c89a5c28_mical_Sediments_and_Landscapes__1
[0] Rock Varnish Variety and Geography [2] This model has not yet explained the variety and geography of rock varnish. [3] This model explains the variety and geography of rock varnish (chapter 10 in Dorn, 1998). [4] This model requires light and heat. Yet, both are known to be unnecessary for varnish formation (Anderson and Sollid, 1971; Dorn, 1998; Dorn and Dragovich, 1990; Dorn et al., 1992; Douglas, 1987; Douglas et al., 1994; Villa et al., 1995; Whalley et al., 1990). [1] 
This model has not yet explained the variety and geography of rock varnish.
Rock Varnish Chapter 8 in Geochemical Sediments and Landscapes
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