Geology

In advance of the drillers we did look into this. They are after all proposing to go down a good way (75 metres down!). Our house is built of 'marlstone' (a warm orange limestone-plus-sandstone mix) with some cotswold oolitic limestone. There is an old quarry at the edge of the village. But we did get the gelogical survey map for the area (from the London Natural History museum) and these stone layers are remarkably thin, at any rate much thinner than 75m! Apart from this we are most likely on various forms of 'clay'. The drillers are not concerned, indeed on the whole prefer stone, but we shall see. They do not like running sand, nor it seems chalk, nor artesian water - meaning a spring I think).

I note that 75m down is more than half-way down to sea level here (we are at 130m)!