I spent the day wandering around western Maryland with Dan Wagner, a soil geologist who is working with us on the C&O Canal project. I have learned most of what I know about soil by following Dan around while he works, and I very much enjoy these excursions. Today was a glorious spring day and we worked on some great sites, so it was best fun.
In these pictures Dan is using a bucket auger to bore a hole into the deep soils along the Potomac River. He removes the soil from the auger carefully and lays it out along the ground next to a tape measure, recreating the buried soil layers on the surface where he can examine them. This way he can spot buried topsoil layers that might hold archaeological sites and estimate their age. Or, he can determine that all of the soil in an area is recent to a depth beyond where we can reach with a shovel, so we don't waste time digging where nothing will be found.
One of Dan's holes hit rocks 1.5 feet down in a place where there shouldn't be any rock that close to the surface. We dug down with a shovel and discovered that we had hit a large prehistoric hearth, probably around a thousand years old. I know those rocks don't look like much, but they are broken in the way rocks are typically broken in hot fires. We will be back later to find out if this is just a small camp site or something much bigger.