Rocky Mountain Trench Rivers

On my way home I had a nice view of the Rocky Mountain Trench.

Rocky Mountain Trench looking towards the north. 

The north arm of Kinbasket Lake is in the trench on the right.

The valley west of the trench is the upper Thompson River.

The Trench is a remakable feature that is about 1,000 miles long. The feaure jumps out in satelite imagery and Google Earth as the lower elevation of the trench forms a dark swath through the high snow covered mountains of the BC interior. The trench follows a major strike-slip tectonic fault, the Tintina Fault. There are other trench like feautes that are somewhat parallel, but none are as continuous. A number of major western rivers flow into and out of the trench. The river plumbing is complex and intriguing.

A few of the Trench rivers: Fraser, Canoe, Columbia and Kootenay. 

The source of the Columbia River is within the trench south of the photograph I took. Kinbasket Lake was formed in the Trench when Mica Dam was built across the location where the Columbia leaves the Trench. The north arm of Kinbasket Lake in the picure is the now flooded Canoe River. Not far north of the lake and Canoe River the Fraser River flows into the Trench and follows the Trench to the north for a long distance. Like the Columbia, the Fraser leaves the Trench and makes a U turn and heads south. I also marked the Kootenay River on the Google Erath view. The Kootenay flows into the trench from the east about 1 mile south of the Columbia source at Canal Flats, but the Kootenay heads south down the Trench whereas the Columbia flows north. Eventually the Kootenay exits the Trench and joins the Columbia.        

It is intriguing to think about how the ice ages may have rearranged the upper river systems. If we look at the current river routes one can imagine glacial ice filling the northern portion of the Trench and forcing the upper Fraser south into the Columbia. Or the Columbia being blocked by ice and flowing south down what is now the Kootenay route. I can also imagine that prior to the last glacial period the upper river routes may have differed possibly resulting in an even large Columbia or alternatively a larger Fraser.  

Returning Home with a 'View' of the BC Coast Range

 Returning home the southern portion of the BC Coast Range was obscured by low clouds; hence, I was unable to observe some of the challenging areas from past geology ventures of another work era as the plane descended towards Vancouver. One peak poked above the cloud cover.

The cloud cover was not a bad mimic of the past when the BC Coast Range was mantled with a massive ice sheet that flowed down into the lowlands into the northern Washington straits and out the Strait of Juan de Fuca and filling the Puget lowland with ice all the way to south of Olympia.

The Apple State and Tariff Talking Points

Washington State grows a lot of apples.

Washington State apple growers grows far more apples than we can possibly eat. Washington State exports a lot of apples. I watched the the Whitehouse discussion of tariffs. Apple exports to India was one of the talking points about tariffs: Misinfomed about apples and India (just past 7:40 miniutes) (thanks Don for the link). Mr.Jamieson, the United States Trade Representive stated that India charges 50% tariff on apples as a talking point about unfair trade. The talking point is not true (after-indias-tariffs-eased-washington-state-apple-exports-improved) (washingindia-ends-apple-tariffs) I would note that the talking point  right befoer apples about rice and Japan was aslo very misleading.

It will be interesting how Washington State Representaive Dan Newhouse responds to this issue. And in Washington State it is more than just appples. The State exports include wheat, lentils, chick peas and livestock feed, all a big part of Mr. Newhouse's district.    

Cold Weather Flowers

 

Galanthus Snowdrops

Our cold weather has ended in northwest Washington. It reached 50 F today with misty rain. Given that I had a water venture via kyak I was glad for the warm up although it was 43 F with light rain when I started out.

I noted the above snowdrops on a morning walk about when the temperature was 18 F. They get a head start on the grass next to chunk of the British Columbia Coast Range brough by the last glacial period. 

On the same walk I noted Salix scouleriana in bloom in a sunny spot at the edge of the forest. 

This willow is a native tree. Further back in the forest there is willow that fell a few years ago. The tree was 60 feet tall before falling. But the tree is still alive and the willow patch has thus begun to expand.

During the cold period the patch of Helleborus that had been in full bloom before the cold had hunkered down in its shady north aspect location. 

But post cold the flowers had opened up again.

1950 Jackson Creek, Skagit County Debris Flow

The Highway 9 corridor from Sedro-Wooley to Kendal follows the Samish River Valley and then after crossing a very subtle divide follows the South Fork Nooksack River Valley. I previously noted the alluvial fans associated with steams that flow into the Sanish River Valley (alluvial-fans-altering-samish-river).

Doing some review of the valley I came across this 1950 aerial of Jackson Creek with a recent debris flow scar path and deposit on the alluvial fan that extends out onto the Samish Valley floor.  

Jackman Creek 1950 with debris flow scar and debris flow deposit

Timber harvests have started up again in the Jackson Creek watershed, but the creek and the steep slopes near the creek have been partially buffered versus the previous log everything approach. The other substantive change is road construction across stream subject to debris flows have generally improved to reduce the risk of the road causing a debris flow. That said the creek is lined with steep unstable slopes and future slope failures and accumulation of debris  

Jackson Creek (2023, Skagit County) 

The Jackson Creek alluvial fan has resulted in a lake upstream from the fan and there is a lake down stream that is influenced by another alluvial fan at Mill Creek. Both of these lakes may also be influenced by beaver activity. Mill Creek had a debris flow in 1983 that resulted in a fatality.  

Lidar bare earth (via Skagit County)

It appears that a fairly large berm was built post the debris flow. There is a gap in the berm where a natural gas pipline was constructed. The dredge spoils are on the distill end of the fan and this spot may need periodic dredging to keep the creek passing under the railroad.

Highway 397 Road Cut West of Nine Mile Canyon, Part I

 

Highway 397 is a spur highway off of Interstate 84 south of Kennewick that accesses the Finley area to the east of Kennewick. The route by-passes Kennewick, angling across the northern slopes of the Horse Heaven Hills south of Kennewick. A road cut just west of South Nine Canyon Road (46.07'47", 119.04'38") got my attention with a variety of geology units. This post is Part I and is focused on the west end of the cut slope where a sedimentary unit is exposed between Columbia River Basalt Group lava flows.

West end of the cut slope

Lake sediments from between lava flows. The sediment appears tuffaceous.

A mix of basalt rubble and sediment

Basalt rubble within sediment with some very 'cooked' sediment

Sediment at base of lava flow

Closer view of sediment at base of lava flow

Reidel and Fecht (1994) geology map covers this area at a 1:100,000 scale. The scale precludes some detail and the sediment interbeds are not shown. Furthermore the road cut post dates the geology mapping of the area. They note that these interbeds of sediment are generally best exposed in road cuts. Where the interbeds are mapped they are referred to as continental sedimentary deposits. In places where gravel is present, the gravel appears to be sourced from ancestral Columbia River or Salmon/Clearwater River flow paths as the grvael contains rocks with a continental affinity.

The map does indicate that the lower basalt below the sediment is the Umatilla Member and the upper basalt is the Pamona Member. Both of these members are part of the Saddle Mountains Formation of the Columbia River Basalt Group. 

The delineation of these basalt flows was accomplished via a combination of geochemistry, magnetic polarity and isotopic ages.  

The lava flows in the chart above between the Umatilla and Pamona are generally more localized lava flows or smaller flows restricted to ancestral river valleys. The lack of flows between the Umatilla and Pamona as well as the thinness of Continental deposits at this site suggests this site was elevated relative to the broader Columbia Basin similar to today.

 

My Forest Enemy: Ilex aquifofium

While doing field work I come across what I have decided is a personal enemy on regular basis.

Eglish Holly (Ilex aquifolium)

I was able to pull this one out by the roots.

I at times visuzlize the Pacific Northwest forests in 10,000 years being a forest of holly. The holly shown above was in an old growth forest. I have come across holly in old forest areas ranging in elevation from the inland coastal areas to as much as 3500 feet in the Cascade Range. I have been digging it out of my own forest stand on regular basis, and when I can, I yank it out of the ground and stick it into a spot above the ground while traversing through the forest during a field ventures.  .

KUOW covered recent efforts to get this plant listed as a noxiuos weed (kuow.org/have-a-holly-noxious-christmas). The issue strikes me as a state government and ethics failure.