In fresh water lakes, the deep water sediments are usually fine silts and clays mixed with some organic debris of plant and animal life which inhabited the overlying waters. The larger clastic material is concentrated near the areas of inflow except in the very large lakes where sand, gravel, and pebbles are moved by longshore drift. In larger lakes, the clay deposits away from the source are very uniform.
In saline lakes, clay deposition is also prevalent. Because most saline lakes are relatively shallow, the lateral mixing of sediment is restricted, and thus most of the coarser material is deposited near the alluvial or deltaic fans. Staying in suspension, the clays become widespread in the lake.