Local Geology

Reptiles in the village!

Have you heard about the Gigantic Pencaitland Crocodile, or the Spilmersford Shark? Nevermind the relatively modern dinosaurs!

Evidence of these has been eroded away since the last ice age. By digging down 25 meters or so, there are signs of the times when we were joined at the hip with Africa, a mere 250 million years ago. The land was largely submerged leaving tropical swamps, similar to mangrove areas today; good for crocs and sharks!

Plant and land life was abundant in these times, but burrowing further would have revealed Amazon-type river delta – still hot and tropical, but on the edge of hinterland and Himalayan-type mountains. Ground cover and vegetation has not arrived and the environment is hostile. On a bit further and the rock changes to reveal the times when volcanoes were active, including sixteen lava flows. Further still and we reach semi-desert conditions.

This digging has already been done by the British Geological Survey team. In 1967, a borehole was sunk almost 1km into ground at Spilmersford at the east of the village. Old Red Sandstone from the Silurian Age was found at 933m below ground level, below volcanic lava flows similar to the volcanic rocks of the Garleton Hills nearby. Peeling back the layers reveals oil, gas, coal, sand and limestone found within the seams above. Extraction of some of these has helped shape the land and our community.

Volcanic eruptions in the Carboniferous Period, 362 – 290 million years ago, and continued deposition of sedimentary layers including the limestones and coal seams, led to the principal formation of the current land mass.

This was later subject to carving by the various ice ages. The last ice age left behind a blanket of mixed up boulder clay when it melted around 10,000 years ago. It contained sand, clay and stone boulders and it levelled out the ground to its present flattish state.

For more information, you can download these geology maps of East Lothian:

• Geology map of East Lothian.
• Cross-section geology map of East Lothian.
• Spilmersford borehole.

Coal mining

In the heyday of coal mining, there would have been at least eight mines working in the neighbouring landscape producing in the region of 100,000 – 150,000 tonnes of coal per year. Most of this would have been hauled by steam trains to the ports of Leith, to Edinburgh and to Lauderdale and the south. Almost all of these shut before World War I. The last deep mine to shut in the county was at Chancellorsville on West Mains Farm, east of Ormiston.

If you are interested in the local geology, from coal and sandstone to iron and fossils, please click here.