A crack or cleft in a rock surface. This fissure can occur in joints between rock formations or in faults between tectonic plates.
"Sandstone fissures" by Damon Taylor is licensed under CC BY-NC-SA.
A01 The Blessing Way (01-07) p. 220
Merriam-Webster.com N.d. Fissure. http://www.merriam-webster.com/dictionary/fissure, accessed December 5, 2014.
Park, R. G. 1983 Foundations of Structural Geology. Glasgow, Blackie.
Tony Hillerman Portal