Computer information systems that will archive, query, retrieve, and display geologic information tailored to specific requirements are the foundation for a leap in scientific development similar to that fostered by the invention of the geologic map. In order to achieve this potential, some standardization of the conceptual model for basic elements of geoscience is required to provide a consistent framework for developing interoperable systems. Models for three concepts that are central to geologic science, Earth material, geologic units, and geologic structure, are proposed as a starting point for this framework. An Earth material is a substance defined by chemical constituents,...