Volume 4, Issue 6 (June 2007)
An Overview of the History and Economic Geology of the Natural Cement Industry at Rosendale, Ulster County, New York
The Rosendale region of southeastern New York State is widely recognized as the source of the highest quality natural cement in North America. The North American natural cement industry was founded in 1819 by Canvass White in central New York, but soon shifted to Rosendale where it flourished for over 150 years. By the end of the 19th century, the superior quality of Rosendale cement was known worldwide and was actively used in the construction of some of America’s most enduring landmarks. Rosendale natural cement’s reputation stems from the unique composition of the clay-rich layers of dolostone in the Upper Silurian Rondout Formation from which it is manufactured. 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 exposures resulting from these mining activities have long attracted the attention of geologists for research and education. Production of natural cement transformed extracted dolostone into barrels of cement through a labor-intensive process involving calcination in kilns, cracking, and grinding. Barrels of cement produced were quickly shipped at competitive prices via the Delaware and Hudson Canal, which directly connected the Rosendale natural cement region to major shipping avenues.