Saturday, December 29, 2018

What a Trip! 2018 Edition (Part One)

I did two geology trips in 2018. The first was with a couple of non-geology friends, in mid-June, up to Quartzville. They had a great time, but I kinda feel as if I've beaten Quartzville to death, and I didn't take any photos (though I did, of course, come home with more rocks), so rather than belaboring it beyond saying we basically followed this guide, that's all I have to say about that.

On the second trip, from September 4 through 9, we hightailed across the Cascades at Willamette Pass (Route 58, from roughly Eugene to Crescent), and made a quick stop at Salt Creek Falls. That waterfall is the second tallest in Oregon, after Multnomah Falls.
I also pointed out the glacial striations on the columnar basalt near the top of the falls.
These two photos weren't from this trip, but from August 8, 2011. The memory chip in my camera was nervously close to full, and the card reader in my laptop stopped working, so I had no way to make more space on it (as far as I knew at the time). As a result, I was more miserly about photos than I might normally have been.

Our first real excursion, after coming down the east side, taking the Crescent Cutoff from Rte 58 to Crescent, then north on Rte 97 to La Pine, then southeast on Rte 31 to Fort Rock Road, and east to Christmas Valley, was at Crack in the Ground. Location here, cross hairs over the parking area.
As you can see in this shot, there's a decent path, with a lot of ups and downs over piles of breakdown. Here, I'm at the top of a "hill." looking down into a "valley" with Hollie and Gary. Crack in the Ground is a weird feature, and unique as far as I know. When I was an undergrad, it was thought that asymmetric subsidence associated with the emptying of the magma chamber that fed the Four Cones Volcanic Field had localized flexure at this location, essentially "hinging" along this line, with the east side down, and the west side remaining at its former elevation. Evidence has popped up (I don't have the source available at this moment) that there is a pre-existing fault under the younger lava flows, so that fault may have provided a weak area that helped localize the flexure more narrowly to this location. The total length of the walk, from the car to the crack, through the most popular segment, and back to the car again, is probably about a mile and a half. The crack totals about six miles long, but much of it is prohibitively rugged for me, with enormous piles of large boulders tumbled one atop the other. This segment, though it has a lot of up-and-down clambering, is pretty easy.
The crack has its own microclimate, cooler and moister than the surrounding arid scrub. I was quite started the first time I encountered stinging nettle there (and a little bit itchy and sore), but I've learned to expect and point it out to others. Also, being cooler, and largely shaded, it can hold winter snow quite a way into summer. There are stories of pre-refrigeration locals coming out here to have ice cream parties into July- a month that would make ice cream an especially welcome treat for a sweltering summer.
Looking up to a juniper on the rim.
And back out again! Looking north from the south end of the easy segment of the crack.
We walked back to the car along the west side of the crack. Looking northeast, you can see that this surface is higher than the ground over there. What you *can't* see is that there's a ~60 foot drop just past that line of sage in the foreground.

From Crack in the Ground, we drove back to Christmas Valley, then followed the Christmas Valley Highway east to Rte 395, where we turned south. Just before that road descends toward Abert Rim, there's a well-maintained gravel road, "The Hogback," that trends southeast into the Warner Valley and the foot of Hart Mountain. As we approached the tiny little town of Plush, we turned north to the BLM Sunstone area, where we spent the night, awed by the utterly perfect skies for star watching.

I've just decided to do this as a series. Given the progress today, I'm doubtful I'm going to get the whole trip written up before Interzone closes on New Year's Eve. Better to publish in dribs and drabs than to having almost nothing for 2018. It'll get finished when it gets finished, but having it incomplete will perhaps motivate me to get it done a bit sooner.