The origin and structural relationships of leucogranitic gneiss bodies in the Adirondack Lowlands represnnt controversial problems in the Adirondacks. Most of the early published work, as later summarized by Buddington (1939) suggested that these bodies were unconnected intrusive igneous bodies later affected by penetrative deformation and metamorphism. Granitic magma was intruded into the axial zones of major folds to form lens-shaped, concordant masses that he labeled “phacoliths.”
A subsequent idea, credited to Bloomer by Engel and Engel (1963), suggested a metasedimentary origin for these bodies. In this model, the granitic masses represent metamorphosed, transformed, layered rocks occupying specific stratigraphic positions in the Adirondack Lowlands. Wynne-Edwards (1967), Lewis (1969), and Carl and Van Diver (1971, 1975) shared this opinion, Foose and Carl (1977) proposed an integrating model to explain the structural setting of the “alaskite” bodies of the Adirondacks Lowlands as parts of a single, extensive, folded sheet.