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.  

Windfall and Dog Hair

I plotted out a route to a steep slope at the headwaters of a creek in the Northwest Cascades. While approaching the site I noted windfall trees on the edge of a clearcut.

While walking the road and a section of trail took about 2 hours to cover 6 miles with a fair bit of elevation gain and hiking out took about 1.5 hours as it was downhill, the last quarter mile to the steep slopes I wanted to reach took nearly an hour each way. 

Windfall trees and dog hair young trees

Dog hair western hemlock obscuring downed trees

It is a slow process navigating over fallen logs and brancheds that tend to break. It did not help that portions of the area were also steep. 

I did reach my goal of getting to the steep headwater slope - that presented its own challenge as there were cliffs in the forest.

Very steep forested slope

Made for a bit of a long day and light got a bit dim before getting back to my starting point, but I did get some nice views as the clouds broke up. 

Whitechuck and Glacier Peak

Whitehorse and Three Fingers

Volcanic Ash at Palmer Lake

 A road cut along the southeast side of Palmer Lake consists primarily of angular rocks, but a thick white layer is located below the uppermost layer of angular rocks. The white layer is volcanic ash. 

Layer of volcanic ash withg talus and scree below and above the ash layer

The ash is very fine powder

I am not sure of the source. There are reported ash depsits to the south near Chelan and the soils of the Waterville Plateau that have been connected to Glacier Peak. I have observed that ash and it is generally coarser. I suspect this is Mazama ash from the massive Mount Mazama (Crater Lake) eruption There is widespread ash depsoits from Mazama throughout eastern and central Washington. Because layers of volcanic ash are common in the Pacific Northwest, they serve as extremely good stratigraphic markers when applied to geologic and archaeologic problems, as long as they are correctly identified and correlated. The ash is a time marker for the deposition of the talus and scree exposed on the cut slope.   

View of Palmer Lake from the north end of the lake.

The ash exposure is at the base of the cliffy areas in the central distance.

Chandler Narrows I

On my way to another venture I observed this road cut west of Benton City in the lower, eastern Yakima valley.

The location is mapped as an ice age flood deposit by Reidel and Fecht (1994). My interpretation of the road cut exposure is that both the lower silt and the upper gravel were deposited during a ice age flood events.

The silt would have been deposited when the site was temporarily inundated by the short lived Lake Lewis.

Map of Lake Lewis with water level at 305 meters.

White arrows show flow path of ice age flood waters into the lake from left to right: Columbia River, Drumheller Channel, Washtucna Coulee, and spill over into the Snake River.

Lake Lewis formed due to the restriction at the narrow gap at Wallula Gap through the Horse Heaven Hills. The backing up of water resulted in deposition of silt in the queit water areas of the temporary lake including extensive silt deposits around the area of Benton City and up in the Yakima Valley.

As the lake drained down, water that had filled the Yakima Valley had to pass through a relatively narrow exit at Chandler Narrows.

The relatively narrow lower Yakima Valley resulted in high flow velocity of the water as it drained out of the valley. The result was an area of classic eastern Washington scab land in the eroded basalt up stream of the gravel deposit.

Basalt cliffs with latge basalt blocks ripped off the cliffs along the 

Chandler narrows reach of the Yakima Valley

Patch of grapes in the scab land landscape

This are is a hot wine area just west of Red Mountain

Thick gravel deposits just belwo the Chandler Narrows

A Stop at Agate Fossil Beds National Monument

When I lived in Colorado I ventured north from Colorado during a 5-day weekend with a scheme of visiting some of the places my father and grandmother told me about from a past family venture they had with my grandfather. One side adventure I wanted to make was a stop at Agate Fossil Beds National Monument (https://www.nps.gov/agfo/index.htm) in the Nebraska panhandle. 

My scheme of visiting the Monument got sidetracked. At a county road intersection well south of the Monument I saw someone pop up out of the grass by the side of the road waving a bit frantically. I stopped. The person I saw had fallen aslseep waiting for the rare car that passed by. He needed a ride to a town past the Monument. Given the lack of vehicles, I opted to pass by my planned turn off and took him into town. We went into the cafe where he bought me a burger and beer on the family tab and called home for a final lift. It was a well worthwhile 'good deed' that was a nice part of the trip. However, I did miss the trip to Agate.  

A fair bit of time has passed since that venture, but I always hoped to get another chance to see the Agate Fossil Beds Monument. Recently I had another chance. 

Heading west across the high plains of western Nebraska 

I did have some good luck in that the blizzard that had blown through the area a couple days before had not blocked my route. And the cattle were courteous and politely curious. 

The Monument landscape is high plains dissected by a river valley and associated small tributary streams that expose the Miocene age soft sediments protected by a cap of silcrete and limestone lake deposits. 

Silcrete and limestone cap above the Miocene sediments.

The fossils were found in fairly soft Miocene sediments. The fame of the site was the discovery of a bone yard of fossil bones in the late 1800s. That pile of bones has been interpreted to have been a watering hole with the idea of many animals dying at the watering hole during a bad drought. Subsequent fossil bone finds in the Monument have added to our understanding of life on the plains 22 million years ago. 

I took a hike through a small area of the Monument. No big bones exposed, but there are plenty of fossils. 

Miocene soil horizon just below the cap rock

Worm burrow casts and root casts in the soil 

Careful study of these soil horizons and small fossils tell a great deal about the setting. There is one burrow cast preserved on the trail that took a few years to figure out. 

Paleocastor burrow protected from erosion by a plexiglass box

Paleocastor was a dry land beaver

A collection of some of assembled skeletons from the fossils are on display at the visitor center. I am not a paleontologist. When I taught the paleo lab class I was a half a day ahead of the students at best. I have a deep appreciation of the field and the workers extracting information out of the fossils and the soils and rock the fossils are found in and passing that deep history to casual visitors to museums and in this case a National Monument.

There is another aspect of Agate Fossil Beds that was a delight and links back to my father and grandmothers stories from their travels. They visited the Red Cloud Agency on the Pine Ridge Reservation. That visit left a lasting impression that was passed down to me through their stories. Red Cloud was a friend of James Cook, the rancher that ranched in what is now the Monument.The friendship and exchanges between Cook and Red Cloud resulted in a family collection that the Cooks later gave to the park and are on display at the visitor center. 

Red Cloud's people had left a lasting impression on my family. Seeing the display and picture of Red Cloud and the display of Lakota culture solidified that family impression and the connection to Pine Ridge and the complex and at times tragic history of the area.     

Photograph of Red Cloud's bedroom