ALLEN, Timothy T., Geology Dept., MS 2001, Keene State College, Keene, NH 03435-2001, tallen@keene.edu
The Gorham, NH-ME, Quadrangle was first mapped by M.P. Billings and K. Fowler-Billings primarily during the period 1951-1953, with their report published in 1975--one of the last maps they published. Problems confronted in this area included the determination of stratigraphy and large-scale structure within migmatitic gneisses, and the relationships between tectonics, plutonism and regional metamorphism. They determined that an understanding of the map pattern remains essential to the interpretation of structurally complex areas. Subsequently, rocks exposed in the southern half of the Gorham quadrangle have been key in correlating rocks from central New Hampshire to an established stratigraphic sequence in western Maine, and in furthering understandings of migmatization processes. Reinterpretation of the stratigraphy of the migmatites, together with field relationships and structural studies, has suggested a relationship between structural development and magmatism along the axis of the Acadian orogeny.
tectonics, plutonism, metamorphism, Acadian orogeny
1998 Geological Society of America Abstracts with Programs vol. 30, no. 1, p. 1