Relation to other divisions of the New England Uplands
There are two subsections of the New England Uplands in addition to the Reading Prong. A prong of the same rock belt extends from the Hudson Highlands south to New York City along the Hudson River. This region is often referred to as the Manhattan Prong. Staten Island Serpentinite is a southward extension of the New England Uplands.[2]
Geology
The Reading Prong is part of the Precambrian basement which is discontinuously exposed in the north-central Appalachians. The rocks that make up the prong consist of diverse gneisses.[3] The New England Province and the Blue Ridge province share many geological similarities, and some experts consider the Reading Prong merely a continuation of the Blue Ridge Mountains, which reach their northern terminus at South Mountain near Harrisburg, Pennsylvania.
In the gap between the Blue Ridge and the Reading Province, the two mountainous regions descend into the Appalachian Piedmont. Together, the Blue Ridge province and the New England province are often referred to as the Crystalline Appalachians. Rocks of the Reading Prong are characterized by elevated concentrations of uranium, the decay of which produces gaseous radon, a potentially hazardous source of indoor contamination in structures constructed on the prong.[4]