出典:Wikipedia
出典:『Wikipedia』 (2010/12/20 15:00 UTC 版)
Trimble Knob, located southwest of Monterey, VA, in Highland County, is a conical hill composed of basalt, a volcanic rock, of Eocene (early Tertiary) age. It is the eroded remnant of what was an active volcano or diatreme approximately 35 million years ago, making it one of the youngest volcanos on the east coast of North America.