Chatter mark explained

In glacial geology, a chatter mark is a wedge-shaped mark (usually of a series of such marks) left by chipping of a bedrock surface by rock fragments carried in the base of a glacier (glacial plucking). Marks tend to be crescent-shaped and oriented at right angles to the direction of ice movement.[1] [2]

There are three different types of chatter marks. The crescentic gouge is an upstream concave that is made by the removal of a piece of rock. The crescentic fracture is a downstream concave that is also made by the removal of rock. The lunate fracture is also a downstream concave made without the removal of rock.[3]

See also

Notes and References

  1. Marshak, Stephen, 2009, Essentials of Geology, W. W. Norton & Company, 3rd ed.
  2. Dictionary of Geological Terms, Third Edition (1984). American Geological Institute Publications. Robert L. Bates and Julia A. Jackson, Editors
  3. http://www.britannica.com/EBchecked/topic/107979/chatter-mark Encyclopædia Britannica