Lambda/Mu section on the left compared to a conventional reflectivity section on the right. In a stratigraphic section with low P-impedance contrast between shale and sand, or in a "hard sand" environment (such as this example), conventional reflectivity data often does not provide any DHI clues about the presence of hydrocarbons. On the converntional reflectivity section, sand tops are represented by a hard kick (red), bases by a soft kick (black). Where gas has been found in these reservoirs, the seismic section does not show any amplitude anomalis. The Lambda/Mu section, on the other hand, shows low Lambda/Mu anomalies in areas where gas has been found and produced. Low lambda indicates a formation with high compressibility (i.e. a gas-bearing reservoir). High Mu indicates a fomration with high rigidity (i.e. sandstone as opposed to shale).