.GMF File Extension

Geological surface data set stored in the Geology Multi File (GMF) format, and used by various GIS programs; may contain x, y, z coordinates for a ground surface, as well as coordinates for one or more subsurface layers; may also include comments, the unit type (e.g., feet or meters), and labels for each surface data set.

Geology Multi-Files are used for recording collected geologic surface data and plotting 3D surface visualizations. GMF files are stored in an ASCII text format.