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).
A-type granite A-type granite A-type granites are a class of granite. They are characterised by low water and a lack of tectonic fabric. A stands for anorogenic or anhydrous. The granite class was proposed by Loiselle and Wones in 1979. It was in addition to I-, S- and M-type granites. The A-type granites form in an extensional tectonic setting. This could either be far from any orogeny, or after orogeny is completed. Chemical characteristics of A-type granites include high silica, alkalis, zirconium, niobium, gallium, yttrium and cerium. The ratio of gallium to aluminium is high, as is the ratio of iron to