Would you believe it

Just got a detailed copy of the British Geological Survey. Would you believe it, my house is built on chalk. The Lewes Nodular Chalk Formation, a tiny band no more than a few hundred yards long in the middle of the gravel and sand that makes up London, and I'm slap bang in the middle of it. Wonder how deep down it is. Perhaps I should start digging the garden up.

first you will have to shovel your flint chippings away

That's true. Funnily enough a couple of months ago the house at the end of the road was renovated, and they dug a huge 3/4 metre square pit in the front garden, it was a good 8ft deep . No idea what it was for but I had a good (unfruitful) rummage in it for artefacts. It was all dirt, not a sign of chalk, so the chalk layer must be down pretty deep.