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Brushbuffalo
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PostThu Oct 27, 2016 11:58 am 
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Dave Tucker asked if I could do one last field check of a chapter on his upcoming book on the geology of Mount Baker.  I had had the flu (despite a flu shot!) until a couple of days before, but I wanted to get this in before new snow made the field check unlikely.  So I hiked the Scott Paul Trail (clockwise) on October 24. Although there was a foot or more of sloppy snow at 5,000' most of the places I needed to check were visible, if some only barely. There was such a sharp snow line that there was virtually no snow  below 4,500'.  Snowshoes would have been handy (left 'em in the truck of course), but thanks to some trailblazers from the previous day, I had it pretty easy. The usually busy parking area was empty and I didn't see anyone all day on this cloudy Monday.
Geologic highlights: Sulphur Creek lava flow and the Scheibers Meadows cinder cone; Schreibers Meadow lahar; Ridley Creek lahar; glacial outburst flood boulders; fragmental volcanic flank deposits; four different tephras (Mazama layer O, Mt. Baker OP and BA, Schreibers Meadow SC); both Mt. Baker and Black Buttes lava; lateral and terminal moraines.  I wasn't able to photograph all of these on this hike due to new snow.

The loop is about 8.3 miles (according to my GPS)with 1880 feet of ascent and while the seasonal bridges across Rocky Creek have been removed,  both crossings were mere rock hops. I watched the ceiling progressively lower during my hike, and although I had no rain, it poured most of the way home. 

Just made it.  wink.gif

Here are some images with a few explanatory comments. Sorry about the mediocre quality. The unskilled photographer did the best he could in the lighting available. This is a spectacular hike on a clear day! Go then....

Appropriately-named Rocky Creek. Note the concrete block, part of a fancy suspension bridge built here in the 1980s that was destroyed by repeated "pineapple express" storms dumping heavy rain on winter snow packs.  Also occasional outburst floods from Easton Glacier ravage the channels of this braided stream. These floods transport lots of glacially-eroded lava blocks, rounding them in the process. The load of boulders plugged the drainage and diverted Rocky Creek into a formerly abandoned channel to the west (next image).
Appropriately-named Rocky Creek. Note the concrete block, part of a fancy suspension bridge built here in the 1980s that was destroyed by repeated "pineapple express" storms dumping heavy rain on winter snow packs.  Also occasional outburst floods from Easton Glacier ravage the channels of this braided stream. These floods transport lots of glacially-eroded lava blocks, rounding them in the process. The load of boulders plugged the drainage and diverted Rocky Creek into a formerly abandoned channel to the west (next image).
This is where the seasonal bridge crossing Rocky Creek has been located for the past few summers. It was an easy rock hop on this day.
This is where the seasonal bridge crossing Rocky Creek has been located for the past few summers. It was an easy rock hop on this day.
The trail climbs a series of switchbacks, where the trailside deposits are unconsolidated silt, sand and boulders. Much of this is Pleistocene glacial till, but it is mantled by the Rocky Creek volcaniclastic fan deposit.  As the massive continental ice sheet receded from the valleys and lower slopes of Mount Baker, eruptions sent lava flows down the upper flanks of the still-glaciated volcano. Floods produced by interaction of ice and lava resulted in debris that was deposited as a massive fan.
The trail climbs a series of switchbacks, where the trailside deposits are unconsolidated silt, sand and boulders. Much of this is Pleistocene glacial till, but it is mantled by the Rocky Creek volcaniclastic fan deposit.  As the massive continental ice sheet receded from the valleys and lower slopes of Mount Baker, eruptions sent lava flows down the upper flanks of the still-glaciated volcano. Floods produced by interaction of ice and lava resulted in debris that was deposited as a massive fan.
Looking south from the switchbacks across a fork of Rocky Creek, you can glimpse remnants of the fan plastered against the steep slopes of Survey Point. The stream trenched downward into the easily eroded fan deposits.
Looking south from the switchbacks across a fork of Rocky Creek, you can glimpse remnants of the fan plastered against the steep slopes of Survey Point. The stream trenched downward into the easily eroded fan deposits.
Sometimes interesting features are barely noticeable unless we look carefully, as with this small-scale differential erosion along the trail.  Note how pebbles form a protective "cap" for sediment just below.
Sometimes interesting features are barely noticeable unless we look carefully, as with this small-scale differential erosion along the trail.  Note how pebbles form a protective "cap" for sediment just below.
Once past the upper junction of the Scott Paul and Park Butte trails,  you come to a forested ridge just past a small stream. This is a late Pleistocene lateral moraine from a much larger Easton Glacier. Note how this inner slope is stable and vegetated.
Once past the upper junction of the Scott Paul and Park Butte trails,  you come to a forested ridge just past a small stream. This is a late Pleistocene lateral moraine from a much larger Easton Glacier. Note how this inner slope is stable and vegetated.
Round the crest of the Railroad Grade moraine and behold the deglaciated valley of Rocky Creek. The inner margin of Railroad Grade stretches toward Mount Baker, and across the valley the parallel left-lateral moraine (Metcalf moraine) matches.  At its maximum recent extent in the 1800s, you would have stepped off the moraine onto the glacier here. The ice surface reached the crest of these  paired moraines ('rocks don't fall uphill':), filled the valley at  your feet, and reached nearly to the lower crossing of Rocky Creek. The high mound in the center of the valley is an eroded remnant of a Mt. Baker lava flow, almost completely covered by glacial till.  Note Colfax and Lincoln Peaks, highest remnants of the extinct Black Buttes volcano, to left of the lurking Mt. Baker and Sherman Peak. At far right is Crag View, consisting of  late Mt. Baker lavas. Clouds obscured all of these peaks ten minutes later.
Round the crest of the Railroad Grade moraine and behold the deglaciated valley of Rocky Creek. The inner margin of Railroad Grade stretches toward Mount Baker, and across the valley the parallel left-lateral moraine (Metcalf moraine) matches.  At its maximum recent extent in the 1800s, you would have stepped off the moraine onto the glacier here. The ice surface reached the crest of these  paired moraines ('rocks don't fall uphill'), filled the valley at  your feet, and reached nearly to the lower crossing of Rocky Creek. The high mound in the center of the valley is an eroded remnant of a Mt. Baker lava flow, almost completely covered by glacial till.  Note Colfax and Lincoln Peaks, highest remnants of the extinct Black Buttes volcano, to left of the lurking Mt. Baker and Sherman Peak. At far right is Crag View, consisting of  late Mt. Baker lavas. Clouds obscured all of these peaks ten minutes later.
The trail gradually descends on the inner side of the  right lateral moraine of the Easton Glacier to the upper crossing of Rocky Creek. If you think this should be the LEFT lateral moraine,  lateral moraines are designated based on a down-glacier view. This view is looking up-glacier.
The trail gradually descends on the inner side of the  right lateral moraine of the Easton Glacier to the upper crossing of Rocky Creek. If you think this should be the LEFT lateral moraine,  lateral moraines are designated based on a down-glacier view. This view is looking up-glacier.
Note how this slope is much more unstable-looking and sparsely vegetated compared to the late Pleistocene moraine.
Note how this slope is much more unstable-looking and sparsely vegetated compared to the late Pleistocene moraine.
Here is another view farther up the valley. Very unstable due to relatively short time since deposition(I would have been standing, or rather squished, under ice at this location only about a century ago).
Here is another view farther up the valley. Very unstable due to relatively short time since deposition(I would have been standing, or rather squished, under ice at this location only about a century ago).
Upper crossing of Rocky Creek. A seasonal suspension bridge is located here.
Upper crossing of Rocky Creek. A seasonal suspension bridge is located here.
Without bridge, the creek was a 3 foot step in these low water conditions.
Without bridge, the creek was a 3 foot step in these low water conditions.
FLASH BACK Here is the bridge as we hiked it on Sept. 10 of this year. Compare this late summer stream flow with that of a cool late October day ( previous image). Edit: I just noticed that the large brownish boulder had moved  a few feet between Sept. 10 and Oct. 24.  There must have been a lot of water recently to do that!
FLASH BACK Here is the bridge as we hiked it on Sept. 10 of this year. Compare this late summer stream flow with that of a cool late October day ( previous image). Edit: I just noticed that the large brownish boulder had moved  a few feet between Sept. 10 and Oct. 24.  There must have been a lot of water recently to do that!
Dave T. and I co-led a field trip for MBVRC on Sept. 10 to the terminus of the Easton Glacier. Fun thing for anyone but perhaps especially for non-climbers to safely step onto glacial ice!
Dave T. and I co-led a field trip for MBVRC on Sept. 10 to the terminus of the Easton Glacier. Fun thing for anyone but perhaps especially for non-climbers to safely step onto glacial ice!
A visit to the terminus leaves one sinking  ankle deep in saturated mud, the result of recent terminal recession.
A visit to the terminus leaves one sinking  ankle deep in saturated mud, the result of recent terminal recession.
Very recently deposited till from the Easton Glacier, the terminus of which has retreated about 300 yards in the past three years.The ridge is an end moraine and the ice is 300 yards beyond the  view in upper left.
Very recently deposited till from the Easton Glacier, the terminus of which has retreated about 300 yards in the past three years.The ridge is an end moraine and the ice is 300 yards beyond the  view in upper left.
Burned-out wreckage of a snow machine. I wonder what happened?
Burned-out wreckage of a snow machine. I wonder what happened?

BACK TO THE SCOTT PAUL HIKE ON OCT. 24:
A distinctive volcanic material found in the Rocky Creek/Easton Glacier valley is informally known as 'shermanite' due to its origin in Sherman Crater. It is white to light gray hydrothermally altered rock that at one time was perfectly good andesite. Sulphurous gases and acidic water associated with fumaroles in Sherman Crater chemically deteriorated the andesite to make weak clay minerals (kaolinite, alunite, and smectite) as well as pure very white opaline silica. Bright yellow sulphur crystals can be found in some shermanite blocks.
A distinctive volcanic material found in the Rocky Creek/Easton Glacier valley is informally known as 'shermanite' due to its origin in Sherman Crater. It is white to light gray hydrothermally altered rock that at one time was perfectly good andesite. Sulphurous gases and acidic water associated with fumaroles in Sherman Crater chemically deteriorated the andesite to make weak clay minerals (kaolinite, alunite, and smectite) as well as pure very white opaline silica. Bright yellow sulphur crystals can be found in some shermanite blocks.
The blocks tend to be weak and often decompose into piles of fragments. The blocks formed in  Sherman Crater due to chemical weathering and  most likely got here by being blasted out of the crater by steam-generated explosions (phreatic eruptions) onto the surface of the Easton Glacier, whose movement brought them downslope. Melting exposed the shermanite.  Smaller fragments are visible in trailside exposures at Schreibers Meadow carried there by a lahar (Schreibers Meadow lahar).
The blocks tend to be weak and often decompose into piles of fragments. The blocks formed in  Sherman Crater due to chemical weathering and  most likely got here by being blasted out of the crater by steam-generated explosions (phreatic eruptions) onto the surface of the Easton Glacier, whose movement brought them downslope. Melting exposed the shermanite.  Smaller fragments are visible in trailside exposures at Schreibers Meadow carried there by a lahar (Schreibers Meadow lahar).
The trail traverses Rocky Creek valley on its way to a climb to the crest of the Metcalf moraine.  To the north, you can see the terminus of the Easton Glacier.
The trail traverses Rocky Creek valley on its way to a climb to the crest of the Metcalf moraine.  To the north, you can see the terminus of the Easton Glacier.
From the crest of the Metcalf moraine look south to  sparsely forested Schreibers Meadow. It is the surface of a lava flow that came from the base of the Schreibers Meadow cinder cone about 9500 years ago.  The flow is clearly evident in the valley below, especially if you take the road to Blue Lake/Dock Butte trailhead, which directly crosses the very rough flow surface. The flow is NOT "rough" near the cinder cone due to being covered by a lahar.  In this view you can clearly see the summit crater of the cinder cone, which is the forested hill in the middle distance.
From the crest of the Metcalf moraine look south to  sparsely forested Schreibers Meadow. It is the surface of a lava flow that came from the base of the Schreibers Meadow cinder cone about 9500 years ago.  The flow is clearly evident in the valley below, especially if you take the road to Blue Lake/Dock Butte trailhead, which directly crosses the very rough flow surface. The flow is NOT "rough" near the cinder cone due to being covered by a lahar.  In this view you can clearly see the summit crater of the cinder cone, which is the forested hill in the middle distance.
From Metcalf moraine  a wall of gray cliffs poking out from the forest  across Rocky Creek is the lowest lava from Mount Baker on the south flank of the volcano.
From Metcalf moraine  a wall of gray cliffs poking out from the forest  across Rocky Creek is the lowest lava from Mount Baker on the south flank of the volcano.
The trail gradually ascends the outer slope of the Metcalf moraine.
The trail gradually ascends the outer slope of the Metcalf moraine.
I find it interesting that the inner slope of the Metcalf moraine is covered with young trees, while the equivalent slope on the Railroad Grade moraine is not treed (the trees in the middle are on till covering a bedrock knob). The difference is probably due to warmer west-facing exposure on Metcalf moraine. Park Butte with its wonderful  lookout in the distance.
I find it interesting that the inner slope of the Metcalf moraine is covered with young trees, while the equivalent slope on the Railroad Grade moraine is not treed (the trees in the middle are on till covering a bedrock knob). The difference is probably due to warmer west-facing exposure on Metcalf moraine. Park Butte with its wonderful  lookout in the distance.
Loomis Mountain on horizon, with Survey Point in front.
Loomis Mountain on horizon, with Survey Point in front.
At several places as you hike across the meadows near timberline, weaving in and out of minor drainages, you can see barren, bouldery mounds close to the trail. This is a terminal moraine from ice that lay between the Easton and Squak Glaciers.  Crag View is the prominent ridge in center. A[url=http://www.pbase.com/nolock/image/74122700/original]1912 photograph from Loomis Mountain[/url] showed ice at the position of this moraine. On this day the new snow cover and bad visibility made it hard to see the moraine clearly, but in at least one place boulders from the moraine have fallen right next to the trail. Here is the [url=https://mbvrc.files.wordpress.com/2012/09/146105105-bwkl3rrx-copy.jpg]same view as the 1912 photo linked above in 2012[/url] from Loomis Mountain.
At several places as you hike across the meadows near timberline, weaving in and out of minor drainages, you can see barren, bouldery mounds close to the trail. This is a terminal moraine from ice that lay between the Easton and Squak Glaciers.  Crag View is the prominent ridge in center. A1912 photograph from Loomis Mountain showed ice at the position of this moraine. On this day the new snow cover and bad visibility made it hard to see the moraine clearly, but in at least one place boulders from the moraine have fallen right next to the trail. Here is the same view as the 1912 photo linked above in 2012 from Loomis Mountain.
Tephra from the Schreibers Meadow cinder cone and Mount Baker is found in several places on the Scott Paul trail. In this view, below the saddle on the eastern part of the trail,    9500 yBP (Years Before Present) reddish scoria (SC from Schreibers Meadow cinder cone) is lowest, covered by a thin discontinuous  layer of tephra from Sherman Crater, where the pole tip is (OP , 6700 yBP), then on top is  gritty black ash known as BA (6600 yBP).  Abundant deposits of SC are easily seen in roadcuts along the last half mile of the road to the trailhead.
Tephra from the Schreibers Meadow cinder cone and Mount Baker is found in several places on the Scott Paul trail. In this view, below the saddle on the eastern part of the trail,    9500 yBP (Years Before Present) reddish scoria (SC from Schreibers Meadow cinder cone) is lowest, covered by a thin discontinuous  layer of tephra from Sherman Crater, where the pole tip is (OP , 6700 yBP), then on top is  gritty black ash known as BA (6600 yBP).  Abundant deposits of SC are easily seen in roadcuts along the last half mile of the road to the trailhead.
Beautiful old growth in the Hudsonian zone.
Beautiful old growth in the Hudsonian zone.
A final feature of geologic interest as one hikes the Scott Paul clockwise is this cliff above the trail about 1/2 mile below the saddle. The cliff is made of rock not from Mt. Baker but from the older, larger,more distant  Black Buttes volcano, which is chemically quite distinct compared to Baker lavas.  This one fooled me while doing my MS field work.
A final feature of geologic interest as one hikes the Scott Paul clockwise is this cliff above the trail about 1/2 mile below the saddle. The cliff is made of rock not from Mt. Baker but from the older, larger,more distant  Black Buttes volcano, which is chemically quite distinct compared to Baker lavas.  This one fooled me while doing my MS field work.

Dave Tucker's book will be useful for increasing your knowledge as you hike the trails on and near Mount Baker.  It should be released early in 2017. I will revise this last comment as soon as I learn the title and expected publication date.

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Passing rocks and trees like they were standing still
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monorail
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PostThu Oct 27, 2016 5:23 pm 
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This is fascinating; thanks for taking the time to share so much information! I'll look for the book when it comes out.  Do you know what the title will be?
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whitebark
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PostThu Oct 27, 2016 6:01 pm 
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Yes, fascinating geology ...thanks for posting this!
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gb
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PostThu Oct 27, 2016 6:41 pm 
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Thank you for the geology lesson. I've hiked the loop many times.
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RichP
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PostThu Oct 27, 2016 9:14 pm 
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Very informative report. Looking forward to the book.

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Without obsession, life is nothing. John Waters
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Brushbuffalo
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PostThu Oct 27, 2016 9:24 pm 
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monorail wrote:
I'll look for the book when it comes out.  Do you know what the title will be?

I emailed  Dave asking  if he had an official  title  yet and  when the  book would  be available.
He replied:
"Working title is “Mount Baker Geology Guide: Roads and Trails”. Or maybe        “Road and Trail Geology Guide to Mount Baker” or maybe “Doug and Dave’s Excellent Adventures”

Next summer [early?]."

Knowing a little bit about book publishing, it always seems to take longer than expected  ( kinda like building projects).

I really doubt  Dave will prefer the third title  dizzy.gif However, although it doesn't sound too academic, it would be fitting for us!

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Passing rocks and trees like they were standing still
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HitTheTrail
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PostFri Oct 28, 2016 11:50 am 
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Great TR up.gif I like the modularized photo/text format. It offers quick and easy reading/comprehension for slow guys like me. Keep it up.
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