Most people think of big holes in the ground when they think of "gravel pits/quarries" but there's a bit more to them than that, here is a section of the processing plant (they are nearly all built on the same lines) where the sand, silt and gravel are separated after that the sands are separated into soft sand, sharp sand and silt (waste product), the gravels are sorted into different sizes ie: 40mm, 20mm, 10mm and sometimes 6mm depending on customer demand, anything above 40mm and in some cases above 20mm are sent to the crusher to be crushed and sent through the system again to come out the