Shallow Thoughts : tags : trails

Akkana's Musings on Open Source, Science, and Nature.

Sat, 29 Nov 2008

Upheaval Dome: New research confirms impact theory

Kurt Fisher wrote to draw my attention to the latest Lunar Photo Of the Day (LPOD), a lovely shot he made of one of my favorite places anywhere, Upheaval Dome in Utah's Canyonlands National Park.

Upheaval Dome has long been strongly suspected to be a massive, eroded impact crater, but the LPOD highlights a study that finally puts this (non-)controversy to rest, Elmar Buchner and Thomas Kenkmann's Upheaval Dome, Utah, USA: Impact origin confirmed, documenting shocked quartz grains in the Kayenta sandstone of Upheaval's outer ring.

[Upheaval Dome] It's about time -- it's been pretty clear for many years that this structure was an impact formation, not a collapsed salt dome (the relative lack of salt in the core might have been a clue) but the park service doesn't seem to have gotten the message, giving equal weight to the salt-dome theory in all its Canyonlands literature and signs. Perhaps the Buchner and Kenkmann paper will finally convince them.

Reading about this gave me the push I needed to update my own Upheaval Dome page, adding links to the latest research and to the excellent Upheaval Dome Bibliography Kurt has put together. My page also badly needed a bigger view of the crater itself, so I stitched together a quick panorama of the view from the rim that I'd shot on a trip several years ago but never assembled.

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[ 12:15 Nov 29, 2008    More science/geology | permalink to this entry ]

Mon, 03 Jan 2005

New Year's Day in the Verdugos

Trails in the Verdugo hills above Burbank are a happy place, even when they're crowded on New Year's Day, with everyone taking advantage of a brief respite between two weeks of rainy weather. Everyone smiled, waved, or offered a cheery "Happy New Year!" It's nice to see people enjoying being out hiking, instead of grumping down the trail glowering at everyone, like some of the trails at home. Even after the sun disappeared and the wind came up, people seemed happy to be there. Mountain bikers, hikers, families, dog walkers, and one careful-stepping barefoot runner shared the trail without any conflict.

Up at the ridge, the crowds thinned out and we were alone. A large brown bird -- some sort of thrasher? -- belted out a song in a tree near the ridge saddle, and we watched a big red-tailed hawk slip silently out of a tree just below us and sail out across the canyon, adjusting her attitude entirely with the angle of her tail, scarcely moving her wings at all.

On the other side of a lookout peak, a towering brick chimney surrounded by pottery shards bears witness to past attempts to colonize this place. A kiln? And what was the purpose of the tall mast on the hill above it -- a flagpole? A lightning rod?

We lost ourselves following side trails down from the lightning rod, and found ourselves tracing deer trails through the chaparral. We examined rocks (is that layered black rock a coal seam, or pillow basalt to go with the nearby serpentine?) and eyed erosion gullies. We waved to bikers and got sniffed by dogs. A nice New Year's morning!

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[ 15:02 Jan 03, 2005    More nature/trails | permalink to this entry ]

Tue, 20 Jul 2004

Come, Lulu! Come!

It was hot again, so we drove to the coast and went for a hike in lower Purisima Creek. I wanted to try the Bald Knob trail, which neither of us had been on before. Bald Knob is about 2000', one of the highest points around, so as well as being "new steps", it promised a great view.

The bottom trail, by the creek, is in bloom, with lots of flowers I haven't seen anywhere else, as well as several types of almost-ripe berries, and interesting fruits that looked like small cherry tomatoes.

The trail begins to climb, and we climbed for several miles, out of the creek zone and into more typical oak and redwood forest. It wasn't as steep as I remembered it: fairly pleasant.

Then we rounded a corner, and suddenly the trail was full of dogs leaping at us! They were friendly, tail-wagging, just exhuberant. (Did I mention this preserve doesn't allow dogs?) Turns out the total was 7 dogs, only one on a leash, and one woman guiding them (and shouting at them to come back and shouting Sorry at us!)

I like dogs, and they like me, so it was no big deal, just the surprise of having that many dogs come out of nowhere in a place where I wasn't expecting to see any. The biggest one, a Rottweiler-looking dog, made me a bit nervous as he came bounding at me, until I established that he was indeed friendly. Dave wasn't as happy; he's had both good and bad experiences with dogs, and doesn't trust them.

The rest were a motley collection: a dalmatian, a shepherd-mix puppy, a dachshund, a bulldog, a small black longhair, and an old fat mixed-breed dog who waddled along bringing up the rear.

The woman came running up, apologizing to us and yelling at the dogs and threatening one of them (the Rottweiler?) that "You're going to go on the leash now!" The dogs reluctantly left off sniffing us, and the whole convention proceeded down the trail from which we'd come.

Well, not quite the whole convention. The dalmation lingered behind the others, then turned and purposefully trotted up the trail, passed us, and kept going. The woman and her six dogs were already a fair way down the trail, and the dalmation kept going the other way.

Well, eventually she discovered the dalmation was missing. You might think that someone walking one leashed and six unleashed dogs in a steep wooded open space preserve that doesn't allow dogs would keep a pretty sharp eye on them, and keep count. Maybe not. Anyway, we started hearing calls of "Lulu ... Lulu!"

I figured Lulu knew that she was being bad. If we could hear the calls, surely she could? Dave wondered, though, and tried shouting at her, and whistling. Lulu didn't give any sign. Perhaps she was actually hard of hearing.

Lulu explored the trail for a while, well ahead of us, then turned and ran down to explore a ravine. The woman and her pack was making good progress up the trail now, and when the came into sight we pointed out where Lulu had gone. Eventually the group was reunited, with a lot of "I can't believe you're doing this!" and "That's it, you're out of my group!"

All looked well, until the little black longhair decided she'd had enough, and lay down in the trail refusing to move. ("Missy! Missy, get up! We're leaving! We're going home!")

Dave and I continued up the trail, in order not to be any more distraction. The Bald Knob trail turned off just a few hundred feet beyond where Missy lay, anyway. As we walked up that trail, it looks like the group did get going again.

It was a strange encounter. I have mixed feelings about dog bans in parks: it's true that some dog owners aren't good about cleaning up after them, and it may even be true that they'd chase wildlife and cause problems that way (though most pet dogs aren't much at hunting, and no self-respecting wild squirrel or bird would be in much danger). I even have mixed feelings about leash laws, because I remember going for walks with my unleashed dogs, when I was growing up, and it was a lot more fun for them to be able to run and explore and not restrict themselves to my pace. Dog people don't have many places to go, any more, and it's getting tighter all the time.

On the other hand, such an obvious lack of control, in a public place where a lot of people might be afraid of dogs (even aside from the remote possibility that one might turn vicious), seems like a failure of judgement or worse. If I were a dog owner, I'd be pretty upset at someone like this possibly turning people more against dogs, and getting them banned in even more places.

We continued on our climb. The Bald Knob trail is lovely! It leaves the redwood forest and climbs through manzanita chapparal and into a woodland of moss-covered, gnarled, twisted shrubs. Occasionally you get tantalizing glimpses of a stunning view down to the ocean, or south toward the mountains north of Santa Cruz. Dave found a huge raven feather and presented me with it; I stuck it in my ponytail. Then I found one, and added it to the headdress, and he found a third and stuck it in. I'm sure I looked perfectly silly. But they were nice feathers. Finally, we got to the end of the trail, where it meets another trail ... and to the right, leading up to the top of the knob, was a gate saying "Private Property ahead. Do Not Enter." What a gyp! What an anticlimax! A map that clearly shows a high viewpoint, labelled by name and by elevation, inside the park boundary, but no trail actually goes to it! We waz robbed!

It was pretty disappointing. There really is no place you can see a large portion of the obviously stunning view. The trail was first rate, but their map is misleading and Bald Knob is not in fact a destination. On the way back we kept our eyes peeled for places we could wildcat through the brush, but it was always too thick, and we didn't try.

9.6 miles total, longer than our usual hike. Tired feet. But it was a nice day!

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[ 22:00 Jul 20, 2004    More nature/trails | permalink to this entry ]