c89a5c28_mical_Sediments_and_Landscapes__1
[0] Rock Coating Geography [2] This model has not yet explained the geography of rock coatings. [3] This model explains the geography of rock coatings (Dorn, 1998). [4] This model has not yet explained why rock varnish or silica glazes exists at one locale and not in other geographic settings. [1] 
The presence of rock varnish in a plethora of settings that lack repeated oxidation cycles challenges this model.
Rock Varnish Chapter 8 in Geochemical Sediments and Landscapes
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