Geology of the Portland and Oregon Basin

The Portland Basin geology is an amazing story of floods of lava, rock, and ice. Retired attorney and educator Paul Edison-Lahm is Communications Director and Past-President of the Geological Society of the Oregon Country (GSOC) — the oldest collaboration of amateur and professional geologists in the Pacific Northwest. Paul has developed numerous Portland metro field trips with GSOC, which are the basis for this virtual presentation on the Portland Basin’s dramatic geological history.

[faylouise]

i am totally just a lover of geology without academic training, I absolutely loved this, thank you!

[vancouverguy]

Thanks for this. Been a hobby of mine for several years now and have done alot of reading and research on the Geology around Portland (since thats around where I live), but also around Washington, Oregon and the Southwest. Ive got a huge stack of papers of Geology about this area I've read over the years. Love presentations like this. Have a GSOC sticker on a car, from a Zettner presentation I saw at PSU by GSOC.

[porlando]

My exposure to geology in undergrad was wasted by my youth. This was absolutely fascinating!

[thomasauslander]

PSA "The Only Way to Fly!"

The amazing voice of Jim Backus.

[wesmahan]

Is the tip of Elk Rock Island (in the Willamette River just west of Milwaukie, OR) part of the old Siletzia? There is pillow basalt around the water's edge of Elk Rock Island.
(BTW, excellent presentation! It made me subscribe to this Youtube channel!)

[natafingerdude]

Very informative lecture, thanks for posting! The subduction animation @11:00 raises a question I've had for years and I'm sure there's an explanation even if it's just a lack of information on my part, but why aren't there massive amounts of debris stacked up along the continental shelves from millions of years of subduction? Especially, if subduction has enough force to push seafloor inland and raise mountains it seems impossible for there not to be an equally massive amount of surface evidence along the continents globally.

[dananorth]

The PNW has some of yhe most facinating geology on the planet. Of course if you look at the entire world IT'S ALL FACINATING! I suspect having grown up here I'm heavily biased though.

[PC-kddj]

My grandparents had a property on the quite flat countryside in Washington about 8 miles north of the I-205 Portland-Vancouver bridge on the Columbia River.

I remember seeing a 1-1/2 to 2 foot diameter granite boulder in the woods on their property. Is there a geologic explanation for this?

[JimMorgan-dn]

Makes me want to show you crazy looking geology I have seen in southeast Alaska, the geology here has turned me into a rock hound

[neilmackenzie]

Since this video was made there has been some rethinking about the Missoula floods. For example, there is evidence that some of the debris and erratics that lie in the channeled scablands of Eastern Washington came from the Canadian Okanogan valley far to the North.
Examination of sediment layers near the Wallula Gap seem to say the
Area was flooded dozens of times., and that the water sources may have been from under the Columbian Ice sheet.

[rooster]

How far will the content drop when the slip happens

[genekunkel]

we are thinking of moving to the Vancouver Washington area and looking for small acreage. When we start looking for land is there someone we can contact before we build regarding earthquakes.

[mrfxm]

Best thing a Rockhound can do is join a local gem and mineral club. 25 years member of the Arlington Gem and Mineral club in Texas trust me you won't be sorry.🇺🇲😎

[DeagleBeagle]

7:50 graben does NOT mean grave, grave is Grab in German but graben is named after the word ditch in English. Horst means an eagle's nest, both describe high and low points.

[susannell]

The tremor map shows a little activity for a long time. Is that normal?? Don't larger EQ happen during episodes of non activity there?The EQ of 1906 was large and they were large all around the globe. I looked it up. Expecting a BIG one??

[garyzick]

I never knew that a lava flow could go underneath subterranean sediments and then erupt as a volcano.

[playland]

Growing up in San Francisco was living on shaky ground.

[JMDinOKC]

Gotta be careful. There's pitfalls in them outcrops.

[GOWIN]

Eastern Portland is built on a Gold mine.

[PiedFifer]

26:16 Catastrophism with the expected anti-industrialism. The type of ideology that is destroying Portland much faster than geology.