The Sugar Run Dolomite is a

geologic formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. Its largest metropolitan areas include the Chicago metropolitan area, and the Metro East section, of Greater St. Louis. Other smaller metropolita ...

. It is a finely-bedded

dolomite Dolomite may refer to: *Dolomite (mineral), a carbonate mineral *Dolomite (rock), also known as dolostone, a sedimentary carbonate rock *Dolomite, Alabama, United States, an unincorporated community *Dolomite, California, United States, an unincor ...

, preserving

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

dating back to the

Silurian The Silurian ( ) is a geologic period and system spanning 24.6 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the shortest period of the Paleozo ...

period Period may refer to: Common uses * Era, a length or span of time * Full stop (or period), a punctuation mark Arts, entertainment, and media * Period (music), a concept in musical composition * Periodic sentence (or rhetorical period), a concept ...

. This formation is named for the Sugar Run stream in Joliet, along which it is well exposed. The dolomite is off-white/grey on freshly cut surfaces, but over time oxidizes to a distinctive cream yellow color, due to trace presence of iron. It is a member of the Niagran series.

Use in architecture

This formation has been quarried for building material since the mid-19th century, sometimes sold under the misleading trade name of "Athens marble". It is also known as Joliet or Lemont limestone. It was used widely in the construction of many Chicago homes and buildings from the 1850s-1880s, including the famous

Chicago Water Tower The Chicago Water Tower is a contributing property and landmark in the Old Chicago Water Tower District in Chicago, Illinois, United States, that is listed on the National Register of Historic Places. Built to enclose the tall machinery of a powe ...

. By the 1890s, it fell out of fashion as a building material in favor of more durable

Indiana limestone Indiana limestone — also known as Bedford limestone in the building trade — has long been an economically important building material, particularly for monumental public structures. Indiana limestone is a more common term for Salem Limestone, ...

References

* Silurian Illinois {{Illinois-geologic-formation-stub

Use in architecture

See also

References