The seaglass and sea pottery washing and rolling around in the sand and pebbles around our coast, can be centuries old. They wear down over the years, getting smaller as they rub and tumble against the rocks and pebbles on our beaches. The rocks and pebbles, however, that they tumble against here in North Devon, are about 400 million years old.
These tiny, shiny, wet pebbles that you walk over, were originally laid down as sand sediment in coastal conditions, way back in time, when the earth was a totally different place. Continents are constantly on the move, pushed and pulled, sliding over the earth. The area of land that we call North Devon was part of a larger continent and we were situated right down near the Equator.
The sand built up over time and was gradually buried thousands of meters deep under layers of muddy sediment and soil. Over millions of years of extreme pressure, this sand was gradually formed into rock hard sandstone.
The upper layers of overlying younger soil, clay, mud and slate rock were eroded over time, to expose these sedimentary Old Red Sandstone rocks. The plate carrying most of Europe slowly moved back north to where we are now.
These sandstones were first studied in detail here in Devon in the 1830s and the whole of this particular geological time period was named the Devonian Period.
The rock cycle is continuous, with wind, water, ice and wave action cutting back into the cliffs, where chunks are broken off and rolled into rivers or the sea. These chunks of rock are again broken down into pebbles and worn smooth over the years, gradually turning into sand again.
Whenever you are beside a cliff, you are surrounded by the Earth's history. It's always interesting getting up close to these rocks, as they have a story to tell and you may feel their silent energy locked deep within. If there's an old rubbish dump above you, also being eroded into the sea, you may also be surrounded by beautiful, ground down, vintage seaglass history ...and that's an added bonus.