A UMass Boston researcher combines geology with archaeology to see what lies beneath Beantown.
Jennifer Weeks
Geologists and archaeologists both do a lot of digging, but the overlap might appear to stop there. Archaeologists focus on human history while geologists look back across millennia to study the impact of processes like glaciation and plate tectonics.
Allen Gontz, assistant professor of coastal geography and geophysics at UMass Boston, brings these two disciplines together. Gontz has worked with Boston’s preservation community for the past several years using geological tools to find, analyze, and conserve historic landmarks. “Traditional archaeology digs up remnants of society to see how people lived,” says Gontz. “Geology adds information about the landscape that they occupied, the climate, and how people interacted with the setting.”
For example, Gontz is working with the Paul Revere Memorial Association to locate old foundations at the Paul Revere House in Boston’s North End, using high-resolution ground-penetrating radar. Data are still coming in, but he expects to produce some findings later this spring that may show how the site has evolved over time.
Paul Revere’s house in Boston’s North End. (Source: Wikipedia_House)
“Curators have records of how the property changed hands and what existed around it, but they aren’t really sure exactly where those things were located,” Gontz says. “When the building burned down, did they salvage the foundation blocks for another house? Where are the privies and wells?”
If the team is able to locate the foundations, preservation groups can restore the property to the way it looked in the 1700s, when Revere began delivering messages for the American revolutionaries, Gontz says.
Geologist’s toolbox
Much of Gontz’s research looks at how coasts have changed due to forces such as erosion, glaciation, sea-level change, and human development since the peak of the last ice age, about 23,000 years ago. He and other UMass researchers contributed to a report published last year, which projected that rising sea levels due to global climate change could permanently flood parts of Cape Cod and Long Island, and most of New Jersey’s coastline.
Gontz measures coastal change using tools that include sidescan sonar (which emits fan-shaped pulses across wide swaths of the sea bottom), magnetometers, and sub-bottom profilers that map sediment layers using sound waves. He also uses some of these tools for his historic preservation projects.
Gontz directs UMass’s GeoSTRAT Lab, which brings together geological and archaeological methods to study how physical and sociological environments have evolved over time. The lab’s partners include the Massachusetts Board of Underwater Archaeological Resources (BUAR), which is part of the state’s coastal-zone management office, and Boston’s city archaeologist, who oversees the archaeological remains on Boston public land.
Underwater and underground
Among the lab’s recent projects are 2006 sonar surveys of the ocean floor in Boston Harbor for two proposed shipwreck sites: the French man-of-war Magnifique, which sank off Lovell’s Island in 1782, and the USS Niagara, a Civil War blockade-runner scuttled in the harbor in 1897.
“It’s a real collaboration,” says BUAR director Victor Mastone. “Archaeologists tend to do everything on a shoestring, but Allen collects data on a much bigger scale, so he’s always pushing us to do more.”
The team found promising targets but did not pinpoint either wreck. Still, Gontz says hunting for shipwrecks is useful for coastal studies. “If you know when and where a ship went down, you can look at erosion, deposition, and sediment transport in that tiny landscape,” he says.
Gontz is also working with Boston’s city archaeologist and the Dorchester Historical Society at Blake House, which dates back to about 1648 and is Boston’s oldest house. The building was moved from its original location to what was formerly known as Dorchester Commons in 1895. “We’re trying to determine what the commons may have looked like before they moved the house there,” he says. The team is excavating a filled-in pond and examining pollen and plant fossils to paint a picture of the landscape in the late 19th century. Geological excavation at the site will continue through this summer.