Friday, September 28, 2012

Greetings from Cilento

Posting has been limited due to an intense run of field work, a flurry of work before vacation and now vacation. One of the great things about travel is it can provide insight on your on landscape or at least cause questions to be asked.

Since I am in Nazionale Parc de Cilento, I found Timothy Egan's experience in Italy and his concern about public lands in the-geography-of-nope very timely relative to my own experience. He starts out with a comparison to Italy.

In the mean time I am enjoying warm weather and very good food. 

Saturday, September 22, 2012

Mount Baker: MBVRC

I recently had a project up at the lower end of Baker River valley and had a brief view of Mount Baker. Seeing Mount Baker from the east or southeast triggers associations with people. Some of my earliest field work was on the east side of Baker looking at metamorphic rocks with Chuck Ziegler. Chuck and I came across lots of Mount Baker stuff as the volcano has piled up on top of the metamorphic rocks we were seeking. A lot of work has been done on Baker since that time. The latest was a very cool project written up nicely by Dave Tucker:


Wednesday, September 19, 2012

Lost and Found in the Field: Minor Cause of Celebration

Somewhere on the east side of Mount Baker below a forested but rocky ridge there is a 3-pound sledge hammer that I inadvertently left at an outcrop. By the now the wood handle is likely gone. It is the one hammer I lost in the field. I figured out that is where I left it the next morning, but the level of effort required to return to the site was not worth the hammer. I replaced that hammer with "The Enforcer" a 5-pound sledge that nearly all rocks would yield to when collecting samples.

A week ago I came back from a field adventure and realized my Brunton Compass was missing. How? It was on my belt. Running the day back, I realized I had slid my camera off my belt and tossed it to an associate to take a picture of a feature he was much better positioned to photograph. While Pulling the camera case off my belt the Brunton followed it. In this case a retrieval was worth the effort. Five minutes of looking around the surmised location and, Yes...

Found it!

Monday, September 17, 2012

A Lucky Break with a Small Glacier: Observing the Eldorado Contact

I was doing some research on snow pack and glacial ice in the Cascade Range and looked at few of the glaciers that were in my graduate field area. My graduate field work was focused on rocks not glaciers, but glacial ice and snow turned out to play a critical role to my work. And after looking at some glacier and snow pack images of my field area, I realize that I may have been very lucky.

My graduate field area in the North Cascades - The Eldorado Contact indicated by #2

This is the second post regarding my past graduate work (#1 on the map above is HERE).

The initial goal of my graduate work was to determine the direction and timing of the faulting that placed the low pressure Eldorado Pluton adjacent to very high pressure metamorphic rocks in the Crystalline Core of the North Cascades Range. The contact between the Eldorado Pluton and the adjoining high grade schist was well mapped, but the faulted nature had been surmised by the sheared rocks observed near the contact and the disparity between the high pressure mineral assemblage in the schist and the moderate pressure mineral assemblage in the pluton. The actual mapped fault had not been previously observed even though it showed up on the Washington State Geology map at the time.

So the big challenge was actually finding the contact. My initial efforts focused in the Cascade Pass area and a few other areas that looked promising, but I was frustrated by the vegetation, soils, glaciers and very inconvenient younger intrusive rocks (I cursed andestic dikes and pegmatites) covering or obscuring the needed exposures of what I wanted to see. I found wonderful exposures of high grade metamorphic rocks and wonderful exposures of Eldorado Pluton, I measured foliations and shear markers, collected oriented samples for later microscopic viewing, but the actual fault contact remained hidden.  

Site #2 on the map above is where I finally reached a contact location. This site took some effort to reach. We hiked into a high camp from the Cascade River Road up the brutal slog to Monogram Lake and then a couple more tired miles up to a bedrock ledge next to a glacier that was out of the bear invested meadows. The hike to this camp involved nearly 5,000 feet of elevation gain followed by a drop of 1,000 feet and then another climb of 1,000 or more. The first night at this camp the mountains became socked in with fog and it was too dangerous to attempt route finding towards the contact I so much wanted to see. We did other work before the weather turned really bad and we retreated out of the sleet and rain. Hence, the hike had to be repeated.

This second effort brought success. And in retrospect a bit of great luck provided by the small glacier on the north side of the ridge. 

Google Earth image from Summer 2011.

Previous geologists had passed along this ridge. I suspect that their routes took them along the high meadows on the south side of the ridge. And if that is the route they followed, they would not have been able to see the contact between the Eldorado and the schist. I hiked all over that slope and could not find a contact. They would have been close but would nit have seen it.

But on the north side of the ridge I got very lucky. Previous mappers had worked this area in the 1960s. Look at the above image and one can see a nice fresh slab of exposed bedrock north and down slope from the small glacier. The glacier has receded exposing a slab of fresh bedrock. I am not certain that the area of exposed bedrock in the 2011 image was glacier covered on the 1960s, but I highly suspect it was and at the time I was pretty convinced I was looking at fresh outcrops no one else had ever seen. But looking at the 2011 image above, I realize that I was even luckier than I thought. I had zoomed into the image to see if I could see the Eldorado/Schist contact, but in the above image the contact is ice covered.

2011 was a big snow year in the North Cascades and the snow lingered late. In addition, the small glacier appears have advanced or expanded. Indeed other Google Earth images hint at an expansion of the small glacier. The point is, if one were to traverse the slope below the snow and ice at the time the 2011 image one would not be able to observe the contact between the Eldorado and the adjoining schist like I had.

The Google Earth image from 1998 though shows much less snow and ice and the contact between the units can readily be discerned.

Google Earth 1998
Dark amphibolite schist is on the left of contact line and light Eldorado tonalite is to the right

In all my tromping around the Eldorado Pluton, this was the only place where the contact was not obscured. This one site more than made up for the lack of good observations elsewhere with over 300 feet of continuous contact between formations extremely well exposed in freshly glaciated bedrock slabs with virtually no weathered surfaces.

And from a research perspective, I was lucky again. The fault turned out not to be a fault. This one site definitively demonstrated that the Eldorado Pluton had intruded into the surrounding bedrock. This finding completely altered my thesis project and provided a nice data point in timing of major North Cascades tectonics - the high grade metamorphism took place after the pluton had intruded into the schist (Intra-arc loading). A small contribution to the bigger picture. And I take some self-satisfaction that a fault that was previously on the State Geology map has since been removed.

I should add that after spending a lot of time trying to find the Eldorado contact, I had become suspicious that it was not a fault. This was particularly true after going from outcrop to outcrop in the meadow area on the south side of the ridge shown above. The tricky climb down to the north side of the ridge had to wait the next day, but before we made the descent, I was fairly convinced I was going to see an intrusive contact.   

Sunday, September 16, 2012

Down the Ballot

Best wishes to Brandi Carlile and Catherine Shepherd - You deserve the best. Brandi grew up in Washington and began her career here including visits to Bellingham. Perhaps Washington State citizens will see that folks like Brandi and Catherine can pursue their dreams together by voting for Referendum 74.

Friday, September 14, 2012

Soft Sediment Deformation

"Strata either perpendicular to the horizon or inclined to the horizon were at one time parallel to the horizon." - Steno, 1669.

Steno's basic principle of original horizontality is a key principle in figuring out geologic structures. But sometimes sediment layers loose their original horizontal aspect through soft sediment deformation. Rapid deposition with water being squeezed out of underlying sediments can stir otherwise nice horizontal layers into a bit of a mess.

These particular soft sediment deformed units are within glacial advance outwash on the west side of Marrowstone Island in Jefferson County. The sand and silt and gravel layers were deposited by melt water streams from the advancing glacial ice at the early stages of the last glacial period in the Puget lowlands approximately 18,000 years ago. The sediment may have been deformed by simply very rapid deposition or by the loading of the unit by a couple thousand feet of ice.

Earlier this year I was doing some work on the shore of Bainbridge Island and got a view of some soft sediment deformation from above on a wave cut platform beach.

Haugerud (2005) described this unit at another location on Bainbridge as appearing to have been stirred with a spoon. An apt description that I have used since.

Thursday, September 13, 2012

The Best Washington Geologic Rest Area

I do have a favorite Washington rest area. The south bound Intertstate 82 rest area just north of Selah is my favorite.

I-82 south bound rest area near Selah

First there is a great view of the concrete arch bridge across Selah Creek 325 feet below. A plaque indicates that at the time of construction it was the longest concrete arch span in the United States.  

Fred Redmon Memorial Bridge

Across the interstate from the rest area is Pushtay an odd hill that with a volcanic cone shape, but is an erosional feature pushtay-odd-hill-near-selah-washington.


A short walk to the north on a paved path provides great views down into Selah Creek canyon and the Selah Cliffs Natural Area Preserve managed by the Washington State Department of Natural Resources. This area has been set aside for protection due to several rare plants that grow on the steep slopes at the base of the cliffs.

Not yet well understood changes in the area the Columbia River cuts through the Cascade Range likely caused an increase in gradient on the Yakima and thus increased the rate of down cutting by the Yakima further enhancing the entrenched nature of the current river as well as the tributary Selah Creek. Possible changes on the Columbia River route through the Cascade Range may have been the result of volcanic activity.
Selah Creek Canyon and cliffs

Talus and strings of talus on the slopes north of Selah Creek

Another feature that can be seen are strings of talus on the slopes across the canyon from the rest area. These features are fairly common in eastern Washington. The features are thought to be formed primarily by summer cloud-burst rain events (Kaatz, 2001). These types of events are not common, but Kaatz suggested that they area a primary geomorphic process in eastern Washington that had been perhaps under appreciated.   

Wednesday, September 12, 2012

Lake Whatcom Reconveyance: Vetting a Possible Amendment

No vote yet on the Lake Whatcom Reconveyance. Sam Crawford has proposed an amendment of the area reconveyed based on slope stability maps produced by the Department of Natural Resources. He requested the delay so that the proposal could be fully evaluated. Good deliberative governance.

More later on the proposal and other thoughts as time permits.

Tuesday, September 11, 2012

Lake Whatcom Reconveyance: When the Going Gets Weird

Via Sam Crawford on Facebook.

The issue is the Mount Baker School District Board was concerned about forest revenue from State Forest Board Lands in the Lake Whatcom watershed. As they should be. Whatcom County is considering a reconveyance from State control to County control of Forest Board lands in the Lake Whatcom watershed lake-whatcom-reconveyance. A donor through the Whatcom Land Trust made a donation to the school district that far exceeded the revenue that the Lake Whatcom Forest Board lands would have provided.

The school board's charge is to do what is best for the students. The Mount Baker School Board has actively opposed forest board land restrictions and have been very open advocates for logging to generate money for schools. They have actively lobbied for a different means of logging revenue distribution. Rural school districts in forest rich areas are very often allies with timber industry interests, and Mount Baker School District has consistently been a logging advocate. But the motive is not logging per se; the motive is revenue for education. To attack a school board for making the fudiciary responsible choice points to other motives and a willful disregard of facts. 

The Lake Whatcom reconveyance will be up for a hearing this evening (Tuesday, September 11) before the County Council. The Council members have been blitzed with a campaign in support and in opposition. The opposition has tried many angles and one is illustrated above. Hunter S. Thompson provides a line that might best describe the theatrics of the reconveyance opposition, "When the going gets weird, the weird turn pro". 

Monday, September 10, 2012

Road Abandonment

Large water bars cut into abandoned road
Under Washington State Forest Practice rules, inactive logging roads are required to be closed and properly abandoned. Abandonment is to avoid road caused landslides years after the road is no longer in use. Old legacy logging roads have been a huge source of sediment to streams and have greatly increased the frequency and magnitude of landslides and debris flows. Timber land owners have been working for well over a decade to properly abandon thousands of miles of old roads. The deadline for completing the work has been extended as progress has been challenging for the industry.
The goal is to make sure drainage is managed so that water doesn't end up where it could cause a problem. Hence, large water bars are put in place to prevent water from becoming concentrated and culverts that might become plugged over time are removed.
This particular road is not an old road. It was constructed 5 or 6 years ago, but is now no longer needed as the timber harvests that it was used to access have been completed and it is in the process of being put to bed until the next harvest cycle. During its operation three debris flows were triggered by drainage problems from the road and severe erosion was caused by intercepted surface water and captured perched ground water.  
Removed stream culvert

Removed stream culvert and filled ditch to prevent water from flowing along road side to a hazardous location.

View of a spur road that had been abandoned two years ago and was now grass covered

One of September's field hazards

Sunday, September 9, 2012

Quimper and Pysht Fossils

I encountered a few fossils this week while in the field. The first were some marine fossils in the Pysht Formation on the north side of the Olympic Peninsula. Nothing dramatic perhaps, but careful study of small fossils allows for correlation or non correlation between geologic units that otherwise look very much the same and are a valuable tool in figuring out the age of a formation. Lots of detailed work goes into discerning the differences between small fossils that are difficult to the untrained or out practice.

23 to 30 million year old clam

The Pysht Formation is a marine unit on the north side of the Olympic Peninsula. The exact age is not well refined. Nesbitt, E.A.Martin, R.A.Carroll, N.P., and Grieff, J. (2010) have been working these fossils and others on the north Olympic Peninsula coast as well as magnetic signature and have placed the Pysht Formation on the order of 22 to 33 million year. As some key whale fossils have been found in the Pysht, the age of the formation is a big deal for whale evolution. 

Besides fossils, the Pysht Formation presents routine problems for the Washington State Department of Transportation. Large landslides and earth movement have broken across bedding plains within the siltstone and mudstone of the formation. These slides pose ongoing problems on State Highway 112 between Clallam Bay and Neah Bay. This formation is partly responsible for the slow twisty road when heading to the extreme northwest corner of the state. There are a number of landslides that will humble geologist that assess landslides. The fresh slide scarps cutting through the formation provide a chance to examine the ancient marine life that existed off the coast of North America prior to this chunk of sea floor being accreted to the continental margin.

The next day I came across a few more fossils in the similar aged Quimper Sandstone on the west shore of the Quimper Peninsula on the east side of Discovery Bay. The Quimper Peninsula is the peninsula on which Port Townsend is located. Most of the peninsula is glacial and other non bedrock units, but towards the south portion a variety of rocks are exposed not only along the shore but on the highland areas as well suggesting a structure of some sort. The Quimper Sandstone is much harder than the Pysht Formation, and is not so prone to large landslides. In this case good news for slope stability compared to the Pysht Formation.

Mollusk in Quimper Sandstone

The Quimper Sandstone also contains ample large concretions much like the concretions on the east shore of Marrowstone Island marrowstone-island-geology-trip.

Concretion in Quimper Sandstone

Friday, September 7, 2012

Star Light Swim in Hood Canal

It has been warm even on the Olympic Peninsula. I wrapped up yesterday's ventures on the Olympic Peninsula by camping on the shore of Hood Canal. After setting up camp and listening to Democrat speeches on the radio I had a very rare treat. I took a night swim in the warm waters of Hood Canal. The water temperature felt close to 70 as was the air temperature after a day in the 80s. I swam out far enough to get a good look at the jagged edge of the Olympic Mountains crest against the starry sky.
Been off line more days than not lately so posting has been limited. More when time and connection permit. 

Wednesday, September 5, 2012

The Palouse River Leaves Its Valley

As noted previously when I stumbled on Mullan Road, I was looking for the spot where the Palouse River leaves its old valley and takes an abrupt turn through a deep narrow slot of a canyon on its way to Palouse Falls and the on to the Snake River. Easy enough to spot on Google Earth.

The sharp left turn of the solid blue arrows marks the spot where the Palouse River leaves its old valley for the Palouse Canyon.
Palouse River Routes
Upstream of the abrupt turn in the river, the Palouse is a meandering river in its valley passing through scab land stripped of its soil by the massive Missoula Floods. Irrigated fields line the valley bottom and are used to augment the scant feed the scab land grazing provides.  

Palouse River Valley with irrigate fields next to the river. The foreground is a gravel bar from the Ice Age floods.

The flood waters completely filled the valley and surged south across a plateau between the Palouse River and the Snake River carving deep holes into the joint sets within the underlying Columbia River Basalt Group. When the flood receded the Palouse remained within one of those deep channels leaving its former valley as a mostly dry coulee.
The old river valley, now Washtucna Coulee
The valley floor is filled with sand and gravel from the flood at this point

Spot where the Palouse leaves the valley/coulee
The former route of Mullan Road passed just to the right of the low area.

There were schemes to divert the Palouse River back into its old valley via a canal. A canal was started but never came close to completion. It would be possible on a topographic basis to dam the current canyon and spill water westward down the now dry coulee. I have found no reference as to that ever being considered. Perhaps the area potentially irrigated was too small or the sidewalls of the canyon would be not hold water very well. Regardless, the lower end of the old valley a bit west of Connell is now well irrigated with Columbia Basin water via the system from Grand Coulee Dam.