When geomorphologist Tom Meierding researches past environmental conditions and compares them with modern pollution levels, tombstones serve him better than test tubes or high-tech instruments.

One of fewer than a dozen researchers in the world who use gravestones as environmental guideposts, this UD geography professor has measured about 15,000 grave markers in more than 700 cemeteries during the last 25 years to study the environment, pollution and natural landforms.

During his research, he has visited small-town burial grounds and big-city memorial parks throughout the United States, including Hawaii, in addition to family and town plots in Canada.

The titles of a few of his journal articles highlight his areas of research: "Marble Weathering and Air Pollution in Philadelphia," Atmospheric Environment (1987); "Inscription Legibility Method for Estimating Rock Weathering Rates," Geomorphology (1993); "Marble Tombstone Weathering and Air Pollution in North America," Annals of the Association of American Geographers (1993); and "Philadelphia's Effect on Precipitation Acidity from Marble Gravestone Dissolution Rates," The Pennsylvania Geographer (2000).

In one of his articles, Meierding notes that "cemeteries have been among the most durable of cultural landscapes, preserved even in cities where competition for land is intense." And, while their longevity depends upon the condition of the monuments, these slabs of stone offer views into the culture, traditions, economies and priorities of the people of the region and time period.

What's more, Meierding says, insights into social patterns, artwork, architecture, heritage, religious influence and economic fluctuations--although not the primary focus of his research--also can be ascertained from the locations of cemeteries and the monuments that lie within them.

To gather the data for the bulk of his research, Meierding traveled across the United States for nearly two years, calculating the thickness of gravestones. In each graveyard, he took a scientific sampling of 30 stones, measuring the thickness of each at the base of the vertical marker and then making additional measurements higher up the slab.

Collecting dimensions from thousands of monuments meant that Meierding learned to practice serious time-management techniques. For example, whenever he drove his car into a small town for the first time, he immediately asked the locals for directions to the nearest church or town plot.

"I just went into a town blind and would ask older people in the streets," he says. "You don't go into a McDonald's and ask where the cemetery is."

After arriving at a location, he typically spent about two hours conducting his research and then drove 200 miles or so to the next site. He usually repeated this process three times each day. Often, the geographer slept in the back of his car beside a rural cemetery, rising in the morning to take his measurements and then set out on the road again.

Since he was concerned primarily with collecting data, Meierding says, he did not have the time to appreciate the unique art forms and cultural statements that many of these cemeteries offer.

"If I let myself begin to explore them," he says, "I would have never been able to finish the study."

Other graveyard investigation methodologies involve measuring the legibility of tombstone inscriptions (using similarly dated stones in different locales) and calculating and comparing the overall deterioration of tombstones in different regions.

Meierding says the fact that tombstones are dated is a significant factor and asset in his research. Side-by-side photographs of similarly dated marble slabs tell dramatically different stories, and it's fairly easy to apply a formula that determines the extent of damage on each stone, he says.

He has found that stones from the center of Philadelphia, Pittsburgh or Boston indicate serious deterioration, while stones located in rural areas of these same regions remain in a much higher state of preservation and legibility.

Meierding proposes that the effects of industrial pollution during the early, coal-burning years of the last century--when industrial plants were centered in the cities and environmental controls did not exist--were devastating to gravestones and even to the façades of buildings.

Although many people think that today's pollution and acid rain are the cause of this damage, Meierding says that is not the case, explaining that the worst effects of industrial sulfurous air pollution inflicted on weathered tombstones occurred 60-70 years ago. With much cleaner air--resulting from less manufacturing, the relocation of factories away from cities and tighter environmental laws enacted after World War II--the deterioration of historic and modern cemetery monuments has abated dramatically, he says. While there still will be natural effects from the weather and present-day pollution, he says, the rate of destruction has slowed appreciably.

Some of Meierding's research has been applied to projects related to historic preservation that he performs in conjunction with his adjunct position in the University's Department of Art Conservation.

"I'm not the first person to study tombstones to assess the weathering process," he says, mentioning a geologist in the 1880s who conducted studies in which gravestones were examined to determine how fast rocks decay.

Talk to Meierding and you'll learn a wealth of fascinating information. In New England, sandstone, slate and schist were the primary tombstone materials. Granite was prevalent in the 20th century, and marble--with its white character symbolizing purity and innocence--came into use during the Victorian era. Flat bronze markers are common today, and, at a few sites, grave markers made of aluminum and wood still can be found.

Students tend to find the research surprising, he adds, because they haven't spent much time in cemeteries.

"Most people who have been to one of my lectures, or have seen what I've done, will come back and tell me they've gone out and noticed something they hadn't seen before," he says.

Several of Meierding's undergraduate and graduate students have worked with him over the years and contributed their own research findings to some of his journal articles. He says all this work involving tombstones has implications well beyond determining past causes and future preservation techniques of centuries-old cemetery sculpture.

"We can extend the results of our research to other building and statuary materials," he says.

--Ed Okonowicz, AS '69, '84M