Ron Schott’s Geology Home Companion Blog

We have yet another first time winner who doesn’t have his own blog, so I’m going to host once more, but hopefully this will be my last hosting gig for a while. Rod finally solved Dean’s needle-in-a-haystack patterned ground stumper about a week ago, but I’ve been slow to post his follow up. Since I’m headed out of town for a couple of weeks I may not respond immediately to solutions for this one. If one of the veterans solves it, you’ll know how to post the next one on your own geoblog.

For any novices, the object of WoGE is to identify the latitude and longitude of the image below and explain the geological origins of the area pictured. The first person to successfully solve both has the honor of hosting the next WoGE on their own geoblog. Don’t have your own geoblog yet? Start one today!

Rod wanted to stick with a mantle plume theme but he’s chosen a little bit wider field of view “sort of in [his] backyard”. Rod gave me a nice description of the geology seen here so I won’t be playing myself.

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Apologies for the delay in getting this one posted. It’s been a busy couple of weeks as the semester wound down.

Good Luck!

At the end of my last post chronicling my return from AGU, I had just departed Organ Pipe National Monument and the Ajo, Arizona area. Having holed up in Organ Pipe for two nights waiting for a Pacific storm system to pass me by I was eager to put some miles in the rear view mirror. So eager, as it turned out, that I just about ran up on the back end of the storm again the following afternoon as I arrived in the Bisbee, Arizona area. The three GigaPans I shot on December 27th were not much fun to shoot, as I was fighting clouds and near freezing temperatures and winds in mid-afternoon. Nonetheless, the GigaPan of downtown Bisbee turned out to be a monster, from an excellent vantage point, and as a result there’s a ton of great detail to explore.

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The other two GigaPans I shot that day were both roadcuts. Neither is remarkable as a standalone GigaPan, but each illustrates some interesting geology. The first was shot on the way into Bisbee, just north of town on State Highway 80. It illustrates an nonconformity between the schistose bedrock of the Bisbee Range and the overlying Quaternary fanglomerates, rich with granitic clasts
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The final GigaPan of the day was shot adjacent to the Lavender Pit copper mine. Unfortunately the lighting of the open-pit itself was not optimal for viewing from the public highway during the late afternoon, so I opted to shoot the roadcut opposite the pit across the highway. You can see the effects of hydrothermal alteration of the rocks in the remarkably orange hillsides above the pit. There isn’t a whole lot of interesting detail that I’ve yet discovered beyond the alteration colors, but maybe a geologist with a sharper eye than mine can spot some interesting structural or mineralogical details.

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Departing Bisbee, I took dinner in Douglas, AZ and then headed north, planning to camp in Chiracahua National Monument for the night. Arriving there well after dark I was greeted by bone chilling temperatures and I decided that discretion was the better part of valor, so I beat a hasty retreat to a warm motel in Willcox, AZ on Interstate 10. Probably a good idea, because it gave me a chance to upload lots of photos and check the weather. Realizing that I had, perhaps, been too hasty in bypassing the Tucson area, and in light of a favorable weather forecast for the upcoming week, the decision to double back to Tucson and the Saguaro National Park became one that in hindsight I certainly don’t regret.

A great Easter gift from Google Earth! Base imagery in many states (Kansas among them) is updated from the old 15m resolution to new 1m(?) resolution.

For an example of how improved this is see the Castle Rock area of Gove County, Kansas before (left) and after (right) at approximately the same scale…

Zooming in a little closer you can make out Castle Rock itself and much more of the detail of the badlands area just south of it, as well.

I wonder if the base elevation model has been updated, too, or whether I’m just noticing the elevation more now that I can see the sharper imagery on top of it?

Dean Garwood (another first time winner!) solved Paul Arndts’ Montana mystery locale and correctly identified it as a favorite geology field camp mapping locality as well. Since Dean has no blog, I’m going to post his WoGE #166. Can we string three brand new WoGE winners together? Somehow I doubt it, but I’d love to be proven wrong. As all of the veterans know, you can claim your spot in the halls of WoGE honor by identifying the location of the Google Earth screen capture below (latitude and longitude will do nicely) and explaining the geologic significance of the landforms visible in the image. Still no Schott Rule (I won’t be participating since I already know the location), so let’s see if the veterans are on their toes.

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Good Luck!

Now that residents of the Cook Inlet region of Alaska (including Anchorage) are dealing with volcanic ash falls from Redoubt, I’ve read a bunch of tweets warning folks not to use their windshield wipers to push dry ash off their cars windshields as it may scratch the windshield. Indeed, this recommendation is found among the recommendations in the USGS Ashfall Preparedness website.

And yet, something initially struck me as odd about this recommendation. Volcanic ash is primarily composed of tiny glassy shards of quenched magma, or obsidian. Obsidian, like windshield glass, has a Mohs hardness of 5-5.5. Normally, objects with the same or very similar hardness will not noticably scratch each other. No doubt, the jagged ash fragments are likely to tear up the rubber windshield wipers, but not the windshield itself. At least, that was how I thought about it at first.

Of course, I was overlooking the fact that most erupting magmas are not aphyric (crystal free). And a bunch of new SEM photos of minerals in the Redoubt ash now makes that clear to me. It is these minerals, with Mohs hardnesses in the 6-7 range, that will actually abrade your windshield if you aren’t careful.

Among the minerals identified in the SEM photos are amphibole (with reaction rims and nice cleavage), plagioclase (showing concentric compositional zoning and a sieve-textured core), orthopyroxene, calcic pyroxene (augite?), and oxide microlites. I haven’t yet read or heard of any completed chemical analyses of the ash, but this mineralogy is consistent with the andesite-dacite composition of magmas erupted in 1989-1990. As much as I’ve enjoyed following the webicorders and webcams as the eruption was ramping up, it’s good to finally see some petrologic/petrographic data.

Paul Arndts (aka Felsic Intruder) correctly identified the Kinmei Seamount at the bend of the Hawaiian-Emperor Seamount chain. Since Paul has no blog, I’m going to post his WoGE #165. To earn the honor and glory that accompanies all WoGE solutions you merely need to identify the location of the Google Earth screen capture below (latitude and longitude will do nicely) and explain the geologic significance of the landforms visible in the image. There’s no Schott Rule this time, but I won’t be participating since I already know the location.

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Good Luck!

You may recall that on my return trip from AGU last December weather patterns had forced me to change plans in order to keep GigaPanning. Well, after the Calico Hills I proceeded south through the Mojave with a brief stops at Pisgah and Amboy Craters and Dish Hill. I can’t show you the GigaPan I shot at the Pisgah Lava Field, unfortunately because the GigaPan Stitching software has a lingering bug that prevents me from stitching my big 360 degree panoramas. By the time I got to Dish Hill the sun was already setting, so I didn’t even have much time to look for xenoliths. (For all you WoGE fans, be sure to note that Peter Luffi has a new article out in JGR that has some very interesting insights into the nature of the lithospheric mantle based on studies of these xenoliths.)

After a night in Blythe, CA and a flat tire near Gila Bend, AZ on Christmas Eve, I finally got about as far south as I could go and camped two nights in Organ Pipe Cactus National Monument. Christmas Day was pretty grey and chilly so I spent most of the day reading in my car. Finally, on Boxing Day the weather began breaking and I was able to get out and shoot some GigaPans again.

The first one is taken on the loop drive in Organ Pipe Cactus NM. The rocks are Tertiary volcanics and the sky was still pretty grey. But look at all the pretty cacti!

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Noticing that the high deck of clouds was clearing from the north, I decided to go back up to Ajo, Arizona to see if I could GigaPan the open pit copper mine there. Unfortunately the only public viewpoint of the pit was looking south into the sun, and the view wasn’t great anyhow. Unable to GigaPan the pit, I decided to do the next best thing by GigaPanning the piles of colorful overburden (technically not the tailings) that were removed to create the pit.

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In searching for a spot to get an overview of the open pit, I had passed a couple of places that had a decent vantage point of the town of Ajo. Since the light wasn’t right for a shot in the downtown plaza, I decided to go for an overview of the town instead. It turns out that there was a lot of good detail to see, making this one of my more popular GigaPans for exploring and bookmarking.

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Finally, late in the day, I decided to make one more brief foray down to Organ Pipe NM to catch the setting sun illuminating the west face of the Ajo Range. More Tertiary volcanics dominate this view, thought I believe there are some Paleozoic & Mesozoic sedimentary rocks somewhere in the neighborhood.

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The Organ Pipe area is a lovely corner of Arizona with some wonderful Basin and Range geology. Although it wasn’t on my original itinerary, I’m glad to have had the chance to get back this way, almost two decades since my first visit (on a Colgate University January Term geology trip). Hopefully it won’t take me another two decades to get back again.

I discovered Peter’s devilish Dagestani deformation, so it’s my turn again to see if I can stump the Geoblogosphere. Actually, I’m picking a big fat wet one for all of you. Shouldn’t be too hard to find since it covers a huge area, but the real challenge (after you’ve identified its latitude and longitude) will be in identifying the geologic significance of this spot.

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Once again, I’ll forgo the Schott Rule, but I’d ask recent winners to give the newbies maybe a day or so. (Post time: 23:58 CDT). Good luck!

There’s been an overwhelming and uniformly positive response to the Google Earth Geology Layer post I made a week ago. I’m still trying to digest all of the feedback, but as soon as I have a chance to I’ll do a follow up. Meanwhile, back to my regularly scheduled blogging…

The Calico Folds, just northeast of Barstow, California was the next geological stop on my journey back to Hays from AGU last December. The GigaPan below is one of four I shot at this locality. You can explore the whole set in their “natural habitat” in Google Earth. This one’s for all of the structural geologists out there.

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Remarkably little is written up about this locality in guidebooks of the region, despite the fact that these spectacular folds are featured in a number of textbooks. Remarkably, though I’ve passed through this region at least twice in my geological career I was unaware of the location of these spectacular folds until I did a little sleuthing on Flickr this past year. This leads me to believe that they are a “secret” location visited by many classes and field camps, though I have no direct knowledge of that. If anyone knows of any guidebook descriptions of this locality that may have escaped my attention or of any classes that visit this locality for fieldwork I’d be interested to know about them.

It’s remarkable to me that such a spectacular and generally accessible locality could be such a well kept secret – well, no more!

PodClast #7 is available for your listening pleasure over at goodSchist. Lots of juicy discussion of Precambrian sponges, the proposed Google Earth geology layer, and more! Hope you have as much fun listening to it as we had creating it!