The conventional application of seismic data to mapping depth and attitude of reflecting interfaces has been supplemented in recent years by measurements of velocity and amplitude for stratigraphic and lithologic information. Data patterns and angular relations between events provide clues to lithology and geologic history. Such data can be interpreted in terms of silica-clastic/carbonate/evaporite lithology, competent or plastic rocks, rigid or compactible sediments, depositional processes and environment, direction of sediment source, periods of subsidence/growth/erosion, etc. Special attention is given to (1) resolution of events, (2) the measurement and interpretation of seismic velocity, (3) amplitude measurements, and (4) display, so as to help an interpreter grasp he interrelations of data elements. The interpreter must bring together imagination and geologic and geophysical knowledge to discover possibilities while avoiding pitfalls of untenable geologic conclusions or of misinterpretation of seismic data.