The bulbous stalactitic

Credit: UNM Newsroom
feature in the center of this photo is a phreatic overgrowth on speleothems (POS) that grew exactly at sea level and therefore represents an accurate relative sea level ~3.5 million years ago.
Credit: UNM Newsroom
feature in the center of this photo is a phreatic overgrowth on speleothems (POS) that grew exactly at sea level and therefore represents an accurate relative sea level ~3.5 million years ago.