A "Chicago in Stone and Clay" Companion, Part AG-A: In the Unlikely Event You Encounter an Architectural Geologist, Avoid Eye Contact and Walk Purposefully Away
This series complements my award-winning guidebook, Chicago in Stone and Clay: A Guide to the Windy City's Architectural Geology.
They're rare, but they're out there, wandering the city streets.
This specimen is typical: an old man with a Newberry Library baseball cap slightly askew, mumbling to himself and photographing a skyscraper at the range of 8 in (20 cm).
He may look harmless, but on no account ask him what he's doing lest you suddenly find yourself transported to the Neoproterozoic era.
(Actually, I took this shot to demonstrate the amazing reflectivity of the highly polished Hägghult Diabase cladding on the side of Chicago's 1958 Borg-Warner Building.
The Hägghult Diabase—non-American geologists call it Dolerite instead—goes by the trade name of "Black Swede" and "Black Swedish Granite." It most certainly is not a granite, but does indeed hail from Sweden's Skåne province. A darkly beautiful intrusive igneous rock, its age range of 1.6-0.9 Ga straddles the Mesoproterozoic-Neoproterozoic boundary. Note its glittering mafic-mineral crystals in the reflecting surface.
Incidentally, the becolumned, Beaux Arts edifice across Adams Street is the Peoples Gas Building (1911). Its massive monolithic columns were fabricated from blocks of Massachusetts-quarried Cape Ann Granite, Middle Silurian in age.)
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 AG-A: In the Unlikely Event You Encounter an Architectural Geologist, Avoid Eye Contact and Walk Purposefully Away
This series complements my award-winning guidebook, Chicago in Stone and Clay: A Guide to the Windy City's Architectural Geology.
They're rare, but they're out there, wandering the city streets.
This specimen is typical: an old man with a Newberry Library baseball cap slightly askew, mumbling to himself and photographing a skyscraper at the range of 8 in (20 cm).
He may look harmless, but on no account ask him what he's doing lest you suddenly find yourself transported to the Neoproterozoic era.
(Actually, I took this shot to demonstrate the amazing reflectivity of the highly polished Hägghult Diabase cladding on the side of Chicago's 1958 Borg-Warner Building.
The Hägghult Diabase—non-American geologists call it Dolerite instead—goes by the trade name of "Black Swede" and "Black Swedish Granite." It most certainly is not a granite, but does indeed hail from Sweden's Skåne province. A darkly beautiful intrusive igneous rock, its age range of 1.6-0.9 Ga straddles the Mesoproterozoic-Neoproterozoic boundary. Note its glittering mafic-mineral crystals in the reflecting surface.
Incidentally, the becolumned, Beaux Arts edifice across Adams Street is the Peoples Gas Building (1911). Its massive monolithic columns were fabricated from blocks of Massachusetts-quarried Cape Ann Granite, Middle Silurian in age.)
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.