On Monday when I went to Powell’s grave, I noticed a few “boulder with a plaque” gravestones, the most distinctive of which was this lovely chunk of rose quartz: Quartz is a good choice, since it’s very very very stable at Earth surface conditions, and thus will stick around a lot longer than, say, a … Read more
Callan visits the grave of John Wesley Powell, second director of the USGS and explorer of the Grand Canyon, on an afternoon in Arlington National Cemetery.
While exploring the Rock Creek Cemetery last week, I noticed a couple of other interesting graves. This one, made of limestone, shows nice “reverse” cross-bedding: Here; I dialed up the contrast a bit to highlight these cool primary structures: It’s “reverse” because the tilting direction of the cross-beds switches from left (at the bottom) to … Read more
Callan pays a visit to the grave of celebrated paleontologist and geological administrator Charles D. Walcott.