Its time to get to grips with how people and rocks connect. And first in ancient societies. So we will be occupying the overlap – more no-mans-land – between geology and archaeology. The two subjects - just like rocks and humans - are inextricably linked. Our ancient ancestors relationship with their natural landscape – that is its rocks – was intimate. Rocks and sediments provided them with shelter, water and tools. It influenced how they used the landscape – their settlements and defences and routeways. Rocks were the foundation of their beliefs and rituals.

Our tectonic plates continued their erratic waltz north. All the while billions of tonnes of sediments were deposited, turned to rock, tilted up here and there and then eroded away. 60 million years ago lava started to pour out of an enormous rift that was to become the Atlantic Ocean. North America and Europe have been drifting apart ever since. 2.6 million years ago the Earth‘s temperature began to fluctuate again; we cooled and then warmed, repeatedly – the Ice Age – and we are still in it. Ice caps extended to lower latitudes, glaciers grew and then retreated and as they did trees and plants recolonised the landscape. Humans emerged and began to exert their influence on the county, clearing forests and settling in the valleys – but that’s for next time

This episode starts with injection of molten rock across northern England a rock that is responsible for a huge chunk of our tourist economy. Then it takes a tour of hot deserts, evaporating salty seas, and finally our secret bit of every fossil hunters dream rock. On the way we’ll hear about plots to blow up a famous stone circle, dispose of nuclear waste, a mass global extinction and a more recent awful tragedy. Sounds dismal, but its really not!