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THE ASTORIAN • SATURDAY, FEBRUARY 26, 2022
SPORTS
Local equestrian team opens season
By GARY HENLEY
The Astorian
The fi rst Oregon High
School Equestrian Teams
competition of the year is in
the books, with riders and
their horses competing ear-
lier this month at the Yamhill
County f airgrounds.
It also served as the fi rst
meet of the season for the
Northwest district, which
includes Clatsop County’s
equestrian team, coached by
Brittany Israel.
Members of Israel’s team
include riders from Astoria,
Seaside and Warrenton high
schools.
Riders and horses from
Astoria include Alivia Rick-
enbach (two horses, “Ath-
ena” and “Sage”), Signe
Rickenbach (“Timber”) and
Eve Espelien (“Lewy”);
from Seaside, Alicia Cano
(“Moon”), Matthew Cano
(“Sailor”), Lindsey McCa-
rthy (“Cosmo”), McKenna
Roberts (“Jackson”), Oshi
Ward (“Flash” and “Goldie”)
and groomer Theia McCa-
Brittany Israel
Local riders from Astoria, Seaside and Warrenton make up this year’s local Oregon High School Equestrian team, in Yamhill for
their fi rst competition of the new season.
rthy. Warrenton has one
competitor with two horses,
Kaylie Poe (“Emma” and
“MoPoe”). Espelien is out
with a broken arm, suff ered
in basketball.
In the recent competition,
held Feb. 10 to Feb. 13, rid-
ers from St. Helens High
School won the overall team
results with 832 points, while
the Astoria, Seaside and War-
renton competitors combined
for 287.
H ighlights for the locals
included a strong perfor-
mance by Roberts and Jack-
son in Showmanship, as the
pair took second out of 20 rid-
ers. Alicia Cano, with Moon,
placed 10th, while McCarthy
and Cosmo came in 13th.
In the Working Pairs com-
petition, Cano and Moon
teamed with Alivia Ricken-
bach and Sage to place ninth
out of 15 pairs, as the rid-
ers from Seaside and Astoria
rode to “The Champion” by
Carrie Underwood.
In the 18-rider Keyhole
competition, Signe Ricken-
bach and Timber took 11th,
followed by Kaylie Poe and
MoPoe, 13th.
In Barrels, Ward and
Flash took third out of 26
riders. Ward and Flash also
came up winners in the Pole
Bending competition, with a
21.964, fi rst out of 23 riders.
Alivia Rickenbach and Ath-
ena placed eighth.
Rickenbach and Athena
also took eighth out of 24 rid-
ers in the Figure 8; and sis-
ters Alivia and Signe Rick-
enbach, riding Athena and
Timber, took fourth out of
18 teams in the Two-man
Birangle.
The Roberts and Jackson
pair was ninth out of 21 rid-
ers in Western; and Ward and
Flash took second in Sunday
Steer Daubing.
Three pairs took part in
“Grand Entry” riding, includ-
ing Alivia Rickenbach and
Athena carrying the Amer-
ican fl ag; Poe and Emma
with an Oregon High School
Equestrian Teams fl ag; and
Cano and Moon, represent-
ing Seaside.
Oregon sunstones shimmer with mysteries
By JULE GILFILLAN
Oregon Public Broadcasting
To many, the science of
geology can seem incompre-
hensibly technical and ach-
ingly slow. But when Emily
Cahoon started her doctoral
work in the fi eld, the volcanol-
ogist, geochemist and igne-
ous petrologist would uncover
a treasure trove of mysteries
that are as intriguing as they
are dazzling — literally.
Cahoon’s studies centered
on the Picture Gorge Basalt, a
north-central Oregon portion
of the much larger Columbia
River Basalt Group. These
vast basalt fl ows that erupted
some 16 to 17 million years
ago fl owed over a major por-
tion of the Pacifi c Northwest
and gave rise to some of the
region’s most epic landscapes
as well as our state gem, the
sunstone.
Columbia River basalts are
divided into sub-units based
on their location, age and geo-
chemistry. The Picture Gorge
Basalt, which Cahoon jok-
ingly refers to as “the runt”
of the Columbia River fl ood
basalt family because of its
smaller eruptive volume, was
fi rst identifi ed near John Day.
Through gathering rock sam-
ples and conducting geochem-
ical analysis, Cahoon hoped to
fi ll in some of the data gaps in
what distinguishes that partic-
ular sub-unit.
“We’re trying to under-
stand where they were erupt-
ing out of because the magma
that fed these eruptions was
basically the same body of
magma that feeds Yellow-
stone, you know, is under
Yellowstone National Park
today,” she said.
Looking for a novel
approach to the topic, Cahoon
wondered if the presence of
relatively large sunstone crys-
tals in Columbia River lava
fl ows might hold clues about
where the magma that fed
these basalt fl ows originated.
“That’s big because where
the actual magma chamber
was located during these erup-
tions is still very much a topic
of debate in the scientifi c com-
munity,” she said.
In 2016, Cahoon’s advi-
sor handed her a map from a
gemological publication with
an “X” on it, designating the
location of a sunstone mine
called the Ponderosa Mine.
The mine is located in remote
northern Harney County and
outside the boundaries of any
of the Columbia River fl ood
basalt areas. If the chemistry
of the lavas there matched the
ones Cahoon was analyzing,
her advisor told her, it might
mean some redrawing of the
Picture Gorge map area.
Gemstone opens door to
geologic discovery
Oregon’s state gemstone
is the sunstone. What makes
the stones unique is that they
contain copper, a metal that is
not normally found in these
feldspar crystals. The cop-
per inside the sunstone crys-
tals can lead to a dazzling
variety of colors from clear
to pink to red and even green
and teal. When the copper
fl ecks in some crystals show a
shimmery gold color, they’re
referred to as “schiller.”
Sunstone mining in Ore-
gon has been centered around
the tiny town of Plush, which
has a population around 60, in
south-central Oregon’s Lake
County. Geologists had long
assumed that the gemstones
occur there as a result of the
nearby Steens Mountain sub-
unit of the Columbia River
basalts. But because the “X”
on Cahoon’s map marked a
location outside the known
boundaries of the Steens
Mountain sub-unit, she won-
dered whether that long-stand-
ing assumption was correct.
“Where the Ponderosa
Mine is located has kind of
been a gap on geologic maps,”
she said, meaning it was not
inside any of the recognized
Columbia River basalt fl ow
areas. “So, the fi rst thing I
did was geochemical anal-
ysis (of the local rocks) and
determined that they’re actu-
ally part of the Picture Gorge
Basalt.”
The new fi ndings sug-
gested the Picture Gorge
Basalt was not only larger, but
also erupted earlier and for lon-
ger than previously thought.
“We used to have this kind
of conspicuous gap where
no (Columbia River basalt)
lava had been identifi ed, and
now we’re sitting on them,”
Cahoon said last August on a
visit to the Ponderosa Mine.
It got her thinking.
“So here at the Ponder-
osa Mine, this is the northern-
most location of where sun-
stones have been found,” she
said. “The rest of the mines
are about 80 miles south, close
to Steens Mountain, down in
the Plush area.”
Cahoon headed for the
sunstone mining area near
Plush to conduct the same
geochemical analysis on the
rocks there. What she found
upended the earlier assump-
tion that sunstones are con-
tained in lava fl ows associ-
ated with the Steens Mountain
sub-unit.
“Sure enough, those rocks
that host sunstones down in
Plush are also Picture Gorge
basalt and not Steens,” she
said.
Shiny objects
As fascinating as these rev-
elations were geologically,
Cahoon’s attention was drawn
to the shiny sunstones literally
lying on the ground under her
feet.
“I saw these sunstones and
was like ‘This is so cool!’ And
appsolutely
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for a geologist, gemstones
are one of those things that
every kid—” she stammers,
still excited by the memory.
“That’s kind of how you get
interested in geology.”
But for Cahoon, sunstones’
coolness factor had a deeper
signifi cance.
“Usually if it’s cool, some-
body’s looked at it, right?” she
said.
Cahoon was in for yet
another surprise.
“I remember, you know,
going back and digging
through some literature, going
on Google Scholar and try-
ing to fi gure out what’s been
done,” she said. “And most of
what I could fi nd was on sun-
stone as a gemstone.”
Jule Gilfi llan/Oregon Public Broadcasting
Oregon State University geologist Emily Cahoon holds an
Oregon sunstone at the Double Eagle Mine near Plush.