Friday fold: Archean gneiss from Montana

Fine faulting

Check it out: In the canyon of the Jefferson River, Montana, you can find yourself some limestone (Mississippian Madison Group, I think of the Lodgepole Formation) that has seen a wee bit of faulting: And here’s an annotated copy… Both of these images are enlargeable by clicking through (twice): Note the quarter for scale: this [...]

Friday fold: tight syncline in Montana

This fold is located on Highway 287, north of Wolf Creek, Montana. Annotated version: As with last week’s Friday Fold, this fold owes its existence to (a) deposition of sandstone and shale in the Western Interior Seaway, and (b) deformation under a giant thrust sheet during the thin-skinned compressional tectonics of the  Sevier Orogeny. In [...]

Friday fold: Cretaceous sandstone

Happy Friday, everyone!

Jointed Virgelle

One of the stops my Rockies students and I made this summer was a dinosaur paleontology tour through the Two Medicine Dinosaur Center in Bynum, Montana. The folks there are very accommodating, and at my request gave the class a bit of stratigraphic context for the dinosaur fossils. For instance, we visited the geologic formation [...]

Rocks of Glacier National Park

This is the second of my Rockies course student projects that I wanted to share here on the blog: it is a guest post by Filip Goc. Enjoy! -CB —————————————————————————– The Rocks around Glacier National Park, Montana: Introduction to the formations The geology around Glacier National Park is great for beginners because the area is [...]

Volcanic features of the Rockies trip

This weekend, I wanted to share some of the best work from this year’s Rockies field course students. Let’s start with a nice video by Marcelo Arispe: I thought this was a really nice job making a video using still images and a voiceover. The only thing I would change would be in the Gallatin [...]

In which I am eaten by a stromatolitic Pac-Man

Let this be a lesson to you, kids. Don’t get too close to wild stromatolites, even if they are Mesoproterozoic… These exceptionally large stromatolites are on the threshold of the Grinnell Glacier, in Glacier National Park, Montana. No stromatolites or geologists were harmed during the production of this blog post. Photos by NOVA Rockies student [...]

The routine

It’s that time of year for me… summer’s here, and I’m winding up my duties at NOVA in preparation for some travels. We leave Sunday night for two weeks in Turkey, followed by my regional field geology course in Montana (also two weeks), followed by some family time and mountain climbing in New Hampshire (three [...]

The LaHood Conglomerate

The Belt Supergroup is a series of sedimentary strata laid down in the Belt Sea, an inland sea (like modern Hudson Bay) that existed in the northwestern (by present coordinates) part of ancestral North America during the Mesoproterozoic era of geologic time. Estimates of the absolute age of these rocks range from 1470 to 1400 [...]