Outside the Interzone
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This is Winter Falls, on the next drainage south from North Falls, so named due to the fact is more of a steady drip than a waterfall by mid summer. There are at least two Columbia River Basalt flows, with the boundary visible as the recess through the upper middle of this view of the cliff. About halfway up from that is another boundary, but I'm suspicious that's a textural change within a single flow- from hackley jointing to columnar jointing, for example, rather than a third lava flow. […]
Another pretty pool on the hike from North Falls to Winter Falls at Silver Falls State Park. I quite possibly wouldn't have posted this one, but Anne liked yesterday's shot and sent me a couple links to relevant papers (both PDFs) on pool and riffle morphology. I haven't had time to look them over carefully (Honestly, I've just read the abstracts thus far.), but the first discusses how large woody debris (notice the lack of such in today's and yesterday's photos, compared to the left side of […]
This is a typical stream morphology for mid-sized to small streams with a moderate to low gradient: relatively slow-moving pools separated by small "steps" of riffles. I've always assumed the riffles help keep dissolved oxygen levels close to a maximum, but during summer months, the main variable controlling that is water temperature, not aeration.Photo unmodified. August 30, 2012. FlashEarth Location (completely guessing on this one, but along correct drainage).
A week to two weeks ago, when I was discussing the large waterfall upstream from this spot, I emphasized the importance of the sedimentary beds between flows of Columbia River Basalt. Those beds weather and erode out faster than the basalt, undercutting it. This leaves suspended slabs of rock hanging, unsupported from below. From time to time, large blocks break off, which helps to maintain a vertical drop- that can be seen particularly well in this post. The same process works along the cliffs […]
This is a big-leaf maple down the creek a ways (maybe a mile or so?) below North Falls. Hardwoods like this don't add girth, generally speaking, as quickly as similar-aged conifers, so I'd guess this tree is in the neighborhood of a century old or so. When it was a mere sapling, it sent roots out in many directions to find water and the nutrients it needs. One of those became well established near what I'd presume was the then current soil level. In the past 100 years or so, soil has been […]
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