Underfoot along Summit

Question: what do we have lots of that's suitable for landscaping Prescott. Water is definitely not the answer. Which might explain all those rocky median strips next such streets as Summit where I took this handful of pictures recently. Quite fascinating, the variety.

This wildly patterned large stone sat in the midst of other, smaller chunks of similar schist.

While a lone quartz stone was a highlight amonst these darker rocks.

Sacred Heart sits well above street level; the slope landscaping uses sandstone in different sizes and shades of red.

Volcanics are popular, in part because of the color but also because, frankly, they are full of air bubbles and thus don't weigh nearly as much as other landscape rocks. You'll see a lot of "boulders" down in Sun City that are easy for an old-timer like me to heft; yes, they originated in certain types of volcanic explosions.

This is a more work-a-day gravel for parking spaces. Not nearly as bright or big as the other ground covering stones. Of course, all these spaces need to be carefully covered with black plastic tarps before dumping and arranging the rocks. Look what happens if you don't (below); Life has a way of finding every possible niche to make a home.

Now, if I may be permitted a bit of cynicism: I seriously doubt that folk (or institutions) are trying to save water when they landscape with stone. I'm sure they expect, instead, a carefree, permanent arrangement that is sufficiently unpleasant underfoot to discourage kids from rough housing or walked dogs from pooping. Almost the only maintenance needed is a blower to remove autumn's crop of leaves. Until. One day, a crack develops in that black tarp and Life reasserts itself. As pesky as it can be, I vote on the side of Life!

Road Trip 1: Cool Lava Flows

There's a temptation to compare digital point and shoot cameras to the old box Brownies. Yes, both were conceived as cameras for Everyman, and, indeed, both serve(d) that purpose well. One points; one shoots; one has a picture.

The resemblance stops there. Among the wonderful features of modern picture-taking technology is the shutter speed. It's high. Stops motion like you wouldn't believe. There's nothing like taking pictures out the windshield or the side window while a friend speeds down the highway!
Our return trip from Yarnell Tuesday gave me a chance to record those magnificent lava flows and mesas at the point halfway to the Sierra Prietas. SR89 swings a series of curves as it goes up and over the mesas. Just a short little segment of the road.

Aren't they beautiful? Again, I wonder where all the lava originated; that's a question I have often asked as I have wandered the area. There is, 10-15 miles to the south, Blowout Mountain. Might be the source; then again, might not. This isn't a section of Yavapai county that excites much study. The big geological money goes into potential copper mining sites or tracing water routes.

Very sere the day we drove through. Today there was an excellent rain, with more promised tomorrow. Perhaps we will see some greening yet before the heat crisps everything out.

A Look at Lava...

There's nothing like a road trip to learn a little local geology. Aside from 89A over Mingus Mountain, my favorite earth science lesson is the short climb out of the Verde Valley through the Copper Canyon pass on I-17. Besides, the cuts through the mountain are very pretty, if you like that sort of thing. I do. Returning from my Flagstaff weekend gave me an opportunity to see what kind of photography is possible from the co-pilot's seat in the little green car. It turns out that the shutter is fast enough to let me take pictures from a car moving at highway speeds!

Take a look at that mesa capped by a lava flow up ahead! That's the elevation we're headed for.

The wall to the right (above) has a thick layer of grey basalt on top of well baked soil which in turn looks like it is sitting on older lava.

The obvious lava here is underneath the baked soil. But there must have been lava atop that to cook the dirt!

This mountain slice appears to include at least three different basaltic episodes, including a flow that filled a major crevice in the older hillside, as outlined by the pink.

Stripes like these are particularly stunning in the late afternoon or early morning sun. Brings out the red in the one-time soil layer.

As our car nears the top of the pass, the grey basalt capping the mesas is very evident. Reminds one of gnomes and similar creatures.

The final road cut at the very top of the pass is missing the lava cap. Either it eroded away or perhaps it never existed!

These two pictures (above and below) are a reminder that the same sorts of road cuts exist within the Prescott city limits! The traffic light is just beyond the entrance to Costco on SR69, while the picture below immediately precedes the entrance to the WalMart coming from the East. By the way, for a really good look at the rock layers, pop into the WalMart parking lot. Gives you an idea of what Glassford Hill (our local volcano) was up to 14 million years ago.

The Glassford Hill basalts continue across SR89 south of the Dells and over past Willow Creek Road. If you take a good look at those huge 1.4 billion year old granites of the Dells, you will see that they disappear under the northwestern flank of our volcano.

If all this rock and geologic talk gets to you, Wide World of Maps down in the Valley has a geologic map of Yavapai County. If you go to their site, you might also look for a cool book -- Roadside Geology of Arizona. Or buy the book locally at The Worm or possibly Sharlot Hall Museum store. I also have in my library A Prescott Area Geologic Field Guide for Earth Science Week 1999 which I probably bought at a meeting of the local archeological society; no mention of it by The Google, so I can't recommend a source other than the library.