This paper describes the development of applications for the interactive investigation of 3D geological and geophysical data, using an Interactive Workbench. The Interactive Workbench is essentially a large light table, on which stereo images are back-projected. The position of the user's head and hands are determined by a magnetic tracking system. The user interacts via a 3D mouse with geoscientific data objects that appear to be placed on or above the table. A high-end Silicon Graphics Workstation renders the stereo images 30 times a second for the users current eye position. We have implemented a pen-driven user interface as well as virtual tools for positioning, picking and cutting in order to visualize and, in some instances, edit geological objects like horizons, faults, seismic data, well bores, etc. This approach enables geoscientists to more fully exploit 3D geoscientific data by providing them with a truly 3D display that can be shared with others. In addition, the 3D interactivity that this technology provides can support more productive modeling of geoscientific data and more efficient verification of the resulting interpretations.© (2000) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.