C6
OUTSIDE
East Oregonian
Saturday, February 16, 2019
FORMED BY LAVA
Wallowa County
is home to the
earth’s greatest
volcanic eruption
By ELLEN MORRIS
BISHOP
EO Media Group
Wallowa County is a land
of superlatives. Le Gore Lake
is the highest in Oregon. Hells
Canyon is North America’s
deepest gorge.
And there is another, and
more global feather in its cap.
It is the place that unleashed
the Earth’s greatest known,
mapped, lava flow. Ever. This
volcanic eruption, 16.3 mil-
lion years ago, produced 9,500
cubic miles of basalt — enough
to build a wall a mile high and
a mile wide around the entire
continental United States.
What’s more, the county court-
house — and a lot of other
places in Wallowa County —
are built from the ashy, glassy
products of this eruption. We
know them as Bowlby Stone.
The basalt lavas of this
greatest of all lava flows
known on Earth is called the
Wapshilla Ridge Flow, named
for its excellent exposures on
the massive ridge between the
Snake and Salmon Rivers on
the Idaho side of Hells Can-
yon. This huge flow was part
of the Columbia River basalts
— lavas that form much of our
landscape.
The explosive, ashy tuff that
would become Bowlby Stone,
erupted at the same time from
the same batch of magma. The
link between the Bowlby Stone
tuff and the huge Wapshilla
Ridge lava flows was first rec-
ognized last year by a team
of geologists Klarissa Davis,
John Wolff, and Owen Neill of
Washington State University,
along with a colleague from
the University of Auckland in
New Zealand.
About 16.3 million years
ago what is now the Wallowa
Mountains and Zumwalt Prai-
rie were a lowland of marshes,
lakes, and rivers. There were
no Wallowa Mountains, no
Hells Canyon. Things looked
more like a soggy version of
Kansas.
The Wapshilla Ridge basalt
flow was really a continu-
ous series of flows and erup-
tions. The volcanic vent sys-
tem was more than 60 miles
long. Lava-gushing fissures
extended through today’s Wal-
lowas to Hells Canyon and
beyond. Intense eruptions
lasted more than 300 years
(perhaps as long as 1,000
years) and slathered 60,000
square miles of Oregon, Wash-
ington, and Idaho in lavas
averaging more than 100 yards
thick. Additional eruptions
may have continued for at least
Ellen Morris Bishop/Wallowa County Chieftain
Large holes left in the solidified Wapshilla Ridge basalt exposed in a road cut along the Imnaha Highway
attest to the huge amount of carbon dioxide and sulfur-rich gas brought to the surface by this greatest
of all known lava flows. Hot water and steam interacting with the iron-rich tuff produced the red and
yellow oxidized iron minerals in the soil above the basalt.
another 90,000 years. It was
the greatest of all the Colum-
bia River basalt flows, and the
most voluminous eruption yet
documented and mapped on
Earth.
One vent — or “dike” for
the Wapshilla Ridge Flow —
a 30-foot wide swath of basalt
that cuts through the much
older granites — is exposed in
the Wallowas just east of Max-
well Lake. Studies by Oregon
State University’s Heather L.
Petcovic determined that this
one vent alone gushed almost a
cubic mile of basalt per day for
10 years.
But now we’ve learned that
the Wapshilla eruptions were
much more than just basalt
flows. WSU geologists Kla-
rissa Davis, John Wolfe, and
colleagues found that much of
Zumwalt Prairie, from Crow
Creek to Camp Creek, was also
a site of major eruptions.
The Zumwalt Prairie erup-
tions were very, very explosive.
If you stick a red-hot poker
into water you get an instant
burst of steam and boiling
water. The same thing happens
on a much larger scale when
red-hot lava rising from deep
in the earth encounters lakes
and saturated ground near the
surface. Water boils. Steam
explodes. Hell breaks loose.
Geologists call this a “hydro-
volcanic eruption.”
When Wapshilla eruptions
began on Zumwalt, steam and
churning, boiling water liter-
ally tore the rising lava into
fragments and flung the whole
mess skyward. Some lava
chilled so quickly that it liter-
ally became glass rather than
basalt. Much of the fragmented
lava erupted at Zumwalt
reacted with water to become
an oxidized red-yellow clay-
rich ash.
This seething mixture of
gooey volcanic ash, shards
of volcanic glass, and roiling
steam, was so hot that when
it finally landed the particles
welded together into a solid
mass of soft, porous rock.
Geologists call this kind of
rock tuff. In Wallowa County
it’s known as Bowlby Stone.
The volcanic hysterics
that produced the Bowlby
Stone occurred multiple times
throughout centuries. Con-
sequently, there are multiple
Bowlby Stone-type deposits
that vary in colors, textures,
and composition. You can
find the welded tuff of Wap-
shilla Ridge eruptions along
Crow Creek, the Imnaha High-
way, and near Marr Flat. Ashy
deposits on Ruby Peak, and
a long-lost quarry site up the
Lostine River, where the stones
that compose the Lostine Tav-
ern, Lostine School and Cole-
man and Chrisman bank build-
ing in Wallowa originated, may
be remnants of those eruptions.
Not only did the Wapshilla
Ridge flow change the land-
scape. It also probably changed
the Earth’s climate.
The global climate of
about 15-17 million years ago,
known as the Miocene Climac-
tic Optimum, was somewhat
warmer than today. It coin-
cides closely with the entire
period, 14 to 16.7 million years
ago when most of the car-
bon-dioxide-rich
Columbia
River basalts erupted.
But at precisely the time
of the Wapshilla Ridge erup-
tions, the global climate cooled
by a degree or two. The gases
in Wapshilla Ridge lavas were
especially rich in sulfur. Davis
and Wolff determined this by
analyzing the gas trapped in
tiny bubbles within mineral
grains in the Bowlby Stone
tuffs. They calculated that the
Wapshilla Ridge Flow erup-
tions released about 300 billion
tons of sulfur dioxide into the
atmosphere, along with partic-
ulates. “This would have been
devastating regionally because
of the acid-rain effect from the
eruption,” Wolff said.
When a large quantity
of sulfur is injected into the
atmosphere, it blocks sunlight,
producing cooler global tem-
peratures. And so, the erup-
tion of the globe’s mightiest
lava flow here in what would
become Wallowa County, not
only changed the landscape,
but likely cooled the planet for
a brief time as well. “It had a
global effect on temperatures,
but not drastic enough to start
killing things, or if it did, it
did not kill enough of them to
affect the fossil record,” Wolff
noted.
The next time you are at
the Wallowa County Court-
house, or any of the many
other grayish stone buildings
here, take time to look, really
look, at a block of the Bowlby
Stone. Look at its textures —
elongated blobs of bark basal-
tic glass encased in a fabric
of welded gray ash. In most
blocks you can see a subtle pat-
tern that tells you which way
the wind was blowing as the
ash cloud came to rest. The
greatest known, mapped and
analyzed basalt eruption of
all time is right there in front
of your nose and at your fin-
gertips. No wonder Wallowa
County is such a powerfully
special place!
Snow day for a fisherman
By LUKE OVGARD
For the East Oregonian
Oregon is as beautiful and
varied as any state — perhaps
more than any other state. From
the salt marshes of the Tillamook
Bay to the rugged mountains and
canyonlands of the Wallowas;
from waterfalls in Silverton to
dense rainforest in Roseburg;
from the high desert hot springs
of the Oregon Outback to the
rapidly growing urbanity of the
Willamette Valley, we truly have
something for everyone.
While us Eastern Oregonians
miss out on the coast, smog and
long commutes, we do get some-
thing the valley dwellers don’t:
snow.
The powdery white stuff
comes in buckets out east, and
we have a love-hate relationship
with it. Sure, it provides much
needed snowpack to keep the
rolling hills and sage flats green
— OK, vaguely yellowish —
during the heat of summer, but
it can be dangerous in and of its
own right.
It can cause unsafe road con-
ditions, collapsing roofs and
flooding when it finally melts
off.
An inch of powder might
bring glimpses of the apocalypse
in Portland, but in places like
Klamath Falls, Lakeview, Pend-
leton, Burns and Baker City, it
takes a lot of snow to interrupt
daily life.
For that reason, we don’t
mind it. We may not love it, but
we understand its value.
Still, most high desert resi-
dents don’t go around begging
for the crystalline flakes, either.
Only one group of people prays
almost nightly for a frigid blan-
ket: students.
Snow problem
What began as sitting in
front of the radio or television
at six o’clock in the morning has
become checking the school dis-
trict Facebook page or waiting
for automated calls or text mes-
sages, but the average Oregon
kid still holds his or her breath
every morning he or she can see
it in the air outside the front door.
That same kid chants “Please”
over and over again, maybe as
a quiet prayer, maybe just for
the heck of it. Regardless, the
child sits there hoping for those
two words that bring children
as much joy as almost anything
else not containing sugar: “snow
day”.
As a teacher, everyone
expects me to carry out the
same ritual, hoping and praying
Jack Frost leaves a present too
large for plows to unwrap before
morning light.
But in all honesty, I don’t.
I love my job. Yes, some of
you other teachers out there may
roll your eyes a little, but I do.
I don’t always love every sin-
gle day of my job, but more days
than not, I feel fulfilled.
What doesn’t make me feel
fulfilled is a snow day. What am
I going to do on a snow day?
My hobbies are limited to
fishing and writing about fishing.
If I’m feeling especially unim-
pressive, I might add “reading,”
“traveling,” and “food” to my list
of hobbies, but that’s only when
I’m trying to sound sophisticated
on an online dating profile.
In reality, if I can’t fish, and
I don’t currently have a Prison
Break: Season One-caliber show
to binge watch on Netflix while
I eat my feelings, I’d rather be
working.
Don’t say ice fishing is an
option because in most of Ore-
gon, it really isn’t. Rarely does it
stay cold enough for long enough
to hit the hard water, at least
within an hour or so of any pop-
ulation center.
Roads
We do get snow days from
time to time.
I don’t hate them, but fellow
teachers worn thin by the ins and
outs of teaching: don’t hate me
for saying that.
The odd snow day isn’t all
bad, especially given that I only
had four days off in February,
so the added boost in relaxation
time was nice — until I got bored
out of my mind.
The two places I considered
fishing that weren’t frozen solid
were both several hours away,
but one has a steep boat ramp
that I’ve learned my lesson about
going down in heavy snow, and
the other happens to be right
where the plows decide to pile
snow when freakish, overnight
storms hit.
So here I sit, looking into the
whitewash and wistfully longing
for warmer days where I can get
off work, put on boots or waders
and head to the water.
As teachers, we have to sac-
rifice for our students’ success
and happiness, and if that means
sitting at home, bored out of my
gourd, then I’ll make the sacri-
fice and take a day off work. For
the kids.
———
Read more at caughtovgard.
com; Follow on Instagram and
Fishbrain @lukeovgard; Con-
tact luke.ovgard@gmail.com.