This essay is an experiment in visual thinking that explores the process of geologic insight. The author asks the question: What differences make a difference when examining an outcrop? Marks on rocks gain meaning by being seen as something. Geologists, and those who can see and interpret marks as something are attuned to the sign language of the natural landscape. They understand, consciously or unconsciously, that the processes of testing and verification are dependent on the imaginative act of the creation of potential meanings. The simultaneous obscurity and super-abundance of data cannot be organized through basic uniformitarian principles alone, but are made coherent by an intelligent eye envisioning the outcrop.
