We present phenomenology describing the internal structure of a turbulent zone, produced as the result of the push of a heavy fluid into a light one, for the case of immiscible fluids. One finds that the Kolmogorov cascade is realized within a range that grows with time, viz., scales between the mixing zone width, L∝t2 , and the viscous scale, η∝t-1/4 . Surface-tension effects lead to formation of an emulsionlike state. Density fluctuations on scales larger than the typical drop size, l , are governed by the Obukhov-Corrsin cascade. If l≫η , a wave energy cascade, related to capillary waves propagating along the surfaces of drops, is formed at scales below l , l∝t-2/5 .