Geology of the Hanover Quadrangle, New Hampshire-Vermont

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).…”

“…Typical exposures occur at Willard Ledge and on Prospect Hill in the Prospect Hill belt. The unit of Dl shown in the southeastern corner of the map in Corbin Park, east of the Northey Hill fault, was extrapolated from Lyons (1955) and from ongoing mapping in the adjacent Claremont North quadrangle…”

Summary results of the Glens Falls CUSMAP project, New York, Vermont, and New Hampshire

“…8). The Strafford dome to the south, on the other hand, is locally intruded by small dikes of granite pegmatite (Slack and others, 1987) and, like the Pomfret dome, coincides with a gravity low , suggesting granitic bodies at depth (see also Lyons, 1955). These relations permit the speculation that the emplacement of plutons in this area was accompanied by the introduction of metals, or the mobilization of preexisting metals, by hydrothermal processes active along zones of structural dilatancy(?…”

“…These concentrations of boron are possible indicators of ancient fumarolic centers, genetically linked to a submarine-exhalative environment (Slack, 1982;Taylor and Slack, 1984). Documented examples of such tourmalinites in the Glens Falls quadrangle occur at and near the Elizabeth mine in the Orange County copper district (Annis and others, 1983) and to the west of North Hartland, Vt., in the Hanover 15-min quadrangle (Lyons, 1955; J.F. Slack and M.P.…”