September 2010

Stories in Stone: Travels Through Urban Geology, by David B. Williams; Walker & Company, New York, 2009, $26.00, hard cover, 260 pp. Includes a ten page Index, eighteen pages of Chapter Notes and a five page Glossary. Illustrated with two to three black and white photographs in each of the ten chapters.

The Beauty of Stone

I have to start this review by revealing that I enjoyed Stories in Stone so much that I read a number of chapters more than once. Having said that, let me give you an overview of the content.

A geology major in college, Williams found his life taking him away from the abundant rock exposures of the west to the mega-cities of the east where geology was to be found in the building stones of buildings both old and new. Stories in Stone is the natural outcome of William’s background, passion and circumstance. Each of the ten chapters focuses on a specific stone used in building. In some cases the stone is a structural element meant to support an entire structure. In other cases the stone becomes purely an ornamental skin. In either case, the description and use of the material is only a part of a much bigger story.

Each chapter of Stories in Stone includes a geology lesson describing how the particular stone came to be and where it occurs. All chapters have a history lesson as well - many of the stones have been quarried since ancient times. William’s descriptions of the quarrying methods, both ancient and modern, are fascinating. The paleontologically inclined need not despair as some of the building stones contain fossils or are fossils in their own right. William’s relates interesting and potentially deadly failures when even modern engineers used the right stone in the wrong application.

The ten chapters of Stories in Stone address: New York Brownstone, Boston Granite, Carmel Granite, Minnesota Gneiss, Florida Coquina, Indiana Limestone, Colorado Petrified Wood, Carrara Marble, East Coast Slate and Italian Travertine. William’s chose New York Brownstone to begin perhaps because it is well known. The term “Brownstone” is used to describe row houses in the east. This brown sandstone, colored by iron, was used as a facing stone from the mid to late 1800's. The 200 million year old sandstone was often considered unattractive but it was still commonly used. Williams quotes Pulitzer Prize winning author Edith Wharton, “the city ‘was cursed with its universal chocolate-coloured coating of the most hideous stone ever quarried’”(3).

William’s points out that today’s surviving brownstones are not all in pristine condition - some because of poor maintenance and others because of poor building practices. I found it interesting to learn how building practices could effect the durability of the stone. Since the sandstone is a sedimentary rock, it was deposited in layers. As long as a builder laid the stone with the bedding planes in their natural position all was well. Since the stone was used as a veneer, it was easier for some builders to split the stone thin along the bedding planes and install it with the plane vertical - this allowed the stone to draw in more moisture and spall with the freeze -thaw cycles. Another issue for durability was the use of “green” stones or ones that hadn’t been aged in the quarry. Once quarried, minerals in the stone needed to leach out slowly before use. When this was not done properly (by rushing to meet market demand) the stone could also spall over time. Today, some of these classic brownstones are being restored but not with newly quarried stone. They are being covered in brown stucco.

There’s quite a bit on the paleontology in this chapter since exposures in Massachusetts had preserved dinosaur tracks. The early pre-Darwin discoveries were thought to be the tracks of Noah’s Raven. Samples were shown to professor and geologist Edward Hitchcock of Amherst College who declared them to be those of birds. Hitchcock went on to write the earliest paper about the stone bird tracks in America. This was only a few years before dinosaur body fossils became known in Europe. Despite the likely connection to dinosaurs, Hitchcock maintained his belief that the tracks were made by birds.

Brownstone fell out of style by the mid 1890's when fashion dictated that white was the color of choice. This was driven by the use of white and classic Greek style in the 1893 World’s Columbian Exposition in Chicago. The change in style boosted the use of one of the most widely used building stones in America - the Salem Limestone of Indiana. The Salem was formed 330 million years ago in the inland seas of the Mississippian. As Williams explains, limestone of this age is even exposed in the Grand Canyon although it is known by a different formation name. The Salem Limestone has been the building stone of choice for government buildings around the country so you will see it in Post Offices and Courthouses almost everywhere. The stone was also popular with the wealthy. Both Cornelius Vanderbilt’s “The Breakers” mansion in Rhode Island and also George Vanderbilt’s Biltmore House in North Carolina used the Salem Limestone (130).

In his geological description, Williams explains the depositional environment and the faunal assemblage. The predominant fossil materials found in these rocks are bryozoans, brachiopods and crinoids. You are not likely to see the fossils in buildings made of the Salem Limestone. Inclusion of macro fossils in the stone makes it less desirable for building from both an appearance and durability standpoint. Williams reports that some areas that are quarried produce stone formed in a lagoonal setting. This material is full of the fossils of microscopic Foraminifera.

The old and new quarrying methods provide an interesting section in the story of the Salem Limestone. Beginning with hand drilling and blasting with black powder to the modern use of diamond belt saws, air bags and giant front loaders. Only the roughing work is done at the actual quarry. Finishing and finer detail work is done in a mill at another location. The mill has huge diamond saws for slabbing plus lathes for turning columns. Intricate work is still done by hand. Some of the more unsettling tales related by Williams include those of injury or death from quarrying operations. Workers who made a career in the quarries often were deaf from the noise of early machinery and pounding hammers. That was the good news. Others less fortunate were crushed by falling blocks of quarried stone or killed by snapping cables or wire saws. Modern quarry operations are much less hazardous but it is still a very dangerous job.

Another building stone that got a boost from the revival of white as classic and elegant was the Italian Carrara Marble. As Williams relates, this is the stone of Michelangelo. Carrara is a metamorphic stone formed from 200 million year old limestones. The ultimate creation and exposure of the Carrara is a complicated story involving plate tectonics and mountain building around the Mediterranean.

While the chapter on the Carrara details the ancient and modern quarrying and transport methods, the modern failures in using this stone were the most fascinating. Those of you who collect rocks or fossils from outcrops are well aware that stone is not uniform across even short distances. This is just as true with the Carrara. Williams points out that Michelangelo chose stone for sculpting for its luminescence. Marble with larger crystalline grain structure tends to allow more light penetration causing the finished piece to almost glow in strong lighting. A finer uniform grain structure is more important for building. While that is interesting, the expansion and warping of the Carrara was something I had not anticipated. Apparently , neither did some famous architects and engineers in the 1970's. Carrara marble was chosen as a facing stone for the Standard Oil corporate headquarters in Chicago. Although the designers devised an anchoring method for the 44,000 panels that would allow for movement of the slabs.

This wasn’t sufficient. Within a year, a 350 pound slab fell from the 82nd story damaging a neighboring building. The next slab to fall crushed a car. After much testing, it was found that some of the slabs could warp as much as 1-1/8 inch - far beyond the design limits of the anchoring system (154). By 1988 Amoco, the incarnation of Standard Oil at that time, began replacement of the marble with granite. Williams explains that the expansion, contraction and warping are caused by the inherent asymmetric crystalline structure of calcite (173).

The most recently formed building stone covered in Stories in Stone is Travertine. When cut and polished, creamy white Travertine contains obvious linear voids and pockets making its appearance distinctive.

Williams explains the formation of Travertine in hot springs including those found in Yellowstone Park. There is a Cincinnati and outer space connection to Travertine. As Williams relates, during the 1992 GSA Convention in Cincinnati, Robert Folk presented a talk, “Bacteria and Nannobacteria Revealed in Hardgrounds, Calcite Cements, Native Sulfur, Sulfide Minerals and Travertine” (199). Folk’s nannobacteria appear as microscopic spheres and rods smaller than more well known bacteria. Geologists began researching Folks claims and indeed found “nannobacteria” (now with the more accepted spelling of nanobacteria (200). Not all scientists agree that they are seeing fossilized bacteria but these tiny objects are even now being implicated in other mineral forming processes including kidney stones (213). The outer space connection is with the Antarctic Martian meteorite (ALH84001). Folk’s talk inspired the NASA scientists who interpreted structures in this object as nanobacteria and proof of life on Mars (201).

I had not known before reading Stories in Stone that the Roman Colosseum is faced with Travertine. The Romans had found that buildings constructed with readily available volcanic Tuff did not weather well so they faced them with Travertine (203). Perhaps the most prominent modern application of Travertine is the Getty Center in Los Angeles. Williams relates why Travertine from Italy was selected as the facing stone for the Getty. Part of its appeal was it presented a more “organic” look and blended well with the environment (216). The stone is purposefully used as art in prominent places on the building. Included in this stone as art theme are those containing fossil plants.

I have only highlighted a few chapters in this review to give you a snapshot of Stories in Stone. Among other chapters is one where you’ll find a gas station constructed of petrified wood and of its interesting connection to Phillips Petroleum. And too, there’s the Florida fort constructed of Coquina that kept the Spanish safe from the English in 18th century St. Augustine. Then there’s the rise and fall of the American Slate industry from blackboards and roofing slates to oblivion. In my opinion, The Morton Gneiss of Minnesota is the most colorful of the building stones described and the oldest at over 3 billion years. The Cincinnati and Suburban Bell Telephone Company building in downtown Cincinnati used the Morton Gneiss.

My only dissatisfaction with Stories in Stone is minor and pertains to the photographic illustrations. The author’s text descriptions of stones and quarrying methods painted great visual images in my mind but I was often longing for an accompanying photograph to augment the text. I am sure that publishing costs prohibited the use of color photographs but the addition of just a few would have greatly improved the visual impact of some of the building stone Williams discussed. My last criticism is with the quality of two photographs in particular. These were so dark that the point of interest in them was almost impossible to see - the slate tombstone at King’s Chapel Burying Ground in Boston (193) and the fossil leaf in Travertine at the Getty Center (218). The leaf photo was a minor issue. The fine detail in the tombstone engraving was more important as it has been rumored to have inspired Nathaniel Hawthorne to create the character Hester Prynne in The Scarlet Letter (193).

Readability - Stories in Stone is an easy to read book suitable for high school level and up. Unfamiliar architectural and geological terminology is covered in the Glossary.

On the Upside - The beauty of Stories in Stone is that Williams has broadened the scope beyond a straight descriptive text of stones used in the building industry. Each type of stone discussed includes descriptions of the history of quarrying, historical impact, and even spectacular failures.

On the Downside - The addition of a few color illustrations could have been used to enhance the impact of Stories in Stone. Two photographs, one of them important to the storyline, were too dark to see the important detail as noted above.

Overall Rating - Despite the photographic issues I mentioned, I thoroughly enjoyed Stories in Stone. This is a great book for anyone interested in geology and the earth sciences.

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