Abstract: A method for modeling a geological domain in a computer system, in which the computer system includes data processing and data storage modules, one or more user input devices and a display device, in which the system first receives data relating to faults within the domain. Then there is created a surface plot for each fault described in the data, each surface plot being extended to divide the domain in two portions, and the surface plots are combined into a fault network containing all faults described in the data and displayed on the display apparatus. The network display is modified in response to user input, including the first step of rotating the display about its horizontal and vertical axes as desired to inspect the same. Then the system receives manual truncation commands and truncates indicated fault portions responsive to the same.