Thursday, November 3, 2011

Rock Versus Stone: A link to my new blog site

A few people have asked so here's a link to my most recent posting on my new blog site. It's ponders the eternal question of Rock Versus Stone, is there a difference?

Monday, June 13, 2011

New Blog and Web Site

Greetings all. Just a short note to let everyone know that I have moved by blog to my new web site and will no longer be posting at this site.

And here is a link to my new web site.

Thanks kindly for your interest and input in my geology writings.

If you go to the new site, you will see that I am working on a new book, about the natural and cultural history of Cairns (the piles of rock that mark trails), and that I am continuing my blog on building stone. I also hope to broaden the scope of that blog to include more aspects of geology.

David B. Williams

Thursday, March 10, 2011

Seattle Stone: Lobby #2, Smith Tower marble

I would like to return to Smith Tower and look at the other beautiful stone that graces its lobby. It is a classic marble, quarried from Tokeen on Marble Island, just off the west side of Prince of Wales Island in southeast Alaska. Tokeen was the more major of two marble quarries in the area. First to open was Calder, at the north end of Prince of Wales Island but it closed about the time that Tokeen was being more fully developed by R. L. Fox of Seattle. Marble Island was initially called Fox Island.

In the fall of 1903, Fox and several investors started the Great American Marble Company. Apparently the money men had noble aspirations or visions of grandeur. They definitely had other problems, including financial troubles and interpersonal conflicts. Turns out that one investor, Robert Ball, was actually one Charles Mains, a lawyer from Michigan disbarred for shady shenanigans.

Quarry at Tokeen, photo from Alaska State Library Digital Collections

Meanwhile, the owners of the Vermont Marble Company (VMC), in Vermont, had been hearing rumors of “mountains of marble – ‘quantities beyond calculation’ – and of a quality such that ‘no other marble in the world was superior.” Eventually representatives of VMC made it to Marble Island, verified the rumors, and noted a good potential market for the stone. D. H. Bixler wrote in 1908 to VMC “As for the future of Seattle there cannot be much doubt. It seems as though it will surely grow…The pace has been set for first class buildings and any that follow will have to have more or less interior marble.”

With VMC now holding the rights to the marble, they began to develop operations. The initial shipment of 101 tons of marble left Tokeen on July 18, 1909. As many as eight quarries operated with most blocks going to the VMC yard in Tacoma. During the peak years of operation from 1912 to 1915, more than 4,360 blocks were shipped to Tacoma. Cut stone went into buildings from Boston to Honolulu including post offices in Bellingham and San Diego; the Empress Theater in Salt Lake City; the county building in Pittsburgh, and the Pearl Harbor Naval Hospital. In Seattle, it went into King County Courthouse, the Hoge Building, the Bank of California and Smith Tower.

Alaska marble in the Smith Tower

The marble comes from metamorphosed layers of the Heceta Limestone, an Early to Late Silurian (430 to 420mya). Subsequent intrusion of a hornblende diorite metamorphosed the limestone into a marble. Parts of the Heceta is rich in fossils, though none are found in the marble beds. The limestone formed mostly on a shallow marine platform with some deeper water deposition, too.

Smith Tower interior and route to safety

In my next posting, I will show a few photos of the third stone in Smith Tower, a fossil-rich limestone. Very exciting!

Wednesday, February 16, 2011

Seattle Stone: Lobby #2, Smith Tower onyx

In continuing my short tour of Seattle lobbies, I turn to what is one of the best known lobbies in the downtown area. Smith Tower is also one of Seattle’s more famous buildings. Opened on July 4, 1914, the 462-foot tall building was the tallest building west of Ohio at the time. Over the years, the mostly terra cotta clad edifice has borne the brunt of many incorrect claims. As a fine essay on the web site reports, it was never the fourth tallest building in the world, or even outside of New York.

Despite not meeting the aspirations of some, Smith Tower does sport a rather handsome lobby. Two stones dominate, onyx marble from Mexico and marble from Alaska. This post will focus on the Mexican rock.

Onyx is a notoriously confusing stone. True onyx is a variety of quartz. It is sometimes referred to as layered chalcedony or black-and-white agate. The onyx used as building stone is not made of quartz but of calcite and is known as onyx marble. Because such calcareous onyx became popular in the United States through stone quarried near Mexico City, it is also called Mexican onyx, as well, no matter its point of origin. Onyx marble used in ancient Rome and by early Egyptians usually came from Algeria. All onyx marble is popular because of the colorful layering and ability to be highly polished. Color variation depends on the amount of iron and manganese and their oxidation states in the deposits, which become layered as they accumulate in pools.

The Smith Tower onyx panels are from Baja California from an area known as El Marmol. Like all onyx marble, it formed layer by thin layer in springs, in this case cold water springs. Other onyx marbles form in hot springs, too. They can also form as stalactites and stalactites. First quarried around 1893, the El Marmol deposits are about 160 miles southeast of Ensenada and 15 miles from the east coast of the peninsula. (One additional note. After posting this blog, I was reminded that the onyx in Smith Tower is also called Pedrara Onyx, in reference to the company that owned the quarries.)

The Spring at El Marmol (from the Tacoma World web site)

El Marmol achieved a bit of fame for its onyx marble schoolhouse, which was supposedly the only all onyx place of education in the world. Apparently the stones were not polished and by at least the 1950s, the weathered stones were drab and brown. As you can see from this modern shot, it’s not in very good shape.

The schoolhouse at El Marmol (from Tacoma World web site)

When geologist George Perkins Merrill visited the Baja quarries in the early 1890s he found the deposits quite pleasing. “Nothing can be more fascinating to the lover of the beautiful in stones than this occurrence, where huge blocks of material of almost ideal soundness, with ever varying shades of color and veination lie everywhere exposed in countless numbers…The colors are peculiarly delicate, and there is a wonderful uniformity in quality…The rose color is, so far as my present knowledge goes, quite unique and wonderfully beautiful.

The quarry at El Marmol closed in the early 1960s. An article by naturalist Joseph Wood Krutch theorized that it was due to plastic. He wrote “As with so much that is coming in the world, there is a cheap substitute for something dearer and more beautiful.” Fortunately, we can still see the dear and beautiful at Smith Tower.
Next time, I will look at the Alaskan marble.

Wednesday, February 9, 2011

Seattle Stone: Lobby #1

I am starting a series looking at buildings in Seattle. I plan to focus initially on some lobbies that I have long liked. My first is the wonderful art deco Exchange Building. Ironically finished in 1929, the building, as the name suggests, was supposed to house the Northwest Commodities and Stock Exchange. Most of the elaborate motifs feature items that represented Washington state agriculture. It is a lovely building.

For many years, I have taken people to the building on my downtown building stone tour and focused on the exterior Morton Gneiss. If we went on a weekday, I would often go inside and show them the extravagant stone, although I had no clue where the stone originated.
Recently, I was showing Dave Tucker of Northwest Geology Field Trips around Seattle to help him put together a tour for a guidebook he is writing on regional geology. When we stopped at the Exchange Building, his excitement prompted me to try and find out a bit more about the stone. Here's what I learned.

The stone is quarried in Italy near the town of La Spezia, about 14 miles west of the legendary marble quarries of Carrara. The best quarries are on the Tino islands. Initially quarried in the first century and used in religious buildings, the Romans also employed it to pave roads (now that would be wicked cool to see) and in the Luni amphitheater at La Spezia. Quarrying ramped up again after World War II but has slowed down of late. The ancient name was Portovenere and the modern name is Portoro (from Porta oro), with varieties labeled Portoro a macchia larga (large-veined), Portoro di Prima (the best variety), and Portoro a macchia fine (thin-veined).

Geologically, it is part of the vast sedimentary rocks of the Tuscan nappe. The Late Triassic Portoro Limestone is an aragonite mud deposited on a shallow carbonate platform. It is up to 260 feet and consists of black calcite with alternating layers of mixed dolomite and calcite. The complex folding and reworking of the micritic limestone during Miocene deformation, which also metamorphosed the Carrara marble, produced the distinctive and beautiful stylolitic veining that characterizes the stone. Four- to eight-inch-wide shear zones separate undeformed layers up to eight inches thick.
Sorry for the bad coloring. This stone is black. The purple is light reflected from Cherry wood paneling.
The black coloring primarily comes from small amounts of organics in anaerobic environments. Limonite and sulfides produce the yellow banding with dolomite mosaics and hematite forming more violet veins.
The building architect, John Graham Sr., did a splendid job of bookmatching the Portoro panels. He also incorporated Italian travertine and some sort of purple brecciated stone, which I know nothing about. Someday I hope to figure out that part of the story.
Curiously, the Portoro is a stone of warm places, such as northern Africa and Sicily. When weathered, it loses its brilliance and appears "irreversibly opaque, whitened and corroded," according to one study of it. You can see this in Seattle at the entrance to Shucker's Restaurant on 4th Avenue, just north of Seneca.

Next up will be the elegant lobby of the Smith Tower.

Wednesday, February 2, 2011

Louis Kahn and Travertine

Last night, I watched a fascinating documentary about the iconoclastic architect Louis Kahn. As the title implies, My Architect: A Son's Journey, follows Kahn's son Nathaniel as he attempts to discover the father he didn't know. Kahn was one of the greatest and most complex architects of the twentieth century. He is best known for his work in the United States, which includes the Kimball Art Museum in Dallas and the Salk Institute in La Jolla. He also designed astounding buildings in Bangladesh and India. What he was less known for was that he had three families, one with his wife and two through long-term affairs. All three produced children. The movie is well worth watching not only for Kahn's fascinating life but also for his stunning architecture.

What I like best about his work is his use of geometric shapes. He punctuates his walls with angles and arches and circles, allowing an ever changing interplay of light and shadow. Each design brings the buildings to life as they change shape throughout the day. His use of geometric shapes also connects his buildings to the landscape, not necessarily in an organic way, but in a way that continues the weaving of the ephemeral and the permanent.

And finally, Kahn appears to have been quite the fan of travertine. His use of it at the Salk Institute foreshadows and seems to have inspired Richard Meier's use of the stone at the Getty Museum. Below are some photos I found on the web that to me are some of the most notable uses of travertine. I hope you'll agree.
Kimball Art Museum (from the Southern Live Oak blog)
Kimball Art Museum detail (from flickr)
Salk Institute (from Daily Icon)
Salk Institute details (from Daily Icon)
Salk Institute seats (from Premier Green)
Yale Museum for British Art (from flickr)

Tuesday, January 4, 2011

The Crocodile and the Countertop

Italian paleontologists have been on a roll of late, and they haven’t even had to go out in the field. Late last year came reports of the dinosaur in the duomo. Now, comes the tale of the countertop crocodile. The new story begins in 1955 in Portomaggiore (Ferrara, Italy), when stonecutter Mr. S. Pasini observed what he thought were fossil bones in a block of yellowish-red limestone destined for a countertop. After the cutting the block into four slabs, Pasini saved the stone. A year later paleontologist Piero Leonardi described the fossil as a cross section of a crocodile he called the “Coccodrillo di Portomaggiore.”

Cross sectioned slabs from Gondwana Research (In Press, available online August 7, 2010) Scale bar = 20cm.

Two of the slabs eventually ended up at the Museo Geologico Giovanni Capellini in Bologna, where they they sat undisturbed until 2009 when paleontologists Federico Fanti and Andrea Cau studied them. They concluded that Leonardi’s crocodile was a new species and the oldest member of the Metriorhychidae, a diverse and curious group of marine crocodilians, which existed from about 171 to 136 mya. They were fierce, pelagic, piscivorous predators. Fanti and Cau named the new species Neptunidraco ammoniticus or “Neptune’s dragon from the Rosso Ammonitico Veronese Formation.”

Neptunidracos' streamlined body, Illustration by Davide Bonadonna

Neptunidraco is the oldest known member of the Metriorhychidae group and did not look like any modern crocodile. They had streamlined skulls, a vertical tail, and a hydrodynamic body, all features well adapted to a marine lifestyle. Cau describes Neptune’s dragon as “more like a dolphin than a croc.” Based on their anatomy and teeth, they ate small, swift fishes. They may have ventured onto land to lay eggs. Later Metriorhynchids were more robust and could have eaten armored fish and large marine reptiles.

Happy geologists Cau and Fanti (from Cau's blog)

Rosso Ammonitico, also known as Verona Marble, is a Middle Jurassic age, generally reddish limestone rich in ammonites, hence the name. It formed in deep water as fine grained sediments settled into the Tethys Sea on the margin of Gondwanaland. The specific quarry was near Sant’Ambrogio di Valpolicella, about 10 miles northwest of Verona. (The fossil-rich slabs come from a more yellow part of the quarries, known as “ammonitico giallo.”) Used since Roman times, Rosso Ammonitico can be found at the Arena in Verona, the Battistero in Parma, the Palazzo Ducale in Venice, the Cathedral in Cremona, and the Galleria V. Emanuele in Milan. (On the VertePaleo list serv, the reporting of this story led to some amusing anti-limestone-countertop comments. When I was in Bloomington, Indiana, working on my chapter on the Salem Limestone, I remember seeing builders touting the limestone countertops of a new rental units. To each his/her own.)

Ammonite from Baptistry (Battistero) of Parma (from Wikicommons)

The publication of the story apparently has ruffled a few feathers in Italy. On Andrea Cau’s blog, he notes that one famous Italian geologist offered critical comments on the discovery (saying it wasn’t truly a discovery since the fossil had been known since 1955) and the bigger implication that it provides a new understanding of the evolution of these intriguing marine crocodiles. Cau believes that the conflict results in part from a generational difference and a clash of paradigms, where the young upstarts are willing to reconsider, restudy, and reevaluate past concepts and specimens. He recognizes that their discovery does not change the world but it “is a beautiful piece of a huge mosaic called paleontology.” (Translation from Google Translator.)

Moreover, isn’t what Cau and Fanti did part of what makes science so appealing and such a valuable way to understand the world around us. We should applaud them for looking carefully, for struggling with understanding what they saw, for asking questions, for drawing new conclusions, and for learning from those who came before. And yes, their new discovery is a thing of beauty.