You are browsing the archive for June 2018 - Mountain Beltway.
25 June 2018
Mafic volcanics atop felsic instrusives: Sonora Pass, California
Sonora Pass, California, is a lovely place to examine a volcanic-on-plutonic nonconformity that spans about 80 million years of missing time. Let’s check it out on a photo-rich virtual field trip!
23 June 2018
Deformed conglomerate of Frog Lakes, California
Fifteen years after mapping deformed rocks of the Sierra Crest shear zone system in the high Sierra, a family vacation brings Callan back to the pre-batholith metasedimentary rocks which show a pronounced strain.
22 June 2018
Friday fold: Connemara Marble, Ireland
Another guest Friday fold (keep ’em coming, folks!) – This time from Eric Pyle of James Madison University: This is a weathered outcrop of the Connemara Marble in western Ireland, about a meter wide. Thanks for sharing, Eric!
15 June 2018
Friday fold: scenes from the Schilthorn cable-car
My friend Karen Aucker from NAGT’s Eastern Section shared these images (and a video!) of the folds she glimpsed from the cable-car on her way up the Schilthorn in Switzerland. I reckon they will do for our Friday fold: Thanks for sharing, Karen! These are great. Happy Friday, all!
9 June 2018
Friday fold: contorted carbonates of the Conestoga Formation
Today, in Millersville, Pennsylvania, on the campus on Millersville University, I saw these contorted carbonates. They are of the Cambrian Conestoga Formation, and I saw them on a NAGT Eastern Section field trip led by Lynn Marquez of Millersville University. This deformation is purported to be Taconian, but it looks very much like Alleghanian deformation in similar aged and composition rocks in Virginia. Interesting!
5 June 2018
Cross-bedding in Archean komatiitic ash deposits
Cross-bedding isn’t just for modern sedimentary deposits; you can find it in truly ancient ash deposits too! Let’s head to South Africa and take a look.
4 June 2018
Losing Ron and Declan
Last week, I lost two of my colleagues, Declan De Paor and Ron Schott. Both were involved in Google Earth for On-site & Distance Education (GEODE), the 5-year project I serve as PI on. Declan had battled various forms of cancer for many years, and most recently had developed several brain tumors. His passing was preceded by knowledge of his condition, while Ron’s death was unexpected and therefore shocking. Both …
1 June 2018
Friday fold: a quartet from Marli Miller’s website
Marli Miller is a senior instructor at the University of Oregon. She is the author of Roadside Geology of Oregon and (with Darrel Cowan) Roadside Geology of Washington. She’s also a very talented geological photographer. She launched a website recently to showcase her work and make it available for instructors: Geology Pics. After chatting with Marli a bit in Flagstaff at the Rocky Mountain / Cordilleran section meetings of GSA …