Posted by: magmatist | November 14, 2014

Mount Baker earthquakes in November

Two small earthquakes have occurred near Mount Baker in November, the second and third detected in 2014. Magnitudes were 1.9 and 1.1. Though small, they were still among the largest earthquakes at Cascade volcanoes in the past month. They are not considered anything other than normal.


1. On November 5th, there was an M 1.9 event just after midnight at or near the terminus of the Thunder Glacier, 4 km west of Mount Baker’s summit. Though small, this is still among the largest earthquakes recorded at the volcano in the past 9 years (see graph at the link above- scroll down there in the right margin’s list. Pacific Northwest Seismic Center’s report page: Note the uncertainty in depth of this seismic event, 31.61 km vs. horizontal error, only 0.6 km. The waveforms are here:  Note that the top two graphs are from the nearest seismic stations, MBW (2.8 km distant) and SHUK, near the Mount Baker ski area, 16.1 km distant.

2. On November 12th, an M 1.1 earthquake was centered beneath the right valley wall of Park Creek on the east flank, nearly 10 km from the summit. Pacific Northwest Seismic Center’s report page: The event was reported at 4.5 km depth, but note the uncertainty in depth of this seismic event is less than the other, merely 15.87 km. The horizontal error is nearly 1 km. The waveforms are here:  MBW (15.8 km distant) and SHUK, near the Mount Baker ski area, 12.6 km distant.

In contrast, only one small earthquake was reported in 2013 (and that was likely due to blasting), and one each in 2012 and 2011.

For a comparison of relative seismicity at Cascade volcanoes over the past 30 days, visit this page:



Posted by: magmatist | October 12, 2014


Whatcom County Library System is sponsoring 3 Mount Baker talks.


Deming Library, October 18, 4 PM.

Ferndale Library, October 21, 7 PM.

Everson Library, November 8, 3 PM.


The talk presents the volcanic history of Mount Baker: eruptions, collapses, and the hazards this active volcano poses. The state of monitoring at the volcano will be discussed. The likely volcanic future and the potential for impacts on Whatcom-Skagit communities will close out the presentation.

Only 40,000 years old, the Mount Baker cone is about the same age as Mount St. Helens. Very little was known of its volcanic history until extensive geologic mapping by USGS geologists Wes Hildreth and Kevin Scott began in the mid 1990s. We now know that Mount Baker is but the youngest in a series of volcanoes in the immediate area extending back over 1,000,000 years. Other volcanoes in the Baker group include: two calderas that each erupted roughly 200 times as much ash as Mount Saint Helens did in 1980; a subglacial cone; and a number of once-sizable stratovolcanoes, most now eroded to nubs. Collapse of the volcano’s southwestern slope sent a large mudflow, or lahar, down the Middle Fork Nooksack River into the lowlands of Whatcom County and possibly as far as the Fraser River. Field studies continue to describe the post-glacial eruptive history. The newest, soon-to-be published research has revealed the patterns of ash deposits erupted from Mount Baker.

The presentations are given either by Dave Tucker , a research associate in the geology department at Western Washington University, or Doug McKeever, geology professor at Whatcom Community College. Both are board members of MBVRC, and have carried out considerable field work on the volcano.

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Posted by: magmatist | July 24, 2014

Mount Baker geothermal potential study published

A geothermal potential study for Washington State, just published by the Division of Geology and Earth Resources of the state’s Department of Natural Resources, includes discussion of the Mount Baker area.. The Geothermal Favorability Model of Washington State, by D. E. Boschmann, J. L. Czajkowski, and J. D. Bowman (2014) is available on line:

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The Mount Baker portion of the study focused on the Baker Hot Spring area between Mount Baker and Baker Lake Reservoir on the east side of the mountain, as that is where the only surface expression of heat is known. There is also some speculation on the potential within the Kulshan caldera, between the volcano and Mount Shuksan.

Study summary:  Geographic Information System (GIS) modeling of statewide heat, permeability, and infrastructure data, including volcanic centers, faults, earthquakes, temperature-gradient wells, thermal springs, young silicic intrusive rocks, and transmission lines produced layers showing relative geothermal favorability in Washington State. Regional modeling like this is one way to reduce costs in geothermal exploration by helping to more precisely locate areas worthy of additional research.

The entire discussion from the Baker section follows. The upshot is that while there may be considerable potential, infrastructure costs would be very high, and developement would be limited because the one of the most likely areas, within the Kulshan caldera, lies in the protected Mount Baker wilderness area.

The Mount Baker volcano and surrounding area have received considerable attention due to the presence of thermal features and young volcanic centers. Exploration activities have included detailed geologic mapping, spring sampling, geophysical surveys, soil mercury measurements, and limited temperature gradient drilling (Korosec, 1984). Chemical geothermometry of Baker Hot Springs suggests that reservoir equilibrium temperature of this system may reach as high as 150° to 170°C (Korosec, 1984). In 1983, a 140 – meter-deep (460 ft) temperature-gradient well was drilled near Baker Hot Springs. It had a bottomhole temperature of 48°C and a geothermal gradient between 200° and 309°C/km (Czajkowski and others, 2014c). However, this gradient is likely affected by hot spring circulation and may not represent a typical background value for the area.

Our modeled geothermal resource potential values near the Mount Baker/Kulshan Caldera suggest elevated resource potential, most notably in the area surrounding Kulshan Caldera (Fig. 6A) where no geothermal exploration has been performed to date. Kulshan Caldera is an oblate ~13-square-mile Pleistocene volcanic center located ~3.7 miles to the northeast of Mount Baker. Several Pleistocene andesite to rhyodacite vents and domes are located within the margins of the caldera, and late Pliocene to Pleistocene silicic intrusions are common in the surrounding area (Hildreth and others, 2003). However, our geothermal favorability model suggests that exploration for geothermal resources in this area would be unfavorable once transmission line proximity and elevation restrictions are considered (Fig. 6B). Further, much of the area with elevated resource potential lies within the Mount Baker Wilderness Area and is likely protected from any type of development.


Dear friends,

photo from INternational Porters Protection Project

photo from International Porters Protection Group

A MBVRC science team will head to Mount Baker’s Sherman Crater for the annual round of gas sample collection this coming Monday-Tuesday [July 28-29].

We are looking for a few day-hikers who can help get our science and some of our personal gear up to base camp. A load of 10-20 pounds per person is anticipated. The planned camp location is along the Railroad Grade Trail at about 5700′, in the last grove of trees. This is below the treeless climbers camp at the head of the Railroad Grade [Sandy Camp], and there is good trail all the way. The one way distance along the Park Butte and Railroad Grade trails  is about 3.5 miles, with 2400′ vertical gain. If you haven’t done this hike, it is spectacular as it runs along the crest of the razor-sharp 19th Century Railroad Grade moraine with great views of the Easton Glacier terminus and Mount Baker rising above. I will walk with volunteers if I can so I can point out some of the great geology along the way.

Please email right away if you’d like to join us:  research ‘at’

Please let us know where you would be coming from, how fit you are, and if you can drive other volunteers. You would need a pack big enough to carry your own day hike stuff plus a tent, rope, bag of food, or a box of science gear.

The climbing team will rendezvous in Bellingham at 10 AM, probably won’t get out of town until around 11. We can arrange to meet volunteer load carriers at the rendezvous, or elsewhere along the way, or at the Schreibers trailhead. We can figure out carpooling for the porters, who will be out for the day hike only.

If the weather is bad on Monday [forecast is currently good] we will bump our approach hike to Tuesday. Please let us know if you are available that day, just in case.

Many thanks,

Dave Tucker, MBVRC

Posted by: magmatist | June 30, 2014

Guided geology field trip to Park Butte, Mount Baker

Baker and the Black Buttes from the meadows below Park Butte.

Baker and the Black Buttes from the meadows below Park Butte.

The trip is full. You can still sign up (no fee) to be on the cancellation list.

MBVRC is offering a guided geology hike to Park Butte, near the south flank of Mount Baker. Registration information is below. The trip is oriented toward the general public with an interest in geology, but no previous geologic background is necessary.

Wednesday, August 20, 8:30 am to 6:00 pm.

The 7-to-8 mile round trip hike offers great views of Mount Baker’s glacier-clad south slope, the glacially-gutted Black Buttes volcano, and  the Twin Sisters range. We will see deposits left by glacier outburst floods, a Mount Baker lahar, the early Holocene Sulphur Creek lava, a rare type of lava for the Baker volcanic center (olivine basalt at Cathedral Crag), several volcanic ash layers, Pleistocene lake deposits, and some of the oldest rock known in the North Cascades (Yellow Aster gneiss in the Bell Pass Melange).  At Tarn Plateau we will see an orphan lava that is between Black Buttes and Mount Baker in age. We can visit one of the few remaining fire lookouts in the area on Park Butte, time and weather permitting. Hiking begins at the trail head in Schreibers Meadow.

Several layers of volcanic ash can be seen in trail cuts.

Several layers of volcanic ash can be seen in trail cuts.

The trip will be led by  Doug McKeever, geology professor (emeritus) at Whatcom Community College, assisted by Dave Tucker, adjunct faculty at Western Washington University. Both are board members of Mount Baker Volcano Research Center and have published on Mount Baker volcanic geology.

The cost is $75 person.This  includes transportation,  field trip pamphlet, and the services of your cheerful guides. $50 for those who attended a previous MBVRC field trip in 2014. Proceeds go to the MBVRC research and education fund. Van transportation is provided from our rendezvous in Bellingham, with an additional pickup spot near Sedro Woolley for folks coming from south of Bellingham.

Additional information: The Schreibers Meadow trailhead is at 3,350 feet and Park Butte lookout is at 5,450 feet. The grade is moderate and the trail is rocky in places but no scrambling is involved. You will need to bring a small backpack with lunch and water, plus clothing and footwear suitable for changeable mountain weather conditions. The trip is suitable for teens and up. The trip goes rain or shine.

REGISTRATION: MBVRC field trips fill quickly. Please reserve your spot via email to:

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You will receive payment and rendezvous instructions. This trip is limited to the first 20 paid persons. Your payment is a tax-deductible charitable contribution.

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:

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 we return to the vans we’ll  examine scoria (the fragments of frozen lava that erupted from the cinder cone), and also the lava that followed after the scoria. Some of that lava entered a glacial lake that occupied the Baker River valley back in the day, and solidified underwater, and we’ll look at that lava, too. This is about the only place in the Cascades with easy access to subaqueous lava.

The Schreibers Meadow cinder cone, south flank of Mount Baker, seen from the north.. Click to enlarge.

The Schreibers Meadow cinder cone, south flank of Mount Baker, seen from the north. Click to enlarge.

No geologic training is needed for this fun hike and geo-tour. The cross country travel is not very difficult but you should be in at least a modicum of physical condition to manage the steep but short scramble through the bushes to the crater rim- and back down. Please direct all inquiries to North Cascades Institute.

Posted by: magmatist | March 29, 2014

2013 MBVRC financial statement

MBVRC is a 501 (C) 3 nonprofit. We depend on financial support from our friends and the fine folks who attend our educational presentations and join our field trips. The board of directors wishes to let you know where our funding comes from and where it goes. Here is the 2013 MBVRC financial statement. Thanks to all who donated, joined a field trip, or bought a shirt or a poster. This statement will be filed with the Washington State Secretary of State’s office and the IRS.

The 2013 MBVRC financail statement. Click to enlarge

The 2013 MBVRC financial statement. Click to enlarge


An excel spreadsheet is attached>

MBVRC financial statement

Our net income in 2013 was $683.27. Our largest expense was the research grant program: we awarded ($2751). T-shirt sales were our largest income source, with donations a close second. We had only one field trip in 2013, to the Baker River in early June. We plan more for 2014.

You can purchase a gift certificate for any MBVRC field trip. They cost $75; all you need to do is shoot an email (address below) and we’ll get one to you. Full info is here.

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this is not a link

Posted by: magmatist | March 7, 2014

Geology field trip April 12

West Beach, Deception Pass State Park consists of eroded Pleistocene glacial deposits. Fidalgo Island, across Deception Pass, consists of sea floor rocks accreted to the margin of North America.

West Beach, Deception Pass State Park consists of eroded Pleistocene glacial deposits. Fidalgo Island, across Deception Pass, consists of sea floor rocks accreted to the margin of North America.

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Register now for MBVRC’s April 12th guided geology field trip, oriented towards a general audience. The all-day trip is a fundraiser for our research and grant program. We will visit a number of outcrops at Deception Pass, Mount Erie, and the Chuckanut Coast. The trip leader is Scott Babcock, geology professor at Western Washington University and coauthor of ‘Hiking Guide to Washington Geology’ (originally published as ‘Hiking Washington’s Geology’). Scott has led geology trips for general audiences in many parts of the world. MBVRC gift certificates may be redeemed for this or any MBVRC field trip.

TRIP COST: the trip is open to each person who makes a minimum $75 tax-deductible donation to MBVRC, until the vans are full. MBVRC will provide van transport and handouts.                   

Ribbon chert deposited in the deep ocean is now exposed at Rosario Head.

Ribbon chert deposited in the deep ocean is now exposed at Rosario Head.

DESCRIPTION: Some really interesting geology is revealed by the landforms and rock outcrops found in the lowlands and foothills of Northwest Washington.  Most of the landscape and deposits of this area are the legacy of the advance of glaciers during the last Ice Age between 21,000 and 13,000 years ago.  However there are also scattered outcrops of bedrock that are millions of years old.  We will begin the trip with some of the youngest glacial deposits on Whidbey Island and work our way back to Bellingham through spectacular exposures of the older bedrock at Deception Pass, Mount Erie and elsewhere on Fidalgo Island, and finish up with younger rocks along Chuckanut Drive. We will inspect sea floor sedimentary rocks, pillow basalts, remnants of an oceanic magma chamber, and 60-million year old flood plain deposits of the Chuckanut Formation. There will be a series of short walks.  The longest will be about a quarter mile along the beach at West Beach in Deception Pass State Park.  The most strenuous will be 1/8 mile to Rosario Head (70′ elevation gain).  There will be other stops at Deception Pass, Mount Erie, and along Chuckanut.

Tilted marine sedimentary rocks at Deception Pass.

Tilted marine sedimentary rocks at Deception Pass.

We will travel in two rental vans, starting from Bellingham; there will be a couple of pick up points along the way if you join us from points south. The trip is open to all ages, and no prior geology is required. However, a basic understanding of plate tectonics, in particular subduction and terrane accretion will be useful.

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this is not a link

Mount Erie rocks were intruded beneath an oceanic volcanic island. Views from the top are spectacular.

Mount Erie rocks were intruded beneath an oceanic volcanic island before accretion to the North America. Views from the top are spectacular. Hope for good weather!

REGISTRATION: Registration is through advance donation to MBVRC. The trip is limited to the first 26 people making payment.

1. Send an email to MBVRC stating your intention to attend. Please put ‘field trip’ in the subject line of your message. You will receive payment information, and can pay through PayPal or personal check. If you have a gift certificate, let us know.

2. Trip confirmation is in order of contribution received.

MORE FIELD TRIPS will be offered later in the year, including Mount Baker hikes. Stay informed by taking out an email subscription to this blog using the subscription box at right.

The Spring 2014 Adventures NW.

The Spring 2014 Adventures NW.

Pick up* a free copy of Adventures NW magazine to find a fictional account of a near-future eruption at Mount Baker. The story was written by Dave Tucker, and contains a number of photos by John Scurlock, as well as a magnificently photoshopped rendition of Baker in eruption. Special insider info for MBVRC blog-o-philes: the eruption cloud is taken from a photo of Semeru (Java); the Baker view is a photo by John D’Onofrio (publisher/editor/chief cook and bottle washer at Adventures NW) taken from out in the San Juans. A photo essay will appear on the magazine’s website next week.

Bear in mind that the eruption story is one of only several possible scenarios for a Baker eruption. This one is based on the 6600 year old ‘BA’ tephra eruption, the largest from Sherman Crater in the geologic record. A lahar is generated (read the story to learn where it goes and what it does). Certainly a number of other Baker variations could be told. Much depends on wind direction, height and volume of the eruption plume, whether or not a volcanic landslide and lahar develop and in what drainage(s).

*Adventures NW is a free outdoors magazine published in Bellingham. Find it at “hundreds of locations region-wide, throughout Whatcom, Skagit, San Juan, and Island counties, at select spots in Snohomish, King and Pierce counties, and in Leavenworth, the Methow Valley, Spokane and Wenatchee. The magazine is also available at all REI locations in Washington and Oregon as well as at numerous locations in the Vancouver, BC metro area and through races and events and at visitor centers.”

Posted by: magmatist | February 27, 2014

Large plumes at Sherman Crater today

Feb. 27, 2014 gas plumes. Photo by Chris Farrow, Big Lake, Washington

Feb. 27, 2014 gas plumes. Photo by Chris Farrow, Big Lake, Washington

Atmospheric conditions were right this morning to see a sizable gas plume rising from Sherman Crater and rising over 1000 feet. There have not been many good plume shows this winter. The plume is about 99% steam; the remainder of the gas is mostly CO2 and H2S, which are ultimately derived from hot magmatic rocks at an unknown depth below the volcano. The photo was taken by Chris Farrow, who lives near Big Lake, east of Mount Vernon. Thanks, Chris.

Posted by: magmatist | February 7, 2014

Eruption simulation links repaired

The Mount Baker eruption simulation links have been updated; you will find them here:

This model simulates a repeat of the largest eruption at Baker that is preserved in the geologic record as it would behave today, using the latest NOAA wind data. This data is updated 3 times per day.  This models the 6600 year old “BA ash eruption”, with a duration of 6 hours and with a plume reaching 8 km into the atmosphere (about 5 km above the summit of Mount Baker). It is instructive to return to this page as weather changes in the Baker area- where might ash fall on any given day?

Ricardo Escobar. All photos courtesy R. Escobar. Click to enlarge any image.

Ricardo Escobar. All photos courtesy R. Escobar. Click to enlarge any image.

Here is the final report from Mount Baker Volcano Research Center’s 2013 research grantees. Ricardo Escobar is a geology graduate student at Western Washington University under the supervision of Dr. Susan DeBari; he hails from Los Angeles. Ricardo’s tale of his adventures in the field follow, a classic account of field work in the Baker area, and his description of his project. Like May Sas and Ian Delaney, he received $667 towards his thesis study of the origin of andesite lava in the Mount Baker volcanic field (MBVF). Scroll down here to read Ricardo’s research proposal.

Ricardo’s project may seem superficially similar to May’s. But, while May is studying the enigmatic origin of high-magnesium andesites, which have some geochemical signature indicating at least some mantle influence, Ricardo is focusing on the far more voluminous and typical MBVF andesites that have a ‘normal’ Mg composition and are generally believed to differentiate in the crust.

Help support MBVRC’s research fund. It’s easy to contribute right now via paypal, or by mail. All contributions are tax-deductible.

Petrogenesis of intermediate magmas at Mount Baker volcano, northern Cascade arc. Ricardo Escobar, WWU Geology

Ricardo will sample the circled lava units. Map from Hildreth, 2003.

Ricardo will sample the circled lava units. Map from Hildreth, 2003.

Several studies have been conducted to better understand the petrologic processes occurring beneath the Mount Baker volcanic field, but none have been aimed at discerning the origin of true intermediate (54-62 wt. % SiO2) magmas (andesites). Considering andesitic lavas are the most voluminous component of flows in the Mount Baker volcanic field, it is important to gain insight on how these magmas originated. Previously, Moore and DeBari (2012) conducted a study on the primitive magmas (basalts) of the Mount Baker volcanic field, in which they identified three primitive magma types: calc-alkaline basalt, high-Mg andesite and MORB-like low K tholeiite. Most recently, Gross (2012) studied the most differentiated magmas (dacites) of the Mount Baker volcanic field and was unable to constrain the Nooksack Falls dacite with a primitive magma identified by Moore and DeBari (2012). Set up as an ideal framework, I propose to evaluate the relationship(s) intermediate magmas have with the most primitive and differentiated magmas found in the Mount Baker volcanic field. Specifically, the goal is to understand what roles magma mixing and crystal fractionation play in generating the intermediate magmas and possibly constrain the parent-less Nooksack falls dacite.

In order to ensure the collection of true intermediate magmas of the Mount Baker volcanic field, I used Hildreth et al.’s (2003) foundational study, which is the most comprehensive study of Mount Baker volcanic field lava flows, as a starting point. The major element dataset of Hildreth et al. (2003) allowed me to construct geochemical variation diagrams for selecting true intermediate magmas. Four lava flows were selected: andesite of Dobbs Cleaver, andesite of Dobbs Creek, andesite of Coleman Pinnacle and andesite of Swift Creek.

D. Tuckers assists with sampling at the none-too-prominent Dobbs Cleaver andesite.

D. Tuckers assists with sampling at the none-too-prominent Dobbs Cleaver andesite.

During the months of August and September, I made several trips to the Mount Baker area to collect rock samples from four flows: Dobbs Cleaver, Dobbs Creek, Swift Creek and Coleman Pinnacle (see the map above). Following field work, I cut billets (blocks of rock about the size of a microscope slide) of each sample for professional thin section preparation by Vancouver Petrographics. I then powdered splits from the remaining rock samples for XRF and ICP-MS analyses, which have now been completed- results will appear in my thesis following comparison and interpretation. Funds received from MBVRC have been used to cover the cost of thin sections ($625) and a portion of the XRF chemical analyses carried out at Washington State University ($42).

Jungle-covered andesite of Dobbs Creek is a thick flow guarded by steep slopes and brush.

Jungle-covered andesite of Dobbs Creek is a thick flow guarded by steep slopes and brush.

Accessibility to the target lava flows is impossible throughout most of the year as they are under snow cover. My field work took place in August and September 2013. The unpaved Wells Creek Road, off the Mount Baker Highway, accesses Dobbs Cleaver and Dobbs Creek on Cougar Divide. Despite dense vegetation and complete absence of trails, I collected seven samples of the andesite of Dobbs Cleaver on August 13, 2013 with the assistance of Dave Tucker and about 30 gazillion mosquitos. I intended to collect samples of the remaining flows over the course of a few days. Taking Wells Creek Road once more on August 25, 2013, I ventured on a steep cross-country hike to gain access to the andesite of Dobbs Creek. Again, due to the difficulties of hiking and spotting outcrops in dense vegetation, only 5 samples were collected on that day.

A large clot of crystals in Coleman Pinnacle andesite.

A large clot of crystals in Coleman Pinnacle andesite.

After camping off a forest road, early the next morning I took the Ptarmigan Ridge trail, at Artist Point, toward the andesite of Coleman Pinnacle. Due to intense fog, rain and dropping temperatures throughout the day I only managed to collect 4 samples. Earlier that week, the forecast had predicted clear skies for the days I planned to be out in the field so as one can imagine I was ill-prepared. Having been completely soaked and experiencing quivers throughout my body I decided to retreat and head home. My next attempt to collect samples from andesite of Swift Creek on August 31, 2013. Two trailheads give access to these remote outcrops on the floor of Swift Creek. On this day I, along with a field assistant, started on the Lake Ann trailhead near Artist Point. To our dismay, the lower channel of Swift Creek below Fourth of July Creek was inaccessible from the trail. Steep cliff drops over 20m high confronted us at every turn. Fortunately, one creek that feeds into Swift Creek contained an exposure that appeared identical to Swift Creek andesites sampled by Hildreth et al. (2003) and so two samples were collected. Two weeks later, on September 13, 2013, I decided to enter Swift Creek from the south side and was much more successful. To access the flows I had to hike and wade upstream, which results in less mileage and more time. I managed to collect three samples, totaling five samples from the andesite of Swift Creek flow. Discontented with my andesite of Coleman Pinnacle collection, I ventured out once more on September 26, 2013 to collect a couple more samples. Fortunately, the weather was promising and my assistant and I successfully collected two more samples from andesite of Coleman Pinnacle, totaling at 6 samples. Though several complications arose throughout my sample collecting, I managed to collect a total of 23 samples.

Beautiful thin columns on the bank of deepest darkest Swift Creek.

Beautiful thin columns on the bank of deepest darkest Swift Creek. Now these are worth the effort!

Over the past few months I prepared my rock samples for XRF and ICP-MS analyses, which requires a lengthy and tedious process. The process includes breaking down rock to chips and finally to a powder. Once the powders have been made, they are mixed with a flux, allowing the powder to melt at a much lower temperature, and made into a glass bead. The beads are then analyzed at the GeoAnalytical Lab at Washington State University (WSU). While preparing my samples for XRF and ICP-MS analyses, I sent billets of each sample to Vancouver Petrographics for professional thin sections. I am now conducting microscopic analyses with the thin sections as I await for my XRF and ICP-MS data from WSU. From petrographic analyses I will select minerals for further investigation with an electron microprobe to understand physical properties of the magma chamber(s) beneath the Mount Baker volcanic field. Once I receive the data from the XRF and ICP-MS analyses I can begin to construct diagrams and models for explaining the petrogenesis of intermediate magmas at the Mount Baker volcanic field.

May on Ptarmigan Ridge, east of Mount Baker.

May on Ptarmigan Ridge, east flank of Mount Baker.

MBVRC provides grants to support geologic research on Mount Baker. Reports from grant recipients are periodically posted so you, who are the principal contributors to our research fund, will know how the money is being spent. Here is a report from May Sas, one of our three 2013 grant recipients.  May is a geology grad student at Western Washington University. Last spring we posted the proposals from our 2013 grantees; scroll down  here to read May’s full study plan. In late December we posted a final report from Ian Delaney. A report from Ricardo Escobar, the third award winner, will come your way soon.

It’s really easy to contribute via paypal, or by mail. All contributions are tax-deductible.

High-Magnesium andesites from the northern Cascade Arc: Using mineral chemistry to distinguish between hypotheses for their origin

by May Sas, WWU.


Geologic map of Mount Baker volcanic field, modified after Hildreth et al. (2003), showing May’s study areas in the insets. (A) Glacier Creek andesite (agc). (B) Tarn Plateau basaltic-andesite (atp).

The origin of high-Mg andesites (HMAs) poses a fundamental geochemical paradox given their unusually high Mg# (‘magnesium number’, or the ratio of Mg to the sum of Mg and Fe), indicating equilibrium with mantle olivine, and at the same time their overall andesitic SiO2 contents, which are more typical of crustal magmas. Trace element chemistry of HMAs is also distinctive; they exhibit a steep rare earth element (REE) pattern with high La/Yb ratios, notable depletion in heavy REE, and Ni and Cr enrichment. In this project I am trying to discern between variable hypotheses for the origin of HMAs in the northern Cascade Arc using rocks from Mount Baker and Glacier Peak.

Because samples from lavas in the Mount Baker volcanic field have been collected during previous studies and whole-rock chemistry completed, this project represents an excellent opportunity to explore the information carried in large crystals (phenocrysts) to answer questions of andesite magma origin. An investigation of phenocryst geochemistry, in combination with whole-rock geochemical data and modeling, will allow me to test previous hypotheses in order to constrain the origin and evolution of these magmas prior to eruption. My methods include analysis of crystal textures (chiefly disequilibrium textures), mineral chemistry (major, minor, trace element), and modeling.

Progress Report: Grant funding from the Mount Baker Volcano Research Center, totaling $667, was used toward electron microprobe (EMP) analysis completed at University of Washington in September 2013. Data collection during this session included major and minor element concentration in olivine, clinopyroxene, and plagioclase mineral phases. Three different high-Mg flows were analyzed, Glacier Peak’s Lightning Creek basaltic andesite and Mount Baker’s Tarn Plateau basaltic andesite and Glacier Creek andesite. Over 15 crystals of each phase have been examined per unit. These data are being worked on and reviewed in detail, and will be used to constrain crucial magmatic conditions as well as provide the first clue regarding the origin of these controversial lava flows.

Image of a 100μ thick (that’s 0.004 inch) plagioclase crystal as seen with the optical microscope. Please click to enlarge this beautiful tiny crystal.

Additional work that has been completed includes preparation of 100 micron(μm) thick sections of selected samples, extensive petrographic examination for identification of mineral phases and textural relationships, and extensive scanning electron microscope imaging of ideal crystals using the back-scatter electron (SEM-BSE) technique. Future work, in addition to data processing, includes more EMP analysis, specifically deciphering oxide chemistry which will be used to derive magma oxygen fugacity levels (ƒO2). Laser ablation inductively-coupled plasma mass spectrometry (LA-ICPMS) will follow EMP work, and will be used to determine trace element concentrations in the selected samples to calculate parental magma compositions. Finally, modeling will be used to conclude the probable source of these HMAs by amalgamating all of the constraints, such as H2O contents and ƒO2 conditions, in addition to mineral and whole rock major, minor, and trace element concentrations.

Posted by: magmatist | January 2, 2014

Welcome new subscribers

Aerial photo by John Scurlock.

Baker pops a champagne cork. Aerial photo by John Scurlock.

Happy New Year, everyone! The MBVRC blog has really taken off this year. Nearly half of all subscribers joined us in 2013. There were over 32,500 page views in 2013, double the tally from 2012. Readers were particularly interested in the several reports on the Middle Fork Nooksack landslide-induced debris flows back in May and June. The daily Mount Baker eruption simulations generated by the USGS Ash3D computer model are also a big hit (see the ‘monitoring’ page for the link).

If you haven’t yet, spend some time poking around the various page tabs at the top of the webpage.

Watch for a post in the coming days summarizing our nonprofit organization’s activities over the past year, and the financial statement. We depend on donations from the public to keep our research fund growing, and you have a right to see how we spend our money.

We plan an expanded field trip schedule this year, including some to the Salish lowlands in late winter/spring. Not specifically Mount Baker oriented, but fun geology regardless.

Two Mount Baker eruption history and hazard presentations are currently on the schedule:

January 14- Skagit Audubon Club meets at Bayview State Park’s Padilla Bay Interpretive Center, 7 PM.

February 1- Oak Harbor, at the Sound Waters annual symposium. 1:15.

Both presentations will be by Dave Tucker.

Posted by: magmatist | December 29, 2013

Kulshan caldera ash discovered in Eastern Washington

The arrow at left points to the tephra deposit. Photo courtesy Nick Pearce.

The arrow at left points to the tephra deposit. Photo courtesy Nick Pearce.

A new deposit of the 1.15 million-year-old ash that erupted during collapse of the Kulshan caldera has been discovered near Washtucna in eastern Washington, 350 km (220 miles) southeast of the source. The Kulshan caldera is on the east margin of the Mount Baker volcanic field. The ash is called the Lake Tapps tephra; the lake is near Sumner, the town east of Tacoma where the 20-30 cm ash deposit was first discovered; it was originally described in a 1980 paper by John Westgate and his colleagues, when the source eruption was yet unknown. A 3-cm-thickness of the tephra was also found in Frigid Creek, 90 km west of Sumner in Mason County

The discovery was made by Nick Pearce and his colleagues from Aberystwyth University (Wales) during research into Mount St. Helens ash deposits. They discovered a 15 cm thick ash layer in the Palouse Loess (thick, long-lived windblown deposits). The sample site was already known from earlier paleomagnetic work to be around 1.2 Ma, close to the age of the caldera eruption. Nick reports that the ash was sampled and chemically analyzed. It was found to be an excellent match to the Lake Tapps tephra, which was shown by Wes Hildreth to be the same as the intracaldera deposits.  Nick was sent pumice and ash samples from within the caldera to further substantiate his work.

Detail of the 15-cm-thick Lake Tapps (Kulshan caldera) tephra at Washtucna. Nick Pearce photo.

Detail of the 15-cm-thick Lake Tapps (Kulshan caldera) tephra at Washtucna. Nick Pearce photo.

The new find suggests that the caldera tephra is distributed further and more thickly to the east or southeast, rather than to the south. Perhaps other deposits will be discovered by alert geologists in the future. We’ll post more details of this research as it progresses, and references when they are published.


Hildreth, W., 1996, Kulshan Caldera: a Quaternary subglacial caldera in the North Cascades, Washington: Geological Society of America Bulletin, v. 108, p. 786-793.

J.A. Westgate, D.J. Easterbrook, N Naeser, R Carson, 1980, Lake Tapps tephra: An early Pleistocene stratigraphic marker in the Puget Lowland, Washington. Quaternary Research, v. 28, p. 340-355.

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