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    This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 United States License.
    Northwest Geology Field Trips, by Dave Tucker, is licensed under a Creative Commons Attribution-Noncommercial- Share Alike 3.0 United States License. You can use what you find here, repost it with attribution to the author, "remix" it for your own purposes, but may not use it with the intent of making money off of it.

    EDUCATORS: Please feel free to use anything you find here that is useful to your mission educating people about Earth science. E-mail me if it would help to have a larger or higher-resolution version of any of the images. tuckerd at geol dot wwu dot edu

Dickerman Mountain geology guide posted

Hi friends! Remember me?

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Stacked lava flows below the summit of  Dickerman Mountain. Click to enlarge.

A new geology field guide has been posted on this website. This one gives you something to do while you huff and puff your way up through the 45-million-year-old Barlow Pass Volcanics on the Dickerman Mountain Trail. The mountain rises above the South Fork Stillaguamish Valley, and is reached by the Mountain Loop Highway east of Verlot and Granite Falls. The trail is a steep mother, gaining 4000′ in just over 4 miles. The summit gives spectacular views into the Monte Cristo area peaks and Glacier Peak. I hiked the trail on July 3, 2016 with my friends Charlie and Scott Linneman. The views weren’t great due to clouds, but I got to examine some North Cascades rocks I wasn’t familiar with. The story is online, here.

Book Presentation in Edmonds September 14

I will be giving a talk about my book, Geology Underfoot in Western Washington on September 14 in Edmonds.

7 PM

Edmonds Senior Center

220 Railroad Ave.

 On the waterfront in Edmonds, directly across the street from the AmTrak station. There is some off-street parking at the Center, and there is elevator access. This is the montly meeting of the Ice Age floods Institute. Free and open to the public.

I will have copies for sale, $24. Also copies of the cover poster, $15. See you there!

Dave

 

New Geology hiking guide published on this website: Ridley Creek Trail, Mount Baker

Link to Ridley Creek Trail geology guide:

https://nwgeology.wordpress.com/the-fieldtrips/ridley-creek-trail-geology-guide/

Foot bridge over the Middle Fork

Foot bridge over the Middle Fork

Ridley Creek Trail begins at the end of the Middle Fork Nooksack Road on the southwest flank of Mount Baker. The trail accesses the heather meadows of Mazama Park and on to Park Butte Lookout. Along the way see forested latest Pleistocene moraines, glacial till from Canada complete with quartzite pebbles from the Rocky Mountains, limestone, lahar and ash deposits, a close up of the Cathedral Crag lava that predates Mount Baker, and finally, great views of Baker, the Black Buttes, and that enigmatic slice of the mantle, the Twin Sisters Range. Read the geology guide here.  Enjoy!

Dave Tucker

Guided geology field trip to Schreibers Meadow cinder cone

The NCI field trip to Schreibers Meadow cinder cone is booked up.

MBVRC WILL OFFER A VERSION OF THIS TRIP LATER IN THE SUMMER. PLEASE STAY TUNED to the MBVRC blog: mbvrc.wordpress.com.

Dave Tucker

Mount Baker Volcano Research Center subscription website

The bushwack up to the cinder cone rim. Click to enlarge. The bushwack up to the cinder cone rim. Click to enlarge.

North Cascades Institute is offering a guided geology field trip to the 9500-year-old Schreibers Meadow cinder cone on the south flank of Mount Baker. The trip will be led by MBVRC’s Dave Tucker. The date is July 6th, and costs $95. Register at the NCI website:

http://ncascades.org/signup/programs/volcanoes-legacy-in-cinder-cones-and-crater-lakes

The Schreibers cone is the only one in the Mount Baker volcanic field. It is located in old growth forest at 3500 feet elevation in Schreibers Meadow, just 1/2 mile from the end of the road. The trip will walk a short distance along the Park Butte/Railroad Grade trail, then veer off cross country (huckleberry meadow and some ponds) before the final 130′ climb up a steep forested slope to the crater rim. We’ll walk down to the soggy shores of the two crater lakes, and up to the opposite rim. After…

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Nooksack River landslide near Deming- Update #2

Red line marks scarp of Feb 21 landslide. A later, undated slide is outlined in green. The second slide send brown soil over the top of the earlier clayey slide.

Red line marks scarp of Feb 21 landslide. A later, undated slide is outlined in green. The second slide sent brown soil over the top of the earlier clayey slide. Click to enlarge any image.

Thursday I visited the toe of the February 21 Clay Banks landslide on the Nooksack River, in company with Scott Linneman (landslide geomorphologist at WWU Geology) and John Thompson, a geologist with Whatcom County Natural Resources. If you haven’t been following this story, please visit Dan McShane’s blog post for the background to the story including some fine maps and photos, and my original post from February 22, the day after the landslide. Dan has also posted a great set of old maps and LiDAR showing changes at the Clay Banks as the river changes position. The landslide occurred just at midnight Friday February 21; you can see the sudden radical, short-lived drop in the river discharge graph below (recorded at the river gage a mile downstream at Cedarville). Click link to annotated You Tube video.

The Nooksack River gage at Cedarville (Nugents Corner) recorded a brief but sharp drop in discharge while the landslide dammed the river.

The Nooksack River gage at Cedarville (Nugents Corner) recorded a very brief but sharp drop in discharge (from ~2500 to 400 cfs) while the landslide dammed the river. Click to enlarge.

Annotated Google Earth image, with corrected location of 2-21 landslide and new river channel at the toe. Click o enlarge any image.

Annotated Google Earth image, with corrected location of 2-21 landslide and new river channel at the toe. Click to enlarge any image.

The Clay Banks are a steep bluff of Pleistocene glacial clay around 100 feet high on the south side of the river about 1.8 river miles upstream of the Nugents Corner bridge. The landslide bit deeply into only the upper half of the bluff, leaving a prominent bench hanging above the river. There is landslide debris on the bench, but most of it appears to have flowed over the bench, down the bottom of the bluff and into the river.

Shaky split log spans a side channel.

Shaky split log spans a side channel.

We crossed a shaky foot log across a narrow side channel to get to the big gravel bar on the north side of the river, and then walked 350 yards to the river side directly opposite the landslide toe. The landslide began in a layer of glacial clay a few meters above a prominent alluvial bed called the Deming Sand. If there is a stratigraphic layer at this level in the Clay Banks that contributed to this landslide it was not apparent using a high power spotting scope.

The toe of the landslide consists of large blocks of clay.

The toe of the landslide consists of large blocks of clay.

The river is still ponded against the landslide toe which protrudes into the river for 200 feet or so from the south bank. The river has cut through the outermost edge of the landslide toe. The river drains the partial impoundment by racing through a 60-foot-wide (19 m, measured with a laser range finder) gap. We couldn’t measure the river depth, but know it was 5 feet right up against the bank we were standing on, and 10 feet or more may be a reasonable guess. The landslide toe consists of car-sized, or maybe even garage-sized, clay blocks, and rests on the surface of a gravel bar; the bar gravel is exposed beneath the debris. At the time of the landslide, the river was closely beneath the high bluff, and the gravel bar we now see beneath the toe was part of the one we were on. The river then cut a new channel around the outer edge of the deposit, isolating the bar gravel beneath the toe from the gravel bar on the north side of the new channel. We found a single, angular clay block lying on the north side side of the channel, and a number of rounded ones. We figure the angular one (see photo below) was tossed laterally out of the landslide toe. It hadn’t been rounded by river flow, so is almost certainly right where it landed at around 12AM Friday 2-21-2014. You can see the same block in Dan McShane’s post, though when he visited the river bank was a few feet furthe away. This block is direct evidence that the river is continuing to cut outward and remove the bar on the north shore. This block will probably tumble into the river in the next few days.

Angular clay block marks extreme outer margin of the landslide toe. River has cut a new channel between this block and the rest of the landslide.

Angular clay block marks extreme outer margin of the landslide toe. River has cut a new channel between this block and the rest of the landslide.

The surface of the landslide toe is covered with large clay blocks. These sit on topo of a pre-landslide gravel bar.

The surface of the landslide toe is covered with large clay blocks. These sit on topo of a pre-landslide gravel bar.

The river makes an end run around the toe, and then cuts sharply south and runs directly into  the base of the bluff below the landslide. This is certainly undercutting the base of the Clay Bank, setting the stage for another collapse, perhaps involving the entire bluff height rather than the upper half.

Among our observations is that there has been a second, much smaller landslide in the same place. We don’t know when this occurred, but it sent darker material over the bank and down onto the southern margin of the Feb 21 toe. Compare the photo taken by Dan McShane on the morning of Feb 22 with the one I took today (Feb 27). The center of the 12-hour old scarp in his photos is now deeper where the 2-?? landslide collapsed. Also in the photos, note the toppled trees that rode the slide over bank.

The Clay Banks extend another 1/4 mile or so upriver and 1/2 mile downriver from the 2-21 landslide. Earth movements have been happening here at various scales for decades, and are likely to continue long into the future.

ACCESS NOTE: All access is over private land, so you are dependent on reports from authorized visitors. Sorry. Don’t even try to get there yourself. It is difficult to see the Clay Banks scarp from anywhere on the north side of the river. You may get a glimpse from the Deming Road somewhere in the first half mile after it branches off Mount Baker Highway a bit east of Nugents Corner. However, you will be 7/10 of a mile away, and for sure can’t see the river or the landslide toe.

‘Mounds’ between Sedro Woolley and Burlington

Hello Dave,
I’ve always wondered about the large “mounds”/irregularities to the East of I-5 between the Skagit and Samish rivers… They’re pretty hard to miss. How did they form, and what exactly are they?

Carston, May 29, 2013

Burlington Hill looking south from Cook Road. Click to enlarge any image.

Burlington Hill looking south from Cook Road. Click to enlarge any image.

In response to Carston,  my geologist friend Doug McKeever and I finally got around to making the jaunt south to look at these conspicuous wooded hills that rise out of the Skagit River flood plain. The greenschist and phyllite is quite interesting and very easy to get to. The driving trip is a worthwhile short detour of just a few miles when you are passing by on I-5. On a nice day the view from one of the hills over the flats is wonderful. The field trip is posted here.

Silvery phyllite and greenschist.

Silvery phyllite and greenschist on Burltingon Hill.

Giant Cairn in the Wharf Roundabout, Bellingham Washington

Some guy in a funny hat looks at the giant rock cairn in the roundabout. Hey! Wait I think I know that guy! Where're the cats?

Some guy in a funny hat looks at the giant rock cairn in the roundabout. Hey! Wait I think I know that guy! Where are the cats?

A number of Bellingham people have written me for a geological description of the 12′ rock cairn in the middle of the new roundabout at Wharf, State, Forest, and Boulevard. An article appeared in Dean Kahn’s Dec. 22 column in the Bellingham Herald; prior to that, I sent a photo and a brief notice to David B. Williams’ GeologyWriter.com blog. The 13-foot-tall stack of 4 boulders sits in the new roundabout at the south edge of downtown Bellingham. Shrubs have been planted around the cairn, but they are still spindly and short so it is still approachable on foot.

“NAME THE STACK” CONTEST! Scroll down.

The lowest two, and the uppermost, boulders are dunite from the Olivine Corporation’s Sven Larsen Quarry on the north flank of the Twin Sisters Range west of Mount Baker. (48° 44.640′ N , 122° 0.345′ W.) The stone second from the top is serpentinite. It also came from the quarry. The stones were supplied by Princess Jade, a stone-supply company in Everson Washington. Get up close enough to see the smooth highlights on the serpentinite boulder, polished by Princess Jade prior to installation. The 8-mile-long Twin Sisters Range is a narrow slab of mantle dunite, among the largest in the world, faulted upward into the crust during plate collisions, and exposed by erosion.

The dunite boulders feature tiny black chromite crystals surrounded by olivine.

The dunite boulders feature tiny black chromite crystals surrounded by olivine.

Dunite is a dense crystalline rock. By definition, it consists of around 90% olivine crystals; the remainderis pyroxene and chromite. Dunite is believed to be the residue left behind when basaltic magma forms in the mantle, typically deep in subduction zones. Water carried into the mantle via the subducted ocean plate (the ‘slab’) lowers the melting point of the mantle, generating basaltic melt. The lower density basalt magma rises upward through the mantle taking lighter minerals such as silica along for the ride, leaving behind the denser minerals – olivine and pyroxene. Serpentinite is a low-temperature metamorphic rock formed when water enters the molecular structure of ultramafic rocks such as dunite. Hydrated olivine becomes a different mineral, serpentine.

Polished highlights on the softer serpentinite boulder.

Polished highlights on the softer serpentinite boulder.

The City of Bellingham had a choice of two designs incorporating the large boulders. The stack won out over the other possibility, scattering the rocks on the ground. Bellingham’s mayor, Kelli Linville, said “The landscaping we chose reflects the natural beauty of our area. Since cairns are traditionally used to help people find their way, a cairn is an appropriate part of the landscape at this important crossroads in our community.” (Bellingham Herald, Dec 22, 2013). According to Sam Shipp, the project engineer at Bellingham’s Public Works Department, the cairn option helps protect drivers from the glare from oncoming headlights and directs drivers’ vision toward other vehicles approaching from the left inside the roundabout, as well as providing an aesthetic component.

Dunite is very dense, about 3.3 grams/cubic cm. Serpentinite is around 2.7 g/cc. Contrast that with basalt (2.8-3 g/cc), andesite (2.5-2.8) and granite 2.6-2.7). The largest stone, the one on the bottom, weighs around 15.5 tons. The two in the middle are 8.5 tons each, and the little one on top is about 3.5 tons. The four stones are held upright by a central steel rod sunk into a concrete base. The project cost $75,000.

OK. “NAME THE STACK” CONTEST! Let’s name that stack o’ rocks! Submit your suggestions via comment and I’ll forward them to the City via my very special confidential connection.

Geology Field Trip gift certificates from MBVRC

Cross country trip to Schreibers Cinder Cone.

Cross-country trip to Schreibers Cinder Cone.

Mount Baker Volcano Research Center is offering gift certificates for geology field trips.  These make great gifts for your geophile friends and relatives. The cost  is $75 (the usual cost of a one day guided trip, including van transport) and can be applied to any field trip offered by MBVRC. This year there are plans to offer  trips to lowland sites in Northwest Washington in the late winter/early spring. In the summer, trips will go to locations around Mount Baker , and a multi-day trip to Mount St. Helens is in the early planning stages.

To purchase a gift certificate, send an email or letter to MBVRC. Include  the name of the person the certificate is for, as well as your mailing address. You may send payment via check payable to ‘MBVRC’ to  708 13th St, Bellingham, or use the MBVRC PayPal account – the account code is this email address:

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You will receive a nicely printed gift certificate in the mail. Field trip fees beyond expenses go to the MBVRC research and education fund. To see brief descriptions of some  past geology field trips, scroll down here: http://mbvrc.wordpress.com/field-trips/

Geology field trip offered near Monroe, Washington

NWGS logo

THIS TRIP IS FULL.

The Northwest Geological Society’s annual fall field trip will visit the Cadman High Rock Quarry near Monroe, Washington. This is a large rock and sand quarry with outstanding exposures of the Volcanic Rocks of Mt. Persis and 107 ka river deposits of the Whidbey Formation with a glacial till below it. We will observe striking evidence of sub-glacial flow and the full range of Vashon glacial units, and look at faults and liquefaction related to the Southern Whidbey Island Fault (SWIF). The field trip will involve walking several miles through the quarry.

Saturday, November 16, 2013
9:45am–3:00 pm
Leader: Bruce Stoker, Earth Systems and High Rock Quarry Personnel
Location: Cadman High Rock Quarry
Address: 19221 High Rock Road, Monroe, WA. 98272

Please RSVP by sending an email to Kathleen.goodman@amec.com.  For important trip information and a trip description, visit the NWGS website:   http://nwgs.org/calendar/NWGS_Fall_2013_FT_Announcement.pdf for details on times, parking, attire, and most important, post-quarry recap at the Grange Cafe in Duvall.  Cost is $10 payable at the quarry.

Advance registration is required for official head count for the quarry. NO WALK-UPS, PLEASE.
Deadline:Thursday, November 14.
Payment: Please bring your $10 payment (cash or check made out to NWGS, no credit or debit cards) to the field
trip for collection at the quarry office.
This is a one-stop field trip. Transportation will not be provided. We will meet at the Cadman High Rock Quarry office (address and a link to directions above).The trip will start with a required 20-minute safety training session in the quarry office. Please do not be late, as the course is required for all to enter the quarry.
The field trip will involve walking several miles through the quarry.

Sign up for geology trip- Ptarmigan Ridge, Mount Baker

We'll learn how platey jointing and columnar jointing forms.

We’ll learn how platy jointing and columnar jointing form.

The view west from the Ptarmigan Ridge Trail.

The view west from the Ptarmigan Ridge Trail.

Dave Tucker will lead a one-day geology hike on Ptarmigan Ridge, near the Mount Baker Ski Area. The trip is organized by North Cascades Institute.

September 29, all day. $95 includes trip guide and transport from Glacier Ranger Station.

This hike will explore the gorgeous volcanic landscape on the east side of Mount Baker- Kulshan caldera ash flow tuff, post-caldera rhyolite domes, Table Mountain and Ptarmigan Ridge lava flows, volcanic ash deposits (Baker and Crater Lake). Mount Shuksan is just east of us, so we can also discuss terrane accretion. The hike is above tree line on the Ptarmigan Ridge Trail, elevation gain is around 500 feet, total round trip distance of 10 miles but probably less. There are 6 spaces left for this trip. The September 28 trip is full.

NCI website for the trip: http://ncascades.org/signup/programs/mount-baker-the-story-of-volcanoes-ii-ph

Registration: http://ncascades.org/signup/programs/mount-baker-the-story-of-volcanoes-ii-ph/program-registration

Questions? Contact NCI, or Dave Tucker directly.

email address to send reports and photos. I'll credit you.

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