Stories in Stone

by David B. Williams

  Folk questioned the biologists’ hypothesis particularly after seeing an SEM photo from Bulicame in April 1990. The eureka photo is mostly gray with a white plane, the top part of the crystal, running from the upper left corner to the bottom right corner. Below the plane is a light gray surface dotted with many spheres and one white, sausage-shaped body. On the left side of the plane rests an ovoid body, which looks large enough to encompass most of the other spheres. The ovoid is about twice as tall as the most unusual shape in the photo—a thin, saguaro-cactus-like body that rises from the center of the plane and which Folk described as a chain of eight nannobacteria. The entire shot shows an area 3.5 microns wide by 2.5 microns high, less than half the size of a red blood cell.

  To Folk, these odd little balls and chains closely resembled bacteria shapes, and didn’t look like any minerals he had seen in his decades of peering through microscopes. Unlike minerals, which tend to grow together as one mineral and not remain as single entities, they also clustered in swarms like bacteria in a “feeding frenzy.” The more Folk peered at these unusual objects, the more he became convinced he was seeing life and neither artifacts nor minerals. He published his results in 1993 in another landmark paper, SEM Imaging of Bacteria and Nannobacteria in Carbonate Sediments and Rocks.11 This was the well-illustrated paper that Romanek and crew poured over in trying to understand Martian meteorite ALH84001.

  Once he found nannobacteria in his travertine, Folk began to find them everywhere. They were in cold freshwater spring deposits, deep underground in caves, in shallow saltwater, and in two-billion-year-old dolomite. Nannobacteria-generated calcite clogged a pipe from a hot water heater and scummed a birdbath. Nannobacteria balls covered corroded iron, copper, aluminum, and lead. Noncarbonate rocks, such as opal, chalcedony, and chert, also showed a nannobacterial origin. Unknown to Folk, others had begun to see nannobacteria, too.

  Folk was working in his lab on August 7, 1996, when a colleague rushed in and said “Have you heard the NASA TV conference? They found nannobacteria in the Martian meteorite.” What Folk’s colleague didn’t tell him was that in describing their nannobacteria, the NASA team had used a slide showing the nannobacteria Folk had described from travertine at Bulicame. “Yes, I was excited, but when their results first came out in the press as photos, my colleague Leo Lynch and I both thought the same thing. Gee, their pics look like excess gold coating artifacts,” said Folk. “Later when they used a thirty-second gold coat, we were convinced that they did indeed have nannobugs.” When Folk was able to look at ALH84001 under a SEM he found it permeated with nannobacteria.

  Not everyone agrees that the Martian meteorite teems with supermicroscopic life. One scientist I corresponded with e-mailed me: “The existence of nannobacteria in extraterrestrial rocks (or any other life form, for that matter) is completely UNPROVEN, in my opinion (an opinion that I think you’ll find to be almost universally shared).” The skeptics’ main concern is that classic line “size matters.”

  Nannobacteria are too small to contain all of the nucleic acids and ribosomes necessary for life. This was the conclusion reached by a distinguished panel of scientists in a National Academy of Sciences workshop in October 1998. Inspired by NASA’s report of Martian life, the panel sought to establish the smallest size of a free-living organism. The consensus was that between two hundred and three hundred nanometers “constitutes a reasonable lower size limit for life as we know it.” Folk’s smallest nannobacteria are only fifty nanometers wide.

  Despite the establishment of this Maginot Line on the minimum size of life, researchers continue to report that they have found and cultured, or reproduced, nannobacteria-like bodies. The hottest field at present is in medicine, where researchers have reported nanoparticles in human, rabbit, and bovine blood. As occurs in travertine, the nanoparticles appear to generate calcite that contributes to health problems as diverse as kidney stones, malignant tumors,Alzheimer’s disease, and heart disease.

  “At this point we cannot be sure if the nanoparticles are living or not. Part of the problem is that we haven’t perfected how to investigate them,” said Virginia Miller, a professor of physiology at the Mayo Clinic.12 In 2004 she was lead author on a paper that examined the role of nanoparticles and atherosclerosis, and in 2006 she co-organized a conference on pathological calcification, which brought together experts in biology, geology, and medicine.

  Although Miller still wavers on whether nanoparticles are living organisms or not, she, like everyone else I talked with, credited Folk with stimulating her research. “I think we are at the forefront of something exciting. I will accept whatever we find but either way Dr. Folk’s work has really given us a new way to think about the disease process, at least in regard to kidney stones and arterial calcification.”

  Miller’s comments get to the heart of Robert Folk’s research with travertine, bacteria, and nannobacteria. Ultimately, it isn’t critical whether the nanometer-sized particles he sees are living or not. What is important is the scientific process. He saw something, travertine in Bernini’s columns at St. Peters, that intrigued him. He studied it and published his results, which raised awareness in others and more questions in him. He went back out in the field, collected more samples, and took advantage of technological advances to ferret out additional answers. He also was persistent, spending hours and hours learning to use the new technology. Again he reported what he had found, and he continued to try to better understand and learn about what he had discovered.

  No place better exemplifies the use of travertine as a building stone in the United States than the Getty Center in Los Angeles. Designed by Richard Meier and built between 1984 and 1997, the Getty incorporates 290,000 travertine panels to cover the multibuilding complex of museum galleries, restaurant and café, auditorium, research institute, and conservation institute. All of the stone came from the deposits at Bagni di Tivoli.13 The roughly one million square feet of travertine ranges from 71.2-by-71.2-inch paving blocks to fifty-by-ninety-inch picture, or feature, stones, as architect Richard Meier termed the largest panels. He scattered them throughout the complex, often at eye level, in order to “provide a heightened awareness of the material.”14

  The Getty sits on a high ridge just west of Interstate 405 as it heads north from Westwood and up to Sepulveda Pass. Parking is underground in the multilevel garage. A travertine-floored elevator carries you up to the tram station and platforms of travertine. Since visitors cannot drive up to the Getty Center, most everyone parks in the garage and takes the 41.2-minute ride on an electric tram up the hill.

  Meier has described the tram ride as elevating visitors “out of their day-to-day experience” and “at the same time, they’ll have a powerful sense of being in the center of this great city.”15 Perhaps he meant that being stuck in a vehicle with a top speed of ten miles per hour would give you that true, L. A.-traffic-jam feeling.

  The tram rolls quietly for three-quarters of a mile through the chaparral vegetation of the Santa Monica foothills to the summit, 881 feet above the Pacific Ocean. Detramming occurs in the arrival plaza, a flat, open square with three pines and a large sculpture, titled “That Profile.” Map-wielding docents meet the trams. They may also offer umbrellas, not for rain, but for sun. In the summer, umbrellas must be essential, as the sun blasts and bakes the travertine.

  The plaza is the first introduction to travertine in all its splendor. The walls are unlike any other travertine building stones in the country. Most of the thirty-by-thirty-inch blocks have a rough surface and look like sepia-tone aerial photos of the desert southwest with miniature mesas, plateaus, valleys, and ridges. Although most of the blocks are the color of lightly toasted sourdough bread, some have highlights ranging from brownish orange to black, which enhance the three-dimensionality of the panels. The color results from oxidized iron.

  The Getty Center, Los Angeles.

  Because Meier associated the normal cut of travertine—which sliced the stone perpendicular to the bedding�
�with building lobbies, he wanted a different look for his stone. He achieved it by cutting the Getty’s travertine along the bedding planes, akin to opening a deck of cards and seeing the faces. “We wanted the stone to look like stone when viewed from the freeway,” said Michael Palladino, who ran Meier’s Los Angeles office during the construction of the Getty.16 “Up close typical travertine looks nice, but from a distance it looks like wallpaper.”

  “The process was fairly simple. We would cut thirty-inch by thirty-inch by eight-foot-long sausages and shove them through the guillotine. The blade would fall and break the stone along its weakest point. We never knew exactly where it would split,” said Palladino. The initial piece would be eight to ten inches thick, too thick to hang as veneer, so it would be cut down to thinner slices forming two façade stones and two to four pavers. “We were pretty proud of ourselves for figuring out how to cut the stone into so many pieces, but we were still way over budget,” he said. Despite such cost-cutting measures the total cost of the Getty complex ended up being $1 billion.

  Meier didn’t originally plan on using travertine. He is best known for his metal panels, always white, which he has described as the “most wonderful color because within it you can see all the colors of the rainbow.”17 The Getty’s neighbors, including the powerful Brentwood Homeowners Association, however, didn’t buy such a flowery description of white. For six years, they wrestled with the Getty over the project. In the end, the two sides agreed to a building permit with 107 conditions, one of which banned Meier from working in white. Other requirements mandated a sixty-five-foot height restriction for buildings and that dirt could neither leave nor get shipped to the site. Meier described the neighbors’ attitude as “we don’t want to see you, we don’t want to hear you, and we don’t want to smell you.”18

  “The landscape also dictated that we use stone,” said Palladino. “It is raw and rugged. We could either chop the hills and drop them flat or leave the topography and use this architectural element to connect the buildings to the land.” If they had used metal, he added, it would have given the buildings a more pristine look and created an object quality; the buildings would appear to have settled into the landscape. “Stone, in contrast, would give a sense of the buildings rising from the land,” he said. “We also wanted to give the Getty a sense of history and stability. We wanted to ground the institution, even though it was a young organization.”

  Palladino’s observations are a bit ironic. In order to build the museum, the Getty shipped a hundred boatloads of travertine across the Atlantic Ocean, through the Panama Canal, and up the Pacific Ocean to Los Angeles. How strong is the connection to landscape, considering that the central grounding force, the travertine, had to travel halfway around the world to connect the museum’s structures to place? I don’t mean to single out the Getty for what they did; builders and architects have been shipping stone willynilly around the world for centuries. Such trade will not stop, and even seems to be increasing with new stones from exotic locales appearing every day, but transporting building stones has an environmental impact that builders and architects should consider.

  To start the process of finding the right stone, Palladino sent notes out to stone suppliers asking them to send panels to the Meier office near UCLA. “This generated a whole lot of interest,” he said. They literally had to rent a warehouse to store the hundreds and hundreds of samples. He and Meier eliminated 75 percent of the stone based on color, realizing after a more careful study and exploration of the site that they wanted a stone similar to the natural buff-colored rock on the building site.

  Several stones stood out but were eliminated because they were too expensive or the quarry couldn’t provide the quantity or provide it fast enough. “One quarry was excavating by hand. They couldn’t have gotten enough rock to us in a hundred years,” said Palladino.

  They finally chose the travertine, in part because of the persuasiveness of Carlo Mariotti, the late father of the present owners of the Tivoli quarry. On a visit to Rome, Palladino and Meier had noticed rough-cut, nonbedded travertine used as decorative elements in buildings. They realized that this was the texture they were looking for, but no one had ever used this cut of travertine for a façade, particularly for a large project like the Getty. Mariotti convinced them he could cut the stone to show the rough surfaces. It took a year to develop the giant cleaver, dubbed Big Bertha, to cut the vertical slabs.

  Carlo Mariotti was also the man responsible for supplying stone for many of the travertine buildings in the United States.19 In 1958 he provided the stone for Ludwig Mies van der Rohe’s Seagram Building. Although Mies used travertine only in the plaza and entryway, it provided a classic contrast to the modernism of the glass tower. More fame for travertine came between 1962 and 1968, when architects such as Philip Johnson and Eero Saarinen clad Lincoln Center for Performing Arts in travertine from Mariotti’s quarries.

  Most major cities in the United States contain at least one building dressed in travertine. Architects often use travertine as van der Rohe did, in foyers, as flooring and accents, the Sears Tower in Chicago and the former World Trade Towers being good examples. (The Towers’ architect, Minoru Yamasaki, who coincidentally went to the same high school in Seattle as I did, had a close friendship with Carlos Mariotti and used his travertine in buildings in Japan, Boston, and Seattle.) The first travertine most people encounter in Los Angeles is on the walls and floors of LAX airport.

  The Mariotti quarry and factory still use Big Bertha and its accompanying machinery. American architects, however, do not employ the cleft stone. “Big-name American architects won’t work with it because they consider it to be ‘Meier’s stone.’ Architects from other countries, however, don’t have the ego problem and we sell a lot of it to builders in the Middle East,” said Fabrizio Mariotti, who along with his brother Primo now runs the family business.20

  As you wander the Getty and walk up to any wall of travertine, you will probably find fossil leaves in the cleft stone. They look like poplar, ivy, and dogwood and are so detailed and well preserved you can pick out individual veins and stems and tell if the leaf was upside down or right side up when it fossilized. A few even appear to have been torn or partially eaten, perhaps by leaf miner insects, prior to fossilization. The leaves look as if you can simply peel them off the wall.

  The fossiliferous panels are ubiquitous: Meier thoughtfully placed many of the best in popular locations or in places such as along stairs where you have to move slowly. Some slabs have only a few leaves, but many have leaves piled atop each other. On the leaf-rich panels, the leaves face in all directions, just what to expect of leaves that fell in a shallow lake and collected together in the ooze on the bottom. Fabrizio referred to this phenomenon as seeing “autumn 20,000 years ago.”21 The autumnal feeling is enhanced where beautiful bronze and brown California live oak leaves have dropped next to the fossil leaves.

  Not all of the travertine is sourdough colored. In the main entry to the museum buildings, Meier chose a chocolaty travertine to provide a contrast between the exterior and interior. A couple of panels, particularly ones near the bathrooms, feature an unusual set of fossils. One looks like a mini–Milky Way Galaxy, another like a tiny spaceship, complete with thrusters, and a third resembles a snail. Less than one-half inch wide, the white to tan fossils had been snails, most likely land-based species that had fallen into the water.

  Close-up of leaf fossil at the Getty Center, Los Angeles.

  The most amazing panel at the Getty and the coolest part of the entire complex is one of Meier’s feature stones. It is on the backside of a wall in the arrival plaza, directly opposite the tram station. The ninety-by-fifty-inch panel juts out ten inches from the surrounding panels and is the most stunning panel of building stone I have seen anywhere.

  The giant slab of travertine looks like a jumbled mix of straws, melted wax paper, and spaghetti except that the straws are fossilized reeds, the waxy sheets are fossilized rafts of bacteria
, and the spaghetti strands are fossilized mosses and algae. White to translucent calcite has filled in some reed tubes either completely or enough to leave only a small hole in the center. Most are hollow, though, and wide enough to stick a pencil into. The fibrous moss and algal strands cross and crisscross like a spiderweb.

  As with the leaf panels, there is a distinct feeling of water; you can envision a quiet swamp with reeds pushing up through a surface coating of bacteria and moss. Some of the reeds stand upright. Others tilt and overlap. Perhaps birds or insects alit on the hollow green stems, seeking a meal of the invertebrates that lived on the mosses. (Coincidentally, on either side of the wetland panel are two much smaller panels, each with a fossil of a ten-inch-long feather.) You can almost hear the calling of frogs and smell the pungent decay of vegetation. The large brown panel is exquisite, life in a wetland caught in the act of fossilization.

  Another texture at the Getty seems almost too ephemeral to have become rock. The surface of many blocks is honeycombed with one-eighth-inch-wide circles, but bees didn’t produce the pockets. Instead the texture resulted from solidified gas bubbles, basically solid foam. As the bubbles floated through the water, calcite coated the surface and froze the diaphanous effervescence as a permanent feature. Because of the way the guillotine split the travertine, it chopped open the gas bubbles.

  Calcite can also accumulate on the surface of ponds, building up playing-card-thin gossamer rafts. As happens with the bubbles, rafts can be blown across a pond and collect in thick layers, which in stone look like strewn sheets of phyllo dough. The raft-rich panels are widespread at the Getty and many also feature fossilized stems of green algae that resemble very thin, salt-coated pretzel sticks.