Instructions for Assessing Phase and Polarity
The key to the interpretive assessment of data phase and polarity is to identify high-amplitude reflections and to understand their geologic cause. Reflections are generated by acoustic-impedance contrasts, and thus high-amplitude reflections result from large contrasts. It is important to understand whether the reflection package studied is caused by a single interface or by a layer with interfaces top and base.
The probable cause of a package of high-amplitude reflections should be one of the following: