Wednesday, July 18, 2012
On the Road: Lassen Volcano National Park (July 18, 2012)
As a child, I remember being shown a large rock in Central Park (I lived in New York at the time--I was born in Manhattan) that was explained to me as a glacial anomaly--that is, a rock of very different composition or age from the surrounding rocks that had been brought along from somewhere far away, entrapped in ice, and then abandoned by the glacier that had shepherded it as the glacial ice melted away, a kind of orphan. I remember seeing other rocks in the park that showed signs of glacial scarring--linear grooves caused by small rocks embedded in ice being dragged over the surface of other rocks. Both left an impression on me (no pun intended). I'm always pleased to see examples of these two phenomena. I got to see both today in the park.