The diagrams illustrate how sedimentary rock is created in coastal areas. Overall, sandstone is come from mountainside. After physical and chemical changes, they become accomplished rock under the water.
Initially, the rainfall makes the soil on the mountain side start to fissure. Thanks to the expansion of cracks associated with the breaking of rock by frozen rainwater, it helps those fragments dislodge and roll through the mountain tracks until encountering river. The downstream transports rock and stone remnants by the waterflow. In this progress, pebbles and sand grains are created by the erosion of rocks and stones.
Removing these scraps to the sea, they submerge then becoming layers of sand grains and pebbles on sea bed. Inside these layers, water and water-borne chemicals intersperse with pebbles and grains. The cementing of those factors contributes to the formation of mudstone. Finally, at low tide, we can witness rocks under the water.