Mineral Resources On-Line Spatial Data
Mineral Resources > Online Spatial Data > Geology > by state > Vermont
|Original map label||Oal|
|Comments||Part of Eastern Vermont Secondary unit description per VT011: Mapping done from 1983 to 1992 indicates that rocks mapped as Albee by Billings (1956) in NH and by Doll and others (1961) in VT can be divided into two assemblages. One includes metamorphosed volcanic and volcaniclastic rocks of the strike belt that extends across the type area of Albee. Although Moench (1984) tentatively correlated this assemblage with Cambrian(?) Jim Pond and Hurricane Mountain Formations, felsic metavolcanic and hypabyssal intrusive rocks of the assemblage subsequently yielded Silurian U-Pb zircon ages. Furthermore, assemblage was found to be divisible into six Ordovician, Silurian, and Silurian(?) formations (listed above). Also, Foster Hill fault separates this assemblage of allochthonous formations from autochthonous sequence that contains Ammonoosuc Volcanics. It was found, therefore, that type Albee does not lie stratigraphically below type Ammonoosuc and that all rocks exposed within type area of Albee could be assigned to other formations. The second assemblage composed of quartzite and metashale actually lies below the Ammonoosuc Volcanics and Partridge Formation and conforms more closely to original Albee definition; however, rocks represented by this second assemblage are not present in Albee type area. They are widely exposed astride the NH-ME border and are coextensive with and identical to the Upper Cambrian(?) and Ordovician (lower part) Dead River Formation of Osberg and others (1985), who reassigned rocks originally mapped as Albee in westernmost ME to the Dead River. Because of precedence set by Osberg and others (1985), and because type area of Albee is no longer viable, Dead River Formation is here applied to rocks of quartz-metashale assemblage in NH known to lie stratigraphically below Ammonoosuc Volcanics or Partridge Formation (Moench, and others, 1995).|
|Primary rock type||quartzite|
|Secondary rock type||slate|
|Other rock types||phyllite; mica schist; hornfels; tuff|
Metamorphic > Metasedimentary > Metaclastic > Quartzitemassive, gray, white-weathered quartzite and feldspathic quartzite; micaceous quartzite
Metamorphic > Metasedimentary > Metaclastic > Phyllitefeldspthic phyllite and quartzose argillaceous phyllite
Metamorphic > Metasedimentary > Metaclastic > Slate
Metamorphic > Schistquartz-mica schist, mica schist
Igneous > Volcanic > Felsic-volcanic > Rhyolite (Pyroclastic, tuff)Soda-rhyolite tuff occurs locally.
Metamorphic > Hornfelshornfels contining porphyroblasts of biotite, garnet, staurolite and sillimanite in the vicinity of granitic plutons
Nicholson, S.W., Dicken, C.L., Horton, J.D., Foose, M.P., Mueller, J.A.L., and Hon, Rudi, 2006, Preliminary integrated geologic map databases for the United States: Connecticut, Maine, Massachusetts, New Hampshire, New Jersey, Rhode Island, and Vermont: U.S. Geological Survey Open-File Report 2006-1272.
Doll, C.G., Cady, W.M., Thompson, J.B., Jr., and Billings, M.P., 1961, Centennial Geologic Map of Vermont: Vermont Geological Survey, Miscellaneous Map MISCMAP-01, scale 1:250,000.
|Geographic coverage||Caledonia - Essex - Orange|
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