A drill core is a core sample: a cylinder of sediment pulled out of the ground and brought to the surface in sections. Read top to bottom and you are reading backwards through time — the further down, the older it is, and the more the world has changed.
A dark, root-bound loam. Everything above this line has been in contact with air and water for at least a few centuries; on a farm it may be only fifty years old.
Sediments settle in the order they arrive, and each layer is a snapshot of a landscape. A band of pale sand is a flood; a band of dark clay is a still, deep water; a bed of shell fragments is a sea that came in and went out again.
Read the whole column and you have a coastline that moved. Read it with a magnet in it and you have the reversal of the Earth's field frozen into the floor. Read it with pollen in it and you have what was growing.
The core is drawn procedurally: each stratum is a band whose colour, grain and thickness are drawn from a seeded sequence, and its edges are irregular, because a real bedding plane is never straight. The scan draws a bright marker line down the column and the read panel follows it.