Part 1. Stratigraphy, structure and petrology of the Peterborough 1.5-minute quadrangle, New Hampshire and part 2. Graphite textural and isotropic variations in plutonic rocks, south-central New Hampshire
Abstract
The stratigraphy of the Merrimack Synclinorium in the Peterborough quadrangle is reinterpreted and correlated with fossil dated Silurian-Lower Devonian strata of western Maine. The earliest phase of the Acadian Orogeny produced west directed fold thrust nappes in this area. The Kinsman Quartz Monzonite was intruded along axial surfaces of these structures, locally establishing peak metamorphic conditions in the wall rocks. Intrusion of the Kinsman was closely followed by mafic intrusions of the Spaulding Quartz. Dorite possibly accompanying west northwest F sub 2 folding, and peak metamorphic conditions were reached in adjacent rocks. Graphite occurs in two distinct textural varieties in syntectonic granifolds of the New Hampshire Plutonic Series and in associated metasedimentary wall rocks. Textural characteristics indicate that coarse graphite flakes (0.1 to 1.0mm) were present at an early stage of crystallization of the igneous rocks and may represent xenocrystic material assimilated from the wall rocks.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1984
- Bibcode:
- 1984PhDT........14D
- Keywords:
-
- Petrology;
- Rocks;
- Stratigraphy;
- Folds (Geology);
- Geological Faults;
- New Hampshire;
- Textures;
- Geophysics