colorado

The Liar’s Club, by Mary Karr

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I just finished this excellent memoir by Mary Karr, mostly about her childhood, mostly in east Texas. It’s not explicitly geological but it does feature an oil town economy and a hurricane, as well as some consideration of the Rocky Mountain Front Range in Colorado. I didn’t read it out of any illusions it would … Read more

Positively-weathering volcanic dike near Granby, Colorado

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My friend Barbara am Ende sent along this lovely image of a dike in Colorado: Here’s the site. You can see the dike in Google Earth. Dikes are fractures, filled with molten rock, which then cools and solidifies, sealing the crack shut. In this case, once it got uplifted to Earth’s surface and exposed, the … Read more

Friday fold: Ptygmatic Irving Fm., Colorado

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Another one from Kim: Kim says: Pygmatic folds in the Precambrian Irving Formation. I think this is 1.7 Ga deformation, late in the Yavapai orogeny, which added various arcs in Colorado to North America. Good place to think about strain ellipses in progressive deformation. Zooming in on the best part, and dialing up the contrast … Read more

Friday fold: Ouray Limestone, Colorado

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Kim Hannula shares a fold today: Kim says: The rocks folded here mostly the Devonian Ouray Limestone. There’s a fault through the outcrop, and another fault to the left of the photo. Regionally, the faults are mapped as normal faults, mostly with the east (right in photo) side down. Locally, that’s not what I see … Read more

Off to GSA

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This morning I’m on a flight to Denver, for the 125th anniversary annual meeting of the Geological Society of America. The annual GSA meeting is a special time of year for me, and for many geology professionals across the country. It’s an intense half-week of talks, sharing, learning, networking, hanging out with old friends, meeting … Read more

Macro GigaPans of Florissant insect fossils

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Today, for your viewing pleasure, please check out five macro GigaPans of insect fossils from the Florissant fossil beds in Colorado (34.07 +/-0.10Ma). These amazing specimens were collected by Joe Cancellare, a student working on research supervised by Josh Villalobos of El Paso Community College in El Paso, Texas. Our M.A.G.I.C. project is helping Joe … Read more

Roadside wonders of Route 287

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Northern Colorado’s route 287 connects Fort Collins, Colorado with Laramie, Wyoming. Along its length, it displays roadcuts into Archean-aged basement complex. Two of these outcrops are featured in this post: one metamorphic (mostly), and a second igneous (mostly), with some intriguing polka-dotted plutons.