#Central Oregon

[gwbreeden]

Golden sunset over Mt Bachelor reflecting on Lake Aspen in Sunriver, Oregon.

#oregon #sunriver #mt bachelor #central oregon #sunset #sunsets

[bettergeology]

The Big Obsidian Flow is the youngest lava flow in Oregon, at the juvenescent age of ~1,300 years before present. It's a product of the most recent eruption of Newberry Volcano, the largest in the Cascade Range north of the California border (Medicine Lake Volcano is the largest overall). Newberry is a bit enigmatic - it's a huge volcano with a high rate of large eruptions but is not on the main Cascade volcanic arc. There's a number of converging fault zones in this area, which probably create significant crustal weakness allowing magma to percolate through the crust quickly.

Obsidian is common in lava flows of the rhyolitic composition, which is the most evolved kind of magma. Rhyolite magma spends lots of time spent in the crust for crustal rocks to contaminate the magma body and for heavier iron/magnesium-rich minerals to settle out, leaving behind a melt with over 68% silica (quartz). Silica is the same stuff regular glass is made of, so the higher your silica content then the glassier your lava flow is likely to be on the surface. The bands present in big chunks of obsidian are the result of shearing, differential cooling/composition, and flowing during the lava flow. This is very thick, sticky, viscous lava that doesn't like to flow. As it cools, it breaks rather than bends and turns the lava flow into a moonscape of glass shards and boulders.

The large amount of obsidian at this and other flows around Newberry Volcano is interesting because the volcano is mostly made of basalt - a lava with a near-opposite composition from rhyolite. Akin to Mauna Loa or Iceland, most of Newberry's lava flows form a broad shield more than 60 miles N-S and 30 miles E-W (roughly 100x50 km). The central part of the Volcano is about ten miles (16 km) across and contains a caldera formed when the central summit collapsed ~75,000 years ago. The caldera has been filled by subsequent eruptions and by two lakes separated by a big pumice cone. This means that the volcano produces - simultaneously - a wide range of magma compositions, indicating a complicated and long-lived magmatic system. Hazards from Newberry (to the 200,000 people living on its slopes) are not limited to fluid basalt eruptions that slowly blanket the landscape but also major explosive eruptions. The Big Obsidian Flow is a representative of the latter. Ash and debris from that eruption is found as far away as Idaho, and is many meters deep near the eruption's vent.

#oregon geology #geology #lava #magma #obsidian #volcano #volcanology #newberry volcano #central oregon #bendoregon #Cascade Volcanoes #PNW Volcano #rocks #oregon

[jtmportland]

eastern sky

#road trip #central oregon

[woodland--dweller]

Little photo dump from my latest Central Oregon Trip 🌲⛰️🔥

#central oregon #camping #camp #roadtrip #adventure #outdoors #toyota #toyota 4runner #4runner #mountain view #landscape #landscape photography #oregon #oregon explored #campfire #crackling fire #fire #forest #woods

[rafefar]

Mt Bachelor as seen from Forest Rd 45

#original photographer #photographers on tumblr #pacific wonderland #pacific northwest #rafefar #Oregon #central oregon #landscape photography #nature photography #iphone 8 plus

[antifainternational]

Just a week left to pick up January's Antifa Shirt of the Month, which comes courtesy of Central Oregon Anti-Fascist Action, with all proceeds going directly to support their work. Available in a range of colors & styles, including union-made apparel. Get yours here!

#antifa #central oregon #central oregon anti-fascist action #antifa shirt of the month #antifascist #antifascism

[automaticallyoutstanding]

Celestial bodies on display

#oregon #nature #pnw #central oregon #personal #photographers on tumblr #pacific northwest #night photography #landscape #mountains #astrophotography

[flyingiseasy-landingnotsomuch]

Smoky skies over Smith Rock State Park, Or.

I go to nature to be soothed and healed, and to have my senses put in order. –John Burroughs 

#personal #hike #pnw #central oregon

[floating-hasselblad]

Thinking about the central Oregon lava rock they took to the moon again

#its so special to me #my own little slice of home a quarter million miles away 😭😭😭 #apollo 15 #jim Irwin #central oregon #no matter where i am i can look up and always see a little piece of home

[summerwages]

Mount Washington..catching the eye on the way to pick sage..

#oregon #cascades #central oregon

[ordinary-gentleman-photograpy]

#mine #photography #wood #central oregon

[gwbreeden]

Canoes ready for a float down the Deschutes River in Sunriver, Oregon

#sunriver #central oregon #canoetrip #oregon #photographers on tumblr

[bettergeology]

Basalt columns in basalt of Newberry Volcano, lower Crooked River Gorge, central Oregon. Each one is 60-120 cm across (2-4 feet).

#oregon #geology #photography #pacific northwest #bettergeology #rocks #oregon geology #basalt #basalt columns #central oregon

[jtmportland]

#road trip #central oregon

[woodland--dweller]

These are the trips I live for 🌲⛰️💚🏹

#central oregon #tiktok #archery #compound bow #bow and arrow #camping #camp #adventure #tik tok #outdoors #forest #woods #country #country life #simple living #oregon #warren zeiders

[rafefar]

Central Oregon Cascades at sunset

#original photographer #photographers on tumblr #Central Oregon #cascades #rafefar #three sisters widerness #willamette national forest #pacific northwest #sunset #landscape photography