Cleavage Refraction

Cleavage refraction refers to a change in orientation as cleavage passes from one lithology to another. Cleavage in the gray beds is dipping to the left and is closely spaced. Cleavage in the lower buff-colored beds is subvertical and more widely spaced. The lower beds are more competent. Photo credit: Art Goldstein. Image from website: http://www.science.ubc.ca/~eoswr/slidesets/keck/keck.html