- Usage in publication:
-
- Wenham Monzonite
- Modifications:
-
- Age modified
- Geochronologic dating
- AAPG geologic province:
-
- New England province
Summary:
R.E. Zartman (1981, written commun.) obtained a Pb-U age of 395 +/-20 m.y. on zircon from Wenham Monzonite. Age is changed from Middle Devonian of Zartman (1977) to Early Devonian.
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
-
- Wenham Monzonite*
- Modifications:
-
- Overview
- AAPG geologic province:
-
- New England province
Summary:
Used as Wenham Monzonite of Middle Devonian age. [No explanation offered as to change in age from Early Devonian of Goldsmith and others (1982) to Middle Devonian in this report. Age remains Early Devonian according to GNC records.]
Source: GNU records (USGS DDS-6; Reston GNULEX).
- Usage in publication:
-
- Wenham Monzonite*
- Modifications:
-
- Overview
- AAPG geologic province:
-
- New England province
Summary:
Wenham Monzonite intrudes unnamed Proterozoic Z mafic volcanic-plutonic complex. Occurs over a 10 sq km area north of Peabody. Described as gray, weathering to cream, and medium grained. Distinguished from rocks of Cape Ann Complex by presence of plagioclase and biotite, and interstitial nature of quartz. Devonian age is based on Rb-Sr whole-rock date of 395 +/-20 Ma [reference cited is Zartman (1977), but Goldsmith and others (1982) state that this dates supersedes that of Zartman (1977)].
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 ([ ]).