Phreatic Tube

May 05, 2020

G1X_12670 Tulum Phreatic Tube in North Wall Boulder 1072x900

Photographer: Rick Scott 
Summary Author: Rick Scott 

The hole in this small limestone boulder is known as a phreatic tube. Phréar is a Greek word meaning well or spring. These tubes, this one is perhaps 2 inches (5 cm) in diameter, form beneath the water table typically in limestone terrain -- they act to drain water. Once in place, a cave may begin to take shape about such a tube as water erodes a passage through the limestone rock. Note that the boulders in this photo are part of the north wall around the Mayan ruins in Tulum, Mexico. Photo taken on March 11, 2020.

Photo Details: Camera: Canon PowerShot G1 X; Software: Adobe Photoshop CS6 (Macintosh); Exposure Time: 0.025s (1/40); Aperture: ƒ/8.0; ISO equivalent: 100; Focal Length: 28.3mm.