Saturday, September 17, 2016

Geo 893: A New Drain for Lost Lake

When I looked up from peering into Lost Lake's "drain hole" yesterday, Hollie and Gary had wandered over to another hole- this one still actively draining the edge of the lake. They had been up here the previous summer, and assured me it was new in the past year. Cool!

Many the the articles I've read since this spot hit public awareness have well over-stepped the edges of what we actually know about what's going on here. They've confidently claimed there's a lava tube here. The are tubes in the area, and that's certainly a possibility, but I saw nothing that I would say is good evidence of one here. The bottom of both holes are rubble-choked, and both are relatively shallow. Articles have claimed there are vast "underground rivers." This reflects a common misunderstanding about groundwater: most often (except in karst terrain) the water travels in pore spaces and fractures between the fragments that make up the rock or aggregate, rather than in one or more defined channels, which are intrinsic in the concept of "river."

To me, this type of reporting doesn't seem so much "sensationalist" as it does "poorly informed." I don't know that either is better or worse, but the latter seems more tolerable in my mind, since I can add corrections in posts like this. The former just exasperates me. The world we live in is an amazing and astonishing place. Reporters don't need to add fireworks, bells, and whistles to make it more so- in fact, that behavior distracts from the wonders in front of our faces.

Photo unmodified. September 7, 2016. ZoomEarth location. (Location approximate- can't resolve hole.)

Friday, September 16, 2016

Geo 892: Lost Lake's "Drain Hole"

The hole is both smaller and shallower than I expected, and at this time of year, well back from the water's edge. The lake bed appears to be composed of relatively thin laminae of ash and lapilli, and well lithified. This isn't surprising, given its location near the crest of the active section of the Cascades, but it isn't what I was expecting. Rubbly basalt and basaltic andesite dominate much of the central Oregon Cascades between our location here, along Highway 20, and McKenzie Pass along Rte. 242. However, my suspicion is that under these layers of tephra, the lava rubble is present; that would allow the water draining through this sinkhole to move to the water table, and, ultimately, re-emerge at Clear Lake.

Photo unmodified. September 7, 2016. ZoomEarth location. (Location approximate- can't resolve hole.)

Thursday, September 15, 2016

Geo 891: Lost Lake Basin and Hogg Rock

The basin the the foreground fills with water during late winter into spring, then slowly drains into the ground over the summer- there is no surface outlet. I've thought for years that Hogg Rock, in the back, looked like a tuya- a subglacial volcanic landform- in terms of its shape, and a couple months ago, I was informed by Adam Kent, a volcanologist at Oregon State, that it is.

Over the past year, there have been a number of stories in Oregon news sources about Lost Lake's "drain hole," starting with one in the Bend Bulletin. Even though I had never stopped here before, I was able to get a general sense of its location from the shape of the landscape in photos accompanying the articles. However Hollie and Gary had visited the site previously, so we didn't have to search it out. Nevertheless, my "general sense" turned out to be quite accurate. We're looking pretty much right at it, but from this angle, it's hidden in the grass and willows.

The countless dead trees on and around Hogg Rock were killed in a nasty fire a few years ago.

Photo unmodified. September 7, 2016. ZoomEarth location.

Wednesday, September 14, 2016

Geo 890: Saber-Toothed Nimravid and Trip Outline

Cast of saber-toothed Nimravid display along the Island in Time trail, John Day Fossil Beds National Monument, Sheep Rock Unit. Nothing for scale, but I think box is ~3 feet on the sides. In terms of representing the area, the above, to me, is perhaps the most iconic fossil photo of the trip
Interpretive sign associated with the fossil cast above. (Open pics in new tab for larger size and readability.)

I've got this written up, and I'm going to go ahead and post it, but I need to double check and clarify a few things in the outline below, so I may make some minor changes and expansions in coming days

Day 1 (Wednesday, Sept. 7): Travel to Dayville, Oregon, stops at
  1. Lost Lake to see "drain hole." There are *two* of them now.
  2. Gravel quarry on back side of Hogg Rock.
  3. Overlook viewing area, Prineville. (Whole trip was in OR.)
  4. Roadcut of Clarno Fm. near milepost 53 on Rte 126 (Folds, faults, leaves)
  5. Mascall, Picture Gorge Overlooks, 4 miles west of Dayville.
  6. "Home" for four nights: house rental in Dayville.
Day 2: Exploration of two of three John Day Fossil Beds National Monument Units, Sheep Rock and Painted Hills. Stops/hikes:
  1. Mascall Overlook to check out morning (vs. evening) light.
  2. Blue Basin, Island in Time trail. (Photos above)
  3. Foree, Story in Stone trail and Flood of Fire trail.
  4. Thomas Condon Paleontology Center. (Holy Cow! My head was swimming!)
  5. Visitor Center, Painted Hills Unit.
  6. Red Scar Knoll trail.
  7. Painted Cove trail.
  8. Lower Meyers Canyon- mostly to fritter away daylight until early evening at next stop. (Outside JD Fossil Beds NM.)
  9. Painted Hills Overlook Trail. (Wished we'd been there an hour later, but still awesome.)
Day 3: Return to Painted Hills Unit for morning light, then on to Clarno Unit, and Nut Beds in Fossil.
  1. Painted Hills Overlook for morning light. ( Not *quite* as spectacular as evening, but still...)
  2. Leaf Hill trail. (Meh)
  3. Caroll Rim Trail. (OMG overwhelmingly gorgeous! For n=1->infinity, repeat.)
  4. Drive to Clarno Unit, several roadside stops to puzzle out stratigraphy.
  5. Clarno Unit, Geologic Time trail and Trail of Fossils
  6. Fossil, OR High School, digging in famous Nut Beds- found some leaves.
  7. Return to Dayville through Sheep Rock Unit. Stopped to photograph Sheep Rock. (Lighting is poor midday.)
Day 4: Baker (ophiolite) and Izee (Crazy metamorphosed and folded seafloor sediments atop Baker) Terranes.
  1. Two stops in Baker Terrane on Rte. 395 just south of (City of) John Day.
  2. Five stops in Izee Terrane between mileposts 11 (I think- need to check) and 15 on Rte. 395.
  3. Return to John Day and explore ultramafics and associates of Baker Terrane from Forest Service roads (This had a number of stops, and is complicated. But a companion GPS'd 'em all, so I'll get better info.)
  4. Home.
Day 5: Return to Corvallis. Stops at:
  1. Smith Rocks State Park and a hike. I was too tired and sore to really enjoy this, misinterpreted a map, resulting in an extra mile or two of hiking, and lost my lens cap to the Crooked River. But better than I'm making it sound, plus I'd never been there before.
  2. Crooked River Gorge. A nice, easy amble, with a spectacular gorge 300 feet deep, and sheer basalt walls.
  3. Niagara County Park along N. Santiam River.
  4. Yay! Back in Corvallis.