(Map site 3.) Roadcut exposure of gneiss that has been intruded by a pegmatite dike. Within the pegmatite the pink mineral is orthoclase feldspar and the white areas contain quartz and other feldspar minerals. Pegmatites are the last rocks to cool from a molten intrusive mass and the crystals in a pegmatite are large (one inch or so) because they cool very slowly. After intrusion of the dike the whole rock mass was cut by a small fault that is clearly visible running from the upper left side of the photo diagonally down toward the feet of the observer on the road.
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