Pebbles are a common sight at many beaches but have you ever wondered why these little round and spherical shaped stones are found on the coastline? Well, there are a lot of factors that contribute to their occurrence in the coastal areas. These include the geology, weather and the shape of the coastline. These are basically the reason why you find sand on certain beaches and pebbles on the others. Fine particles of sand are seen on the beaches where there is low energy environment while those with higher energy encompass large particles.
Pebbles seen on the beach are of different type. Some of these are volcanic, some non-volcanic while some are granite. These pebbles have come from the bedrock lying next to the beach. Each rock seen on the beaches had once been a part of the bedrock before it broke down and became an individual entity and so were these small pebbles.
Thousands of years ago as the glaciers melted, they hit the bedrocks and several small stones of different shapes and sizes were formed each time they did. These stones eventually got settled on the sea shores. As they came into contact with the sea waves and rolled up and down numerous times, they became more refined and rounded. These polished stones are commonly known as pebbles.