of the Orcas Chert is between 180 and 280 million years old. The Orcas Chert is part of terrain consisting of the related Deadman Bay Volcanics, which are ocean floor pillow basalts that are somewhat older than the Orcas Chert and likely formed the basement that the silica rich sediment that formed the chert unit was deposited on. The original depositional setting was an ocean floor area far from North America. The formation was moved to and accreted to the edge of North America via plate tectonics. During accretion the Orcas Chert was metamorphosed at high pressures.

The Constitution Formation was also originally an ocean floor assemblage; however, this unit is on the order of 130 million years old. The Constitution Formation consists predominantly of metamorphosed fine sandstone derived from a volcanic arc. There is some chert and basalt in the unit as well. This formation was also accreted to the edge of North America. A lack of older aged sediment, North America sediment, suggests the sediment may have been derived from an ocean island arc. 

The Rosario Thrust Fault and the juxtaposition of the Orcas Chert and Constitution Formation took place after accretion -- note that the younger Constitution is thrust over the older Orcas Chert.    

The map pattern shows that Crane Island is klippen of Constitution Formation on the underlying Orcas Chert. Parts of the Constitution Formation have been stripped away leaving the Constitution Formation as an 'island' on the Orcas Chert and as well as the rock formation that makes up most of Crane Island. 





 

Sunday, November 29, 2020

Political Sunday: Remembering Malden and Pine City Okanogan Valley


Malden Post Office before the fire

NPR did a brief story on Malden, Washington and the lack of a National Major Disaster Declaration after the wildfires in Washington State in early September (HERE). The wildfires in early September burned nearly all of the town including the town hall, post office, food bank, library and fire station. Pine City, a few miles away also was badly burned and one fire burned across 60 miles of Okanogan County and into Douglas County including burning into the City of Bridgeport. 

The NPR story provided no explanation as to why a National Major Disaster Declaration has not been issued. One theory is politics because Washington State votes Democrat of late and the President does not care for the governor; however, Malden is located within a US Congressional District represented by Cathy McMorris-Rodgers, a Republican. The Okanogan area is represented by another Republican, Dan Newhouse. Malden voted 2 to 1 for Donald Trump for President over Joe Biden. So if the reason is politics, it is doubly unfair. Ms. McMorris-Rodgers stated shortly after the fire "I will be working with and supporting state and local officials and doing everything I can on the federal level to ensure our communities have the resources they need to rebuild." She, did sign along with the entire Washington US congressional delegation a letter to Mr. Trump in support of Declaring a Major Disaster (murray.senate.gov/letter).

So far Malden does not have the resources to rebuild. The town had an early burst of development when the railroad came to this location with a rail stop in 1906. After the railroad pulled out their facilities in the 1920s, the town declined. There is no commercial activity remaining, but with over 80 homes destroyed, Malden will have a hard time bringing their community back without help.



   

     

Saturday, November 28, 2020

East Sound Fjord

I previously put up a post on the fjord-like feature of East Sound HERE. This fall I had a chance to get some better on the ground perspectives on this fjord.

View across fjord looking east from the slope of Mount Woolard across the fjord to Mount Constitution

View of southern end of fjord with Cypress Island in the distance

View down the fjord from Lookout Hill 600 feet above the fjord

View across the upper north end of the fjord from Lookout Hill to Mount Constitution

The bedrock on Lookout Hill may have at least in part originated from northern Europe or Greenland. The bedrock consists of Turtleback Complex. Age dates from igneous rocks in Turtleback Complex have a huge age range with dates ranging from 350 million years to 500 million. The older ages do not have western North American correlatives. The Turtleback Complex is one of several terrains old accretion terrains along western North America. Some of these terrains may have a connection with the Baltic region and/or the northeast part of Laurentia. Schermer and others (2018)  provide an overview as part of their study on the Yellow Aster Complex in the North Cascades.  



Saturday, October 31, 2020

Typhoon - Welcome to the Endgame

Kyle gives us a bit of what he has been working on during this strange year (https://wearetyphoon.com/): "This song belongs in the present moment and it felt important to get it out in the world now." I have found music and art to be of great help during this past year, but the interface has been altered by COVID. If you can, support the musicians and artists that help shape your perceptions. 

A bit of lower Columbia River landscapes in the video with the song. The tunnel and tenor of the song does fit well with this next Tuesday. We will see what is on the other side.

Friday, October 23, 2020

The Sounds of October

This is my second October living full time at our current home. October is a month of change. Yes, the colors change. Maybe golden leaves on the the big leaf maples. The initial fall rains flipped the brown grass to green. 

But the big change that has gotten my attention are the sounds: 1) The early rains brings out frogs. The tree frogs begin some chorus activity before the colder air shuts things down again - no calls tonight as the temperature is down in the 30s and perhaps 20s by morning.  2) One of the abrupt sound changes is the early just as it gets light sound of guns. Our home is near tracts of State Fish and Wildlife lands as well as a hunting club property and farmland that allows hunting. October brings hunters to sit in blinds awaiting ducks and geese as well as a few pheasant hunters that venture to the brushy thickets between fields. I picture them sipping coffee or whiskey waiting for the ducks or geese to fly near. 3) Another abrupt change is the roar of wind through the forests west and south of us. This evening the wind is coming out of the north - calm around the house but very audible from the upper tree canopy. When the wind really cranks up from the south, a flute like sound emanates from the east side of the house. 4) My favorite is the great horned owls calling in the forest at night. 5) The massive flocks of snow geese honking overhead a week ago in the early morning made me think "welcome back from Siberia".