We drove to Carmel Church Sunday night, with the intention of starting work this morning. I hadn’t counted on waking up this morning to the area’s first significant snowfall this winter! Heavy snow continued until around 1:30, and by 4:30 I decided to at least go into the quarry to see how the outcrop had stood up to the winter.
Our first task was to clear the trees that had fallen across the entrance road. This is a common-enough occurrence that I always bring a chainsaw. The trees actually weren’t too bad this year, and we were able to clear them quickly.
The site itself is in good shape, except for the covering of snow. It’s not as muddy as I had anticipated, although it could be worse tomorrow when more of the snow has melted.
One new feature that initially confused me was this flooded hole in the Nanjemoy Formation, in the floor of one of our old excavation pits:
This was almost a meter deep at its deepest point. We don’t leave holes like this behind for just this reason; we don’t want pools of standing water around the outcrop that could seep into the bonebed and damage bones, or that can serve as mosquito breeding grounds in the summer. But I think I figured out how the hole formed. Stepping back, you can see that the hole sits at the base of a vertical wall (made during excavating), and that a major runoff channel comes down the hill at that point:
After a rain, runoff water always comes down the hill into the excavation area as a miniature 2-meter waterfall. Usually it hits the Calvert Formation, which is clay-rich and relatively impermeable, and then continues further down the hill. But this is one of our old excavation pits, so the Calvert has been completely removed here. Instead, the water is hitting the underlying Nanjemoy Formation, which is much sandier and softer than the Calvert. I think that the runoff waterfall has drilled a hole into the Nanjemoy. Before we leave, we’ll modify the pit so that it drains better.
Tomorrow morning we plan to go back in and see if the snow has melted enough to start digging.