step 108 the generic type of the resulting surface slice is determined by the manner in which the variant is represented for instance if the variant is represented by its position in time the resulting surface slice is a time surface slice with a single time contour in fig3 a time contour 46 represents a single time contour should a user want more information than that which is provided in a single time sample two methods of achieving this are available the methods differ in how the information from adjacent time samples is placed onto a single surface slice the first method involves using this embodiment of the invention to generate a plurality of successively adjacent surface slices from a plurality of similarly configured arbitrary surfaces that are separated by one data sample once these surface slices have been generated several adjacent surface slices are combined into a single 34 thick 34 surface slice the thickness of the new surface slice is proportional to the number of original surface slices combined into it the adjacent arbitrary surfaces can be defined in several different ways there are two ways that are particularly useful the first is to define arbitrary surfaces that are separated by one data sample as measured parallel to one of the data dimensions the vertical data dimension generally proves most useful the second manner is to define arbitrary surfaces that are separated by one unit distance as measured perpendicular to the arbitrary surface fig8 shows a three dimensional data set with a dipping horizon 220 located within the volume typically in the case of seismic data with the original arbitrary surface being a.