oregon geology

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Mt. Jefferson is Oregon’s second highest point, at 3,199 meters, it isn’t a giant, but the relatively low-lying mountains and plains around it ensure the volcano stands out. It is far more heavily glaciated than Mt. Hood, and creates a fantastic climbing challenge, as well as dramatic spires around its summit.To the original inhabitants, it is known as Seekseekqua. 

Here, the volcano (last erupted about 950 A.D.) is seen from the more iconic Oregon symbol of Mount Hood, above the Timberline Lodge (about 1,950 meters), and it is difficult to imagine the fire that brews below. After over 1,000 years of quiet, it is difficult to say how active the volcano is now, though it would be irresponsible to call it dead. Cascade volcanoes are on their long-term dying as their source of magma (the subjecting Juan de Fuca plate) plunges ever-deeper into the mantle. Eventually the crags shall be forever silent, and crumble away into eternity.


If you like these photos, please look at more from this trip over at my Flickr page.

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Sunrise over sea stacks, oregon coastline

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Geologic heroin at the Pallisades of John Day Fossil Beds Nat'l Monument, Clarno Unit, OR.

A volcanic complex to the south produced prodigious ash fall and tuffs. Over time these slid away in lahars or welded into ignimbrite. In this area this led to huge, well-stratified, windswept cliffs that include many fossils, mostly petrified wood and leaf impressions. This is the Pallisades Mudflow Member of the Clarno Formation (57-40 Ma or so)

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danleppold This is the basalt cobble beach at the Yaquina Head Lighthouse. Watch this with the volume turned up as the waves moving the basalt cobbles creates a really unique and pleasing sound. A great stop along the Oregon Coast.

Oregon’s Painted Hills are an area of great beauty; but it is a delicate place. The John Day Formation (Big Basin Member) forms stark badlands here; clay hills which are all that remain of soils from times long past. Red soils reflect a wet, tropical environment; while beige soils reflect a time of less precipitation, perhaps more akin to today’s coastal rainforest. Interestingly, the black streaks come from manganese; which was fixated in the soil much in the same way that phosphorous or nitrogen is nowadays.

The clay appears very resilient, standing against the dark hills, but a hard crust lines the hills. If you were to set foot on the hills, your foot would sink into soft silt, and create a crater on the stark hillside. They are fragile, and only you can help maintain their beauty by avoiding the urge to trudge out into the hills.

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Hovering over Sparks Lake, Oregon, at dusk

Red Hill. Clarno Unit, John Day Fossil Beds Nat’l Monument, OR.

This hill is made of ancient soils from the Clarno Formation, and are distinct from the ancient soils that make up the Painted Hills, which are part of the overlying John Day Formation. About 10 million years separate these hills with the more famous Painted Hills to the south, though their beauty is no less.

The bulk of the hillside is red, but contains bands of yellow on top and bottom, and pockets of blue and purple. Yellow soils were from temperate forests like those found on the Oregon coast today, and the red color come from tropical climates and forests. The purple and green deposits come from boggy environments, like swamps and river backwaters, and poke out from beneath a veneer of red washed down from above.

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Composite video of the MIlky Way over Mt. Baker, Oregon

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Ha, apparently the music for this morning shot of Mt. Hood is titled “Plate tectonics”