This story was originally produced by the Concord Monitor. NHPR is republishing it in partnership with the Granite State News Collaborative.
A new report from the U.S. Geological Survey is touting the possibility that the region might hold big deposits of the valuable metal lithium, which will come as something of a surprise to New Hampshire, even if it is old hat in Maine.
“The Plumbego North deposit in Newry, Maine, been studied for several years, with very detailed mapping and resource assessment,” said Matt Davis, associate professor of Earth Sciences at UNH. That site is considered one of the best hard-rock lithium deposits on the continent and Maine has seen considerable debate about whether to try mining it.
The report from the USGS released Wednesday might lead to similar discussions in New Hampshire.
“The report says … that we see it (lithium deposits) in Maine and the geological conditions suggest that similar deposits likely exist in New Hampshire,” said Davis. “It’s really looking at undiscovered deposits, the possibility of large lithium ore deposits that have yet to be discovered, using geological maps, geochemical data, and other (factors).”
The report doesn’t pinpoint likely locations for new mines.
“It indicated areas where conditions are favorable, but didn’t say, here’s where they’re going to be. I think the goal is to identify the potential for the resource, to warrant additional investigations if there is interest in the market, in terms of policy. I think it helps to start that conversation,” Davis said.
Lithium has long been a valuable resource for industrial and health-related applications, but has become much more important as the energy transition has increased the importance of batteries, often based on various lithium chemistries. About half of the lithium used in the U.S. is currently imported.
The USGS says the Appalachian region from Maine to George has enough lithium that can be economically mined to replace 328 years of U.S. imports.
Lithium is often found in pegmatites, a term for coarse igneous rocks formed when hot magma cools. A common source of pegmatites is granite, so there’s no reason lithium deposits shouldn’t exist in the Granite State, even through there is no history of lithium mining here. The closest we come is mining for mica, which is also found in pegmatites, with Ruggles Mine in Grafton the best-known example.
“There are some mines in NH that we know that these (lithium) resources exist, but I’m not aware of anyone who has really gone in to try to quantify the amount,” said Davis.
Lithium-rich pegmatites in the northern Appalachians were formed more than 250 million years ago when plate tectonics forced Africa, Europe, and North America together into a supercontinent named Pangea. “Pegmatites like the ones found in the Appalachian mountain belt are found in corresponding areas of Ireland and Portugal, both of which formerly bordered the Appalachians,” USGS noted.
The only commercial use of lithium in New Hampshire was a long-forgotten health tonic called Londonderry Lithia, which was naturally infused with the substance. The company thrived as part of a short-lived health fad for “lithia water,” but collapsed in the 1920s following revelations that any benefits were exaggerated.
