Geology of the Lebanon granite, Hanover, New Hampshire

Oliverian domes, related plutonic rocks, and mantling Ammonoosuc Volcanics of the Bronson Hill Anticlinorium, New England Appalachians

“…In this respect, it resembles the border gneiss of the Baker Pond pluton but differs from the Holts Ledge volcanic sequence of the Mascoma dome. No evidence was found for a proposed origin of the border gneiss by metasomatism of the adjacent Ammonoosuc Volcanics and the Partridge Formation (Kaiser, 1938).…”

Geochronology of the Oliverian Plutonic Suite and the Ammonoosuc Volcanics in the Bronson Hill arc: Western New Hampshire, USA

“…3). The granite has long been recognized as the plutonic core of the Lebanon pluton (Hitchcock, 1908;Merritt, 1921;Goldthwait, 1925;Kaiser, 1938;Lyons et al, 1997). The granite is in contact with the marginal quartz diorite (see below).…”

“…The quartz diorite is a gray, equigranular, moderately to well-foliated, medium-grained, blocky-weathering epidote-quartz-hornblende-biotite-plagioclase quartz diorite gneiss. The dated rock is a border phase to the core granite of the Lebanon dome pluton (Merritt, 1921;Kaiser, 1938;Lyons, 1955). The quartz diorite is in contact with graphitic schist of the Partridge Formation (Fig.…”

Bedrock geologic map of the Hartland and North Hartland quadrangles, Windsor County, Vermont, and Sullivan and Grafton Counties, New Hampshire

“…The quartz diorite is well exposed in Lebanon at an abandoned quarry about 450 m west of Slayton Road. This unit is the border-phase of the Lebanon pluton, and it surrounds a core of pink biotite granite, which is not exposed in the area of this map; the latter is exposed in the adjacent Hanover quadrangle to the north (Kaiser, 1938;Lyons, 1955). Valley and Walsh (2013) report a preliminary U-Pb SHRIMP zircon age of about 447 Ma for the quartz diorite.…”

“…The rock occurs discontinuously near the contact with the Lebanon quartz diorite. The metasomatized zone extends into the adjacent Hanover quadrangle (Kaiser, 1938;Lyons 1955); it was noted by Lyons but mapped differently Sulfidic schist member (Op)-Dark-gray to grayish-black, rustyweathering, sulfidic, graphite±garnet-plagioclase-biotite-quartzmuscovite phyllite and schist; locally contains light-to dark-gray micaceous quartzite in thinly laminated layers or boudins. In Plainfield, south of Town Farm Road, an anomalous micaceous quartzite contains accessory graphite, hematite, and garnet in the biotite zone (labeled "Grt" on map).…”