Graveyard Geology of Chicago, Part 3: Entrance Pylon, Graceland Cemetery, Uptown Neighborhood (1896)
Much of the geologic interest of cemeteries lies, not surprisingly, in their gravesites—their headstones, markers, monuments, and mausolea. But many burial grounds also feature equally interesting geo-materials in their walls, gateposts, office buildings, and chapels.
Chicago's Graceland is world-famous as the final resting place of some of America's greatest architects (John Wellborn Root, Louis Sullivan, Daniel Burnham, Ludwig Mies van der Rohe, et al.), other Windy City notables (politicians, robber barons, and baseball stars) and Sullivan's exquisite Ryerson and Getty tombs. But the site's Earth-science interest starts right at the front gate, with pylons and other entrance structures designed by Holabird & Roche. This prestigious firm chose to use the same rare igneous selection for all of them.
I confess that that selection, the Mesoproterozoic-era Waupaca Granite, is one of my top three or four architectural-stone favorites. Quarried for a relatively short time about 4 mi (6.4 km) north-northeast of the eponymous community in central Wisconsin, the Waupaca is a rapakivi granite, with hefty alkali-feldspar phenocrysts ringed with lighter-toned plagioclase feldspar. This unusual crystalline composition produces a stunning visual effect, especially when the rock is dressed-faced and polished.
In succeeding photos in this set I'll have much to say about the Waupaca. Here, suffice it to say that in this pylon it's in a rock-faced form that dulls its color but also gives it a rugged, naturalistic appearance.
To learn much more about this site and 200 others in the Windy City, make it your top personal priority to get a copy of my book Chicago in Stone and Clay, described at www.cornellpress.cornell.edu/book/9781501765063/chicago-i...
And to peruse the other photos and descriptions in this series, pay a visit to my Graveyard Geology of Chicago album.
Graveyard Geology of Chicago, Part 3: Entrance Pylon, Graceland Cemetery, Uptown Neighborhood (1896)
Much of the geologic interest of cemeteries lies, not surprisingly, in their gravesites—their headstones, markers, monuments, and mausolea. But many burial grounds also feature equally interesting geo-materials in their walls, gateposts, office buildings, and chapels.
Chicago's Graceland is world-famous as the final resting place of some of America's greatest architects (John Wellborn Root, Louis Sullivan, Daniel Burnham, Ludwig Mies van der Rohe, et al.), other Windy City notables (politicians, robber barons, and baseball stars) and Sullivan's exquisite Ryerson and Getty tombs. But the site's Earth-science interest starts right at the front gate, with pylons and other entrance structures designed by Holabird & Roche. This prestigious firm chose to use the same rare igneous selection for all of them.
I confess that that selection, the Mesoproterozoic-era Waupaca Granite, is one of my top three or four architectural-stone favorites. Quarried for a relatively short time about 4 mi (6.4 km) north-northeast of the eponymous community in central Wisconsin, the Waupaca is a rapakivi granite, with hefty alkali-feldspar phenocrysts ringed with lighter-toned plagioclase feldspar. This unusual crystalline composition produces a stunning visual effect, especially when the rock is dressed-faced and polished.
In succeeding photos in this set I'll have much to say about the Waupaca. Here, suffice it to say that in this pylon it's in a rock-faced form that dulls its color but also gives it a rugged, naturalistic appearance.
To learn much more about this site and 200 others in the Windy City, make it your top personal priority to get a copy of my book Chicago in Stone and Clay, described at www.cornellpress.cornell.edu/book/9781501765063/chicago-i...
And to peruse the other photos and descriptions in this series, pay a visit to my Graveyard Geology of Chicago album.