The episode title does have a double meaning – the rocks and deposits that lie beneath us have a very strong controlling influence on what we do to our planet and what we don’t do and what we shouldn’t. They may take time to assert that influence but the fact is that ultimately nature will always win any fight we pick with it. I’m going to be talking about the experiences we humans have in interacting with the ground beneath our feet – the opportunities it presents and the hazards it poses, ones that can be mitigated and ones that in any practical sense, can’t.

There are so many places across the north of England that show us how the human race has depended on rocks that I felt this topic needed at least 2 episodes. The last episode explored the origins of stone axes, copper, iron and lead ores, coal and graphite. This one visits 6 more places that have examples of very different uses for the geological resources of our planet. First we are off to the City of Durham.

It is difficult to overstate how dependent we humans are on the resources geology – rocks – provide. It was rock that first provided prehistoric people with shelter and with the raw materials for their tools and weapons, jewellery and pots. Stones built their monuments and the tombs for their dead. Making fire is one of the things that distinguished us humans from animals – we struck two rocks to take that evolutionary step. Our ancestors’ connection with the landscape and its rocks was deep and all-pervasive.

They recognised the hardness and sharp edges of flint, chert and quartz for cutting tools. The durability of hard rocks for hammers and axes. Stones with the right roughness were used for milling grain or sharpening tools. Rocks with layers were skilfully split into slabs and panels. Clay was used everywhere to make pottery.

Local ores were prospected, mined and smelted and then turned into weapons, utensils and ornaments. Coal and peat were exploited as fuels for homes and industry. Rocks permeated early societies’ rituals and aesthetics: white gypsum on henges, ochre and hematite as pigments. The fact that these stones were traded so widely and valued so highly underlines their esteem.

It’s tempting to think humans are less dependent on rocks today but we are not, we just use far more of them differently. From the environmental pariahs: coal, oil and gas; to the steel, copper and glass in our buildings; crushed rock, sand and gravel and gypsum in our infrastructure; limestone in toothpaste; salt in food; and barium in medicines. Without these and many others, especially the critical and rare minerals we are using more of in our digital devices, our lives would be a lot less civilised. We just have to find ways of using the Earth’s limited resources much more responsibly.