In addition to taking some great pictures, Marty does a wonderful job of digging up and presenting background information. Fiborn Quarry was one of the largest early 20th century quarry operations in the Upper Peninsula, and Marty’s Fiborn Quarry set (slideshow) begins:
Fiborn Quarry was created by a partnership of the Duluth, South Shore & Atlantic Railroad in 1904. This small company town was built to house the workers (homes and a boarding house), offer a school and a general store. The operations consisted of the quarry plant, crusher house and steam engine shop.
Marty goes on to tell you about the role of limestone in the history of the UP, and he also links over to the Michigan Karst Conservancy. In addition to extensive information on the history of Fiborn (be sure to click the little photos at the bottom of the pages too), the MKC tells you about karst:
Karst is a term that was first applied to a plateau region of the Dinaric Alps in Yugoslavia. It is now used to describe similar regions throughout the world that have features formed largely by underground drainage. Karst terrains are characterized by caves, steep valleys, sinkholes, and a general lack of surface streams because drainage is underground…
What does this have to do with Michigan, a land literally scoured by glaciers, a land covered with glacial clay, sand and gravel? Surprisingly, Michigan contains some areas of true karst. They are limited in extent, but this rarity increases their interest and importance. There is also considerable variety in Michigan karst areas: gypsum karst is found in Kent and Iosco counties; a significant amount of surface drainage goes underground in Monroe County, and reappears at “blue holes” in Lake Erie; spectacular sinkholes and earth cracks are found in Alpena and Presque Isle counties; and the broad band of outcrops of the Niagara Escarpment in the Upper Peninsula hosts a number of karst sinks, springs and caves.