An overview of the history and economic geology of the natural cement industry at Rosendale, Ulster County, New York

Widely recognized as the source of the highest quality natural cement in North American, the Rosendale region of southeastern New York State was the home to a flourishing natural cement industry for 150 years, having shifted there from its original location of central New York where it was founded by Canvass White in 1819. The superior quality of Rosendale cement was known worldwide by the end of the 19th century and was actively used in the construction of some of America's most enduring landmarks. The unique composition of clay-rich layers of dolostone in the Upper Silurian Rondout Formation from which it is manufactured give Rosendale natural cement its reputation. Miners utilized room-and-pillar techniques to extract this dolostone from strongly deformed strata in the Rosendale region, creating unique bedrock exposures in mines that are something of an engineering marvel. The attention of geologists for research and education has long been attracted by the exposures resulting from these mining activities. Production of natural cement transformed extracted dolostone into barrels of cement through a labor-intensive process involving calcination in kilns, cracking, and grinding. The Rosendale natural cement region was directly connected to major shipping avenues by quickly shipping barrels of cement produced there at competitive prices via the Delaware and Hudson Canal.