Paleoproterozoic dikes in Archean granite, Laramie Range, Wyoming

At Morton Pass, where highway 34 crosses the crest of the Laramie Range, you can see a nice set of (younger) mafic dikes cutting (older) granite/gneiss basement complex. The pink stuff is Archean; the black stuff is Paleoproterozoic; around 2 billion years old. Click to enlarge I got to check out this outcrop on Tuesday … Read more

Friday fold: South Pass City, Wyoming

Two summers ago, my wife (then my very new wife) Lily and I participated in a two-week workshop for teachers on the energy resources of Wyoming. We also indulged in a visit to a mineral resource site: South Pass City, a site in the southern Wind River Uplift that was the second oldest incorporated town … Read more

Upturned Paleozoic strata on Highway 16, Bighorns, Wyoming

Here’s a terrific outcrop to start off the new year at Mountain Beltway. We’re back in the Bighorns of Wyoming here, on highway 16, traversing the southern portion of the range en route from Buffalo to South Pass City. Click to enlarge Annotated, expanded, and Easter-egg-embedded: Click to enlarge From a different perspective (uphill a … Read more

Vulture petroglyph from Castle Gardens, Wyoming

Happy new year! Time marches on – and here’s a reminder of times past… Check this out – a couple of what appear to be vultures, etched by native Americans into the siltstone at Castle Gardens, Wyoming: Diameter of the outer circle is probably 1.5 or 2 feet. My annotated (and generally embelished) version: I … Read more

Friday fold: Bighorn monocline

Happy Friday! The last one of 2012, in fact! To celebrate, check out this monocline on the western flank of the Bighorn Range in the Rockies of Wyoming: Click to enlarge Annotated. Check out those fine hogbacks! Previously, we also saw this same structure in this GigaPan: [gigapan id=”80440″] link

Stromatolites of the Green River Formation

The summer before last (2011), I spent some time in Wyoming on an energy resources field trip run by Sheridan College, and one stop we made was to look at “oil shale” (really kerogen-rich marlstone) of the Green River Formation, an Eocene lake deposit in southwestern Wyoming. The oil shale is exposed on the east … Read more