Beach rock - the formation of sedimentary rock

Beach rock - the formation of sedimentary rock - You can find many pebbles here. It is believed that they came from an ancient river which brought them downstream accompanied by fine particles, such as sand and mud. The pebbles settled when the water ran into the sea. As time goes by, these pebbles will consolidate with the fine sediments and will eventually turn into sedimentary rock. Before these sediments become sedimentary rock, it is called beach rock. Can you guess which kind of sedimentary rock these beach rocks will become?