Practicing “place” on rocks as we climbed up a mountain today.
On top! Watched a redtail hawk hunting the trees below us.
The cliffs here are at about the halfway mark of the Appalachian Trail, very near Harper’s Ferry. Picture taken with blue tooth and cellphone, as only Misto was with me today.
That sedimentary boulder above looks a lot like the erratics I find in NE Washington State. however mine are mostly granitic, and a few argillaceous. They are lithologies separate and distinct from the environment of their present location. Consequently, it is clear they were transported via some means -- force of water alone, floating encased within an iceberg, or direct glacial movement are the usual suspects. That boulder in the picture seems sedimentary, but those on top of the mountain appear to be granitic. Photos alone can be deceptive, but that is how they appear to me. So, I am guessing granite is the bedrock of the area. Patrick, what is your estimate of how that lone boulder was transported? The answer may be that it rolled or slid a short distance down from a similar outcropping on the hill/mountain, in which case it would not be termed an erratic, as it is the same kind of rock as the nearby outcropping. Rocks can really tell a story. Sometimes it is routine, and other times quite interesting, raising many new question. -- TEC
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