Box work is a type of formation
found in cave
s. It consists of sheets of iron oxide
sticking out of the walls or ceilings of a cave. It's called boxwork because the sheets are usually found near each other, and parallel
, looking like a series of boxes sticking out of the wall. It's one of the more common cave formation
s encountered while caving
, and it is quite cool to find something looking so manmade jutting out of the wall of a cave.
Box work forms when soft rock containing iron deposits is worn away in the process of forming a cave, leaving the harder iron behind. I believe, but cannot confirm, that the box shape is because the softer rock is usually iron pyrite, which forms cubic crystals.