- Usage in publication:
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- North Haven greenstone complex
- Modifications:
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- Named
- Dominant lithology:
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- Greenstone
- AAPG geologic province:
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- New England province
Summary:
Greenstone schists, mainly aphanitic and of light-yellow to grayish-green color on North Haven Island in Penobscot Bay, here referred to as North Haven greenstone complex. Includes diabases, also large masses of amygdaloidal greenstone and smaller amounts of a rather tuffaceous rock, at one point breccia-like. Locally the greenstone is quite plainly crystalline. The greenstone complex resolves itself into a series of diabase flows with accompanying pyroclastics. The age of these diabasic lavas is determined as pre-Niagaran [Middle Silurian], from their relations to the conglomerate at base of Niagaran sediments.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
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- North Haven greenstone*
- Modifications:
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- Revised
- Age modified
- AAPG geologic province:
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- New England province
Summary:
Name North Haven greenstone applied to rocks earlier described and mapped as North Haven greenstone complex. Unit is much older than the Silurian sediments and about contemporary with Islesboro and Castine formations. Assigned to Cambrian(?).
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
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- North Haven greenstone*
- Modifications:
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- Age modified
- AAPG geologic province:
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- New England province
Summary:
On 1933 geologic map of ME by A. Keith, this formation is included in block labeled "Mainly Silurian, but some of Devonian age."
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
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- North Haven Greenstone*
- Modifications:
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- Age modified
- AAPG geologic province:
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- New England province
Summary:
Age changed from Cambrian(?) to Middle Ordovician(?).
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
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- North Haven Formation
- Modifications:
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- Revised
- Age modified
- AAPG geologic province:
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- New England province
Summary:
Unit referred to as North Haven Formation rather than Greenstone. Age shown as Late Proterozoic.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
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- North Haven Formation
- Modifications:
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- Overview
- Age modified
- Revised
- AAPG geologic province:
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- New England province
Summary:
Unit has no firm age--"permissible ages range from Precambrian to Ordovician." Interpreted as earlier volcanic suite, possibly unrelated to Castine Formation, which it unconformably underlies. Contains abundant basalts and minor dacite, rhyolite and tephra. Crops out on Eagle, Fling, the Porcupines, and Hard Head Islands in southern ME.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
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- North Haven Greenstone*
- Modifications:
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- Age modified
- Overview
- AAPG geologic province:
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- New England province
Summary:
Late Proterozoic Islesboro Formation considered to be distal facies of North Haven Greenstone, Ellsworth Schist, and schist at Columbia Falls (eastern coastal ME). North Haven is predominantly pillowed and phyllitic greenstone (basalt and basaltic andesite) with minor silicic tuff, breccia, and pelite (Pinette and Osberg, 1989). North Haven unconformably underlies Silurian rocks containing Atlantic fauna. Age is changed to Late Proterozoic to Ordovician.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
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- North Haven Greenstone*
- Modifications:
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- Age modified
- AAPG geologic province:
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- New England province
Summary:
Age of North Haven Greenstone changed to Cambrian because it is thought to be equivalent along strike to Ellsworth Schist, dated as Cambrian by R.D. Tucker (1995, written commun.) who obtained a Pb-U zircon age of 509+/-2 Ma from tuff within Ellsworth.
Source: GNU records (USGS DDS-6; Reston GNULEX).
For more information, please contact Nancy Stamm, Geologic Names Committee Secretary.
Asterisk (*) indicates published by U.S. Geological Survey authors.
"No current usage" (†) implies that a name has been abandoned or has fallen into disuse. Former usage and, if known, replacement name given in parentheses ( ).
Slash (/) indicates name conflicts with nomenclatural guidelines (CSN, 1933; ACSN, 1961, 1970; NACSN, 1983, 2005, 2021). May be explained within brackets ([ ]).