It’s Friday! Here’s a lovely sight, contributed by reader Fred Atwood: [youtube_agu id=Au-jIGfbs8g] Those are quartz veins in one of my favorite local rock units, the Mather Gorge Formation. Fred reports, This is at Madeira School in Great Falls between Black Pond and the Potomac. The rocks around Great Falls, particularly those on the Billy … Read more
Here’s a really cool hand sample my student Xiuming found when were were exploring the waste rock piles at the Golden Sunlight Mine near Whitehall, Montana, the week before last: That’s a vein of pyrite and chalcopyrite, offset along a series of three small fault zones: Pocket faults! Three for the price of one.
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
Callan reviews the geology of the superlatively auriferous Witwatersrand Supergroup of South Africa, and then zooms in on a distinctive marker bed near the base of the sequence. The deformation in this particular banded iron formation (BIF) is an aesthetic wonder, as this suite of images reveal. The layer outcrops in the heart of urban Johannesburg.