More xenoliths from the Boulder Batholith

The week before last, I showed you the Boulder Batholith, as it crops out southeast of Butte, Montana. Today, I’ll share a few more photos of xenoliths (or perhaps microgranular mafic enclaves?) from that same outcrop: Man, I miss that old Swiss Army knife. The damned security actors at Calgary Airport confiscated it last summer. … Read more

Stratigraphy session

What are these students up to? I’ll give you a hint: this is Dinosaur Provincial Park in the Great Plains of southern Alberta. The badlands style topography here offers a nice vertical section through clastic sedimentary rocks originally deposited adjacent to the Western Interior Seaway. On our Canadian Rockies field course in July, my co-instructor … Read more

Contact of the Campus Andesite with host rocks

First thing we saw on the post-InTeGrate field trip to the rocks of El Paso, Texas, was this contact between the aforementioned Campus Andesite, and the Cretaceous sedimentary rocks into which it intruded (contact metamorphosed in the area of this photo): I decided to try switching up my annotation fonts. Whaddya think?