Petra,

Could the term you're looking for be "a volumetric, three-dimensional geologic model"? Or "Three-Dimensional Geologic Framework Modeling"? These terms are from a paper by USGS hydrologists Kyle Murray and Mark Hudson, titled "Three-Dimensional Geologic Framework Modeling". The word volumetric is often used for graphic displays such as you are describing.

Since I've been lurking for a good, long while, I'll introduce myself. I'm a retired Calif. Dept. of Forestry Fire Captain, with a long-standing interest in geology in general and seismology in particular. Just for kicks I'm back in school (Cuesta Community College), preparing to attend Cal Poly San Luis Obispo soon. I live in Arroyo Grande, just south of San Luis Obispo on California's central coast.