A "Chicago in Stone and Clay" Companion, Part US-H: The Tuscan Order on Parade | Union Station (1925)
This series complements my award-winning guidebook, Chicago in Stone and Clay: A Guide to the Windy City's Architectural Geology. Henceforth I'll just call it CSC.
The CSC section and page reference for the building featured here: 9.2; pp. 142-144.
Looking northward, along the eastern elevation.
And finally we're outdoors. This oblique view of the station's Canal Street facade shows its grand Tuscan-order colonnade.
The Tuscan style resembles the Doric, but it's even less adorned, with unfluted column shafts.
And it's these columns that are one of Chicago's finest examples of the effective use of America's most widely distributed architectural rock type, the Salem Limestone.
Note that the shafts are not monolithic, but rather are composed of tall drums mortared together. This technique of modular column construction is an ancient one that goes back to classical Greece and no doubt even farther.
Regarding the stone itself, the Salem has many virtues, but its finely granular texture does not permit high-gloss polishing. Nevertheless, it can be shaped, carved, and smooth-sawn very readily. Here the flat and buff-colored stone surfaces impart the perfect stately-and-restrained effect.
The Salem, known in the building trades as "Bedford Stone" and "Indiana Limestone," is quarried in southern portion of the Hoosier State. Petrologically speaking, it's a grainstone and biocalcarenite composed of small fossils (whole forams and invertebrate fragments) in a matrix of calcite cement. It formed in a warm, shallow-marine environment of lagoons and tidal channels in the Mississippian (Lower Carboniferous) subperiod, some 340 Ma ago. At that point, much of the American Midwest was covered by an epeiric (continent-covering) sea.
For more on this site, get and read Chicago in Stone and Clay, described at its Cornell University Press webpage.
The other photos and discussions in this series can be found in my "Chicago in Stone and Clay" Companion album. In addition, you'll find other relevant images and descriptions in my Architectural Geology: Chicago album.
A "Chicago in Stone and Clay" Companion, Part US-H: The Tuscan Order on Parade | Union Station (1925)
This series complements my award-winning guidebook, Chicago in Stone and Clay: A Guide to the Windy City's Architectural Geology. Henceforth I'll just call it CSC.
The CSC section and page reference for the building featured here: 9.2; pp. 142-144.
Looking northward, along the eastern elevation.
And finally we're outdoors. This oblique view of the station's Canal Street facade shows its grand Tuscan-order colonnade.
The Tuscan style resembles the Doric, but it's even less adorned, with unfluted column shafts.
And it's these columns that are one of Chicago's finest examples of the effective use of America's most widely distributed architectural rock type, the Salem Limestone.
Note that the shafts are not monolithic, but rather are composed of tall drums mortared together. This technique of modular column construction is an ancient one that goes back to classical Greece and no doubt even farther.
Regarding the stone itself, the Salem has many virtues, but its finely granular texture does not permit high-gloss polishing. Nevertheless, it can be shaped, carved, and smooth-sawn very readily. Here the flat and buff-colored stone surfaces impart the perfect stately-and-restrained effect.
The Salem, known in the building trades as "Bedford Stone" and "Indiana Limestone," is quarried in southern portion of the Hoosier State. Petrologically speaking, it's a grainstone and biocalcarenite composed of small fossils (whole forams and invertebrate fragments) in a matrix of calcite cement. It formed in a warm, shallow-marine environment of lagoons and tidal channels in the Mississippian (Lower Carboniferous) subperiod, some 340 Ma ago. At that point, much of the American Midwest was covered by an epeiric (continent-covering) sea.
For more on this site, get and read Chicago in Stone and Clay, described at its Cornell University Press webpage.
The other photos and discussions in this series can be found in my "Chicago in Stone and Clay" Companion album. In addition, you'll find other relevant images and descriptions in my Architectural Geology: Chicago album.