The key to transforming a geologic map into a database is having a data model that allows maximum flexibility for querying the data and also rigorously follows the facts implicit in the mapped relationships.  Building the architecture of a successful geological, map-related data base involves the basic understanding of geological relationships that go in to making a geologic map, the implied relationships that result from map patterns and some working knowledge of GIS engines, requirements and querying language.  In point of fact there is a remarkable similarity to the logic that goes into capturing the topology (see below) of a geologic map from the technical GIS standpoint, and the logic that goes into making a geology map to begin with.  In this regard, geologists usually have a strong intuitive sense of how a geologic map database is built; the processes of mapping and building a GIS are parallel ones.
 

GEOLOGIC DATA MODEL
This section outlines what we consider to be the most critical parts of a geologic data model and some of its implications and requirements for building, holding and interacting with the data in digital form. The model is not unique to the digital format or to two-dimensional representation although we limit ourselves to these here. This is not meant to be an exhaustive list of what can be done with such a dataset nor the advantages and disadvantages of using one, however, given the acknowledged advantages of computers for rapid map production and data manipulation, the advantages of a digital geologic database may be more readily apparent once this model has been examined.

Strongly suggested reading: Chapters 1-4, Bonham-Carter, G.F., 1994, Geographic Information Systems for Geoscientists, Pergamon, ISBN 0 08 042420 1. Most all of the examples in this book are from minerals exploration.
 

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