The Friday fold is a slab of banded iron formation now dwelling in the University of Washington’s Department of Earth & Space Sciences. But where did it come from? India? Brazil? Perhaps you can help identify its provenance.
A final Friday fold from Madison, Wisconsin: this one a slab of cut and polished banded iron formation from Australia: What exquisitely beautiful rock! Happy Friday!
Banded iron formation is an “extinct rock” that can be found in ancient marine strata such as those found in the Barberton Greenstone Belt. Visit an outcrop on the Barberton GeoTrail and contemplate the bizarre anoxic world that Earth used to be.
Have a look at this week’s Friday fold – but be aware that it will be looking back!
Here are a few new images I’ve been working on with my home-based Magnify2 imaging system from GIGAmacro. Archean basement complex gneiss from the Gallatin Range of Montana: Link (If this looks familiar, that’s because one of the samples I imaged with the Photoscan 3D modeling technique and published on Sketchfab the week before last.) … Read more
The Friday fold is a trio of hand samples of folded banded iron formation from South Africa. Collected in 2012 as float from the “contorted bed” outcrop in downtown Johannesburg, these samples are only now being cut and polished in the lab at NOVA.
My NOVA colleague Shelley Jaye brought this gorgeous banded iron formation fold back from the Archean of Montana: Gorgeous to think about what this rock represents: (1) an anoxic atmosphere, a world where iron was able to dissolve in seawater; (2) some addition of oxygen, causing the iron to precipitate out as iron oxide minerals, … Read more
I was up in Carleton College (Northfield, Minnesota) for most of the week, working on a new teaching module for the InTeGrate project. On the way between our work area and the cafeteria where we ate lunch, we passed the geology department’s rock garden. They have some great specimens there, some big, some small. Here … Read more
The final meeting of my spring semester Snowball Earth class was a field trip to the University of Maryland, hosted by Snowball guru Jay Kaufman, a specialist in chemostratigraphy using stable isotopes. Here, Jay welcomes the class to his wet lab: Doing chemostratigraphy takes lots of samples. Here’s a drawer full of samples from one … Read more
Why are these people smiling? photo by Yvette Kuiper Because they are structural geologists, and they are psyched to be at an extraordinary outcrop: This is a famous pavement outcrop of polyphase-folded banded iron formation (BIF) near Soudan, Minnesota. I went there last fall before the annual meeting of the Geological Society of America, on … Read more
Norwegian structural geologist Haaken Fossen contributes two incredible images for this week’s Friday fold: a pavement of drastically-shortened banded iron formation from Minnesota, and a trio of three white granitoid dikes, buckled within a gneiss from the Jotun Nappe, in the Norwegian Caledonides. Gorgeous images of gorgeous folds, with links to the rest of Fossen’s collection.