On Saturday, I was due to take my Audubon class to the Billy Goat Trail. But, since we had so much rain earlier in the week, the Potomac was running higher than normal, and parts of the trail were flooded, so the Park Service closed it. I was ticked off that I couldn't take my students even on the non-flooded portions of the trail to show them pre-Taconian relict graded beds or Acadian lamprophyre dikes. But the NPS are sticklers for the rules, and there was one hyperenthusiastic volunteer standing guard to make sure we didn't venture onto the trail. So we didn't.

We walked another trail, the Berma Road, instead, which parallels the Washington Aqueduct from Great Falls down to the Old Anglers Inn. Along the way we saw plenty of metagraywacke, migmatite, and granite intrusions. Here's me pretending to 'hold up' up a massive metagraywacke xenolith in the Bear Island Granite:

We also saw a lot of structure, including boudinage, folds, and faults. While we didn't get to see some of the more striking features of the Billy Goat Trail proper, we made it work okay. And everybody in the class had a great sense of humor in regards to being kept off the BGT itself.

I thought this was a funny form of political protest:

Both photos by Audubon student Paula. Thanks, Paula!

Labels: granite, national parks, plutons, politics