Government Pit (Government Gravel Pits), Albany, Carroll Co., New Hampshire, USA
|Latitude & Longitude (WGS84):||44° 0' 15'' North , 71° 9' 43'' West|
|Latitude & Longitude (decimal):||44.0041666667, -71.1619444444|
Granite pegmatite associated with the Conway granite. - The "gravel" is decomposed granite pegmatite from in-situ ledges. It is the "rotten stone" ledges which collectors have worked. (Note: This site is often erroneously cited as being in either Conway or North Conway.)
30 valid minerals. 1 erroneous literature entry.
Rock Types RecordedEntries shown in red are rocks recorded for this region.
This information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This data will improve over time as more accurate maps and data sets are added.
|Late Jurassic - Middle Jurassic145 - 174.1 Ma||Conway Granite|
Part of the White Mountain igneous province of McHone and Butler (1984) - Overall part of the White Mountain Plutonic-Volcanic Suite - Includes Cretaceous alkalic syenite to granitic to gabbroic plutons, minor volcanic rocks, and lamprophyre dikes of the New England-Quebec igneous province of McHone and Butler (1984); also includes Jurassic granite and syenite and less abundant quartz syenite, diorite, gabbro, nepheline syenite, and volcanic rocks of the White Mountain igneous province of McHone and Butler (1984). Middle - Late? Jurassic White Mountain Plutonic-Volcanic Suite: Gore Mountain granitic intrusive rocks = 169+/-3 K/Ar per NH013. Percy pluton = 166+/-4 K/Ar per NH013. Pliny Range intrusive rocks = 182+/-4 and 189+/-5 K/Ar per NH013; also 183+/-2 Ar/Ar per NH019. Cannon Mountain pluton = 184+/-4 K/Ar per NH022 and 194+/-4 K/Ar per NH013. Conway Granite = 183+/-5, 182+/-4, 180+/-4, 178+/-4, 171+/-4, and 155+/-4 K/Ar per NH023. Mad River pluton = 178+/-5 K/Ar, 158+/-4 Rb/Sr, biotite, per NH022. Belknap intrusive rocks = 159+/-3 K/Ar per NH022. 161+/-5 Rb/Sr and 158+/-3 K/Ar, biotite, per NH013. 169.3+/-1.7 Rb/Sr per NH033.
|Permian - Carboniferous252.17 - 358.9 Ma||Carboniferous-Permian plutonic rocks|
Deep-seated to high-level intrusions are included. Many charnockites, anorthosites, and large ophiolites, classified as plutons, are distinguished in the database using the SIGNIF item. Ophiolites were classified as plutons, even where remnants may be extrusive and/or sedimentary.
|Pennsylvanian - Mississippian298.9 - 358.9 Ma||Mississippian-Pennsylvanian plutonic: undivided granitic rocks|
Plutonic: undivided granitic rocks
References for regional geology:
Data provided by Macrostrat.org
Garrity, C.P., and Soller, D.R.,. Database of the Geologic Map of North America: adapted from the map by J.C. Reed, Jr. and others (2005). U.S. Geological Survey Data Series 424 .
USGS compilers. State geologic map data. State Maps.
Geological Survey of Canada. Generalized geological map of the world and linked databases. doi:10.4095/195142. Open File 2915d.
Bearss, Gene and Janules, Bob (1992): Miarolitic Cavity Minerals of the Govemment Pit, Albany, New Hampshire (Rocks & Minerals 67:158-169).
Camp, Kristen F. (2011), "Mineralogy and Geochemistry of Anorogenic Granitic Miarolitic Pegmatites Associated with the White Mountain Intrusive Suite, New Hampshire." University of New Orleans Theses and Dissertations. Paper 1363.