The Matagamon Sandstone - a new Devonian formation in north-central Maine

The Matagamon Sandstone is a thick clastic unit of Becraft and Oriskany (Early Devonian) age in northern Penobscot County, Maine. The type section is on Hay Mountain, east of Grand Lake Matagamon from which the sandstone takes its name. Thick-bedded rusty-weathering sandstone constitutes about 80 percent of the unit. Dark slate and siltstone make up the remainder. The Matagamon is at least 4,000 feet thick and is interpreted to be a sandstone lens equivalent to the upper part of the slaty Seboomook Formation.