Conway granite near where it is mined. The Old Man of the Mountain, a famous geologic feature in New Hampshire (which collapsed in 2003) was made of Conway granite. The formation is found throughout the lower areas of the central White Mountains, such as Franconia Notch, Crawford Notch, the center of the Pemigewasset Wilderness, and the Saco River valley. Other exposures of the formation include the Belknap Mountains south of Lake Winnipesaukee. Conway granite Conway granite is a typically pink mineral-rich igneous (or mesoperthitic) biotite granite. It is amphibole-free and of coarse particle size (with portions of the rock fine-grained or porphyritic).
Dedham Granite Dedham Granite Dedham Granite is a light grayish-pink to greenish-gray, equigranular to slightly porphyritic, variably altered, granite south and west of Boston, named for the town of Dedham, Massachusetts. Dedham Granite includes dioritic rock near Scituate and Cohasset and Barefoot Hills Quartz Monzonite. Intrudes Zdi, Zgb, Zb, Zv. Extensive calc-alkaline plutons separated by Boston basin have long been mapped as Dedham. Those to the north of Boston and studied by the US Geological Survey, are referred to as Dedham North. Crystallization ages for the Dedham North suite (based on titanites and zircons) have been determined at 607+/-4 Ma, while ages