Massachusetts aerial survey underway for pyrrhotite, used in foundation causing crumbling concrete

AMHERST, Mass. (WWLP) – An ongoing geologic survey of the Connecticut River Valley is expected to shed light on pyrrhotite, the mineral implicated in weakening building foundations in southern New England.

Pyrrhotite, found in bedrock under certain parts of Connecticut and Massachusetts, can cause long-term structural weakness in construction when used in cement, causing building foundations to crumble.

22News has been covering the crumbling concrete issue that has been found in dozens of communities across western and central Massachusetts for many years. Thousands of homeowners could be at risk for pyrrhotite. The naturally occurring mineral causes concrete to slowly deteriorate as it’s exposed to oxygen and water.

“Increasing knowledge of New England’s geologic framework will help with national priorities, like earthquake and landslide hazards, water availability, and sourcing critical minerals — as well as regional concerns, like mapping pyrrhotite to minimize its use in local infrastructure,” said Jamey Jones, science coordinator for the USGS Earth Mapping Resources Initiative.

“I’m excited that this survey covers a large portion of southern New England. It will provide new insights into Connecticut’s bedrock that wouldn’t be possible without modern geophysical tools, and by coordinating with Massachusetts and Rhode Island, we can improve mapping along state borders. The results will help the Connecticut Geological Survey improve our understanding of geological hazards across the state,” said Meghan Seremet, Connecticut state geologist.

“Better geologic maps will help us screen for the presence of pyrrhotite, ultimately protecting homeowner investments. We have a broad sense of where this corrosive mineral is, but not enough detail yet to assure that it doesn’t end up in concrete that makes its way into people’s home foundations,” said Brian Yellen, director of the Massachusetts Geological Survey and professor at the University of Massachusetts—Amherst.

The survey is part of USGS’ Earth MRI, a partnership with the geological surveys of Connecticut, Massachusetts and other states, educational institutions and industry to modernize knowledge of the U.S. geologic framework.

Applications include mapping pyrrhotite and radon, assessing hazards such as earthquakes and landslides, and supporting efforts in mine waste remediation and resource recovery.

Instruments on an airplane will measure variations in the Earth’s magnetic field and natural, low-level radiation created by different rock types up to several miles below the surface. The information will help researchers develop geologic maps of resources and hazards in three dimensions.

Flights for the southern portion of the survey are based out of Robertson Airport in Plainville, Connecticut. The aircraft is equipped with an elongated “boom” that extends in front of the main cabin and houses sensors. These scientific instruments are completely passive with no emissions that pose a risk to humans, animals, or plant life.

No photography or video data is collected. With the survey underway, geologists hope to gain a better understanding of pyrrhotite distribution to prevent its use in construction materials, ultimately protecting homeowner investments in southern New England.

All facts in this report were gathered by journalists employed by WWLP. Artificial intelligence tools were used to reformat from a broadcast script into a news article for our website. This report was edited and fact-checked by WWLP staff before being published.