Sentence:  Once in a while Werner tows Jutta as far as the entrance to Pit Nine, the largest of the mines, wrapped in noise, lit like a pilot at the center of a gas furnace, a five-story coal elevator crouched over it, cables swinging, hammers banging, men shouting, an entire <WSD>mapful</WSD> of pleated and corrugated industry stretching into the distance on all sides, and they watch the coal cars trundling up from the earth and the miners spilling out of warehouses with their lunch pails toward the mouth of the elevator like insects toward a lighted trap. 
Meaning of the word marked with <WSD> tags:  A quantity (of something) that forms a map or a map-like image.