Seismic geohistory analysis is a method of reconstructing an interpreted seismic section, assuming generalized porosity-traveltime and depth-traveltime relations. The method can indicate timing of fault movements, juxtaposition of units across faults in the past, and depth or traveltime to specific reflection horizons throughout geologic time. The method applied to the Lennard Shelf of the Canning Basin shows that the major movements of the Pinnacle fault system occurred during the Ordovician and Middle Carboniferous. The movements reflect subsidence of the Fitzroy Trough, which is basinward of the Lennard Shelf. The analysis shows a prograding sediment wedge on the margin of the Lennard Shelf to have had temperatures in the range 110 degrees -116 degrees C sine Permian times. Being within the thermal oil window for the past 280 Ma, the sediment wedge may be good hydrocarbon prospect.--Modified journal abstract.