The Geology sub-model provides for naming, defining and characterizing geologic features. It does not include the representation of the occurrences of the feature. It is not about the locating of the feature in space. For example the geology model allows you to store and share Formation names and use them to pick well markers while making geologic interpretations. The contour maps derived from these picks are an example of the geometric represent the geologic feature. Also the Geology sub-model allows you to assemble geologic features from it�s parts, create synonyms, and build hierarchies of features. In short, the geology model is about names and definitions of geologic features used to tag data. The most common application is to create a shared list of project stratigraphic names.