Good Old Cobblestones

President Obama has said that his stimulus plan will provide the “largest investment increase in our nation’s infrastructure since President Eisenhower created the national highway system half a century ago.” It will create hundreds of thousands of job for people rebuilding railways, bridges, and roads. While I applaud his concern about jobs and improved safety, I worry that in the mad rush to pave we may lose a bit of history—the handful of cobblestone roads still dotting Seattle.

A happy group of explorers trodding across one of Seattle’s last cobblestone streets

Between the 1890s and 1910s, sandstone cobbles were a a popular road-paving material in Seattle. The most commonly used varieties came from quarries in Wilkeson, a small town about 45 miles south of Seattle. Workers could easily cut the brick-sized blocks, which provided good traction for horses, although horse shoes did wear down the stone. And the stone cobbles lasted longer and created less of a mess than the mud or wood of the past. (Manhattan also has a few cobblestone streets made from the 450-million year old Quincy granite.)

Quincy Granite cobblestones in Greenwich Village

The Wilkeson sandstone lithified from thousands of feet of sand deposited 40 to 50 million years ago in the Eocene Period when western Washington was flat and subtropical. Palm trees, swamp cypresses, and tree-sized ferns grew in the moist (40-100 inches of rain), bayou-like environment. Waves from an ocean that spread to the west washed ashore on beachfront property, now covered by the urban metropolises along Puget Sound. The only mountains that existed rose far to the east along the Washington-Idaho border. Rivers and streams washed out of those mountains and dropped sand in a coastal lowland dotted with seasonal lakes, swamps, and lagoons.

In addition to sandstone cobbles, brick was another important paving material and can still be found on a few Seattle streets. Local manufacturers used a clay deposited in a proglacial lake, which formed in advance of the ice sheet that covered Seattle during the last Ice Age. A production capacity of 70,000,000 bricks a year made King County the largest producer of paving brick in the country. At one time, these bricks covered streets in Portland, San Francisco, Tokyo, and Los Angeles, as well as roads in Chile, Argentina, and India.

One other local building material, the Index granite, appears on local streets. It formed 34 million years ago during subduction of the Juan de Fuca plate under the North American continent. The Index was used primarily for curbs and can still be found in a few older neighborhoods of Seattle. (One way to get a feel for the age of a neighborhood is to look at the curbs. Old ones are granite; newer ones have concrete with a metal rim, particularly on corners; and modern ones are only concrete.)

According to the last official survey I could find, conducted in 1993, only 93 of these historic streets remain in Seattle; most have been paved over, their stories lost to drivers who don’t want the jarring ride. I do not mind them. I like the connection to the past and consider it a privilege to drive over the ancient cobbles and rustic bricks, although I try to take these roads when no else is in the car with me.

The Politics of Building Stone: Seattle

Twenty years ago today a building stone brouhaha erupted in Seattle.  On that snowy Friday, local newspapers reported that Metro, which managed King County’s sewage treatment and public transportation, would have to pay for, but not use, a half million dollars worth of granite that it had purchased for a new bus tunnel through downtown Seattle.  The reason for the rejection was that King County (Seattle is the county seat) had a policy that it could not use or purchase any goods “manufactured or fabricated” in South Africa because of apartheid.

The conflagration began when Eddie Rye of the Black Contractors Coalition notified Metro about its planned use of a green granite quarried in South Africa.  At the time, the stone, known in the trade as Verde Fontaine, sat in Italy, where it had been shipped for cutting and polishing.  Metro Council executive Alan Gibbs responded that using the stone would be “an affront to the community.”  Officials added that Rye’s notification was the first time Metro had heard of the granite’s origin and that none of the South African had been shipped to Seattle.  Turns out that neither statement was true and that a second South African granite had also been purchased. 

 Travertine and Verde Fontaine

Quarried near Bitterfontein, about 200 miles north of Cape Town, the pine green Verde Fontaine solidified underground over one billion years ago.  The green coloration comes from the mineral chlorite, which forms from the alteration of iron- and magnesium-rich minerals within the rock.  The granite is part of a suite known as Spektakel and were emplaced into supracrustal rock units (metasedimentary and metavolcanic rocks) that most likely exceed two billion years in age. 

After Rye blew the whistle, officials within Metro described how some had known about the origin of the stone but that they thought that so little was to be used that it wouldn’t be a problem.  They also noted that use of the rock technically wasn’t illegal because it was only quarried in South Africa but cut and finished in Italy. King County Council Chairman Ron Sims, a member of the Metro Council, responded ”It was a morally repugnant decision. Somebody should have to account for that. This was no longer a half-million-dollar ‘error.’ It was a conscious decision to defy public sentiment.” 

Accusations continued over the next month ultimately leading to the resignation of Alan Gibbs in late February. ”The buck stops with me,” Gibbs said at a news conference where he read a formal letter of resignation. ”The events of the last few weeks surrounding the issue of South African granite have been an embarrassment to the agency … This episode needs to be put to rest so the agency can move ahead with the important work before us.”  Two weeks after Gibbs’ resignation, an internal review of Metro concluded that Gibbs had not misled the public.  On September 15, 1990, the bus tunnels under Seattle opened, with walls covered in less polemical rock.