lol I'm not entirely sure I got the lensing part right since I am still trying to understand it I think the repetition of the waves at lower intensities would have more to do with it. (The lensing would just explain the layers of clay and other such 'water tight' materials above something that may have otherwise sorted higher.) Like aftershocks of an earth quake causing lower and lower tsunamis. What is distributed would vary in each level depending on the force of the waves and what soils were carried from other areas that the wave came from. Directions that could change as the waves traveled unblocked across the globe away from the epicenters, intersected or returned. It could even, I think plausibly, lay down sand eroded and carried from elsewhere over an already existing layer of shale, clay, etc that had sorted out in a previous liquification.