Geochronologic studies in central New England I: Evidence for pre-Acadian metamorphism in eastern Vermont

Journal Article · Wed Feb 01 04:00:00 EST 1989 · Geology; (USA)

DOI:https://doi.org/10.1130/0091-7613(1989)017<0181:GSICNE>2.3.CO;2· OSTI ID:7242879

Spear, F S ^[1]; Harrison, T M ^[2]

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1. Rensselaer Polytechnic Institute, Troy, NY (USA)
2. State Univ. of New York, Albany (USA)

{sup 40}Ar/{sup 39}Ar geochronology on hornblendes from central New England reveals a Grenvillian cooling age (1026 {plus minus} 12 Ma) along the eastern margin of the Green Mountain massif, Acadian ages in east-central Vermont (350-397 Ma) and along the Bronson Hill anticlinorium in New Hampshire and Massachusetts (407-280 Ma), and Late Ordovician to Silurian ages (440-451 Ma) along a belt in eastern Vermont and central Massachusetts. These ages indicate a minimal Acadian overprint in eastern Vermont, the highest degree of Acadian overprint being located along the axis of the domes in the Connecticut Valley synclinorium. These data suggest that the formation of the domes occurred in the Acadian. Moreover, the Late Ordovician to Silurian cooling ages in eastern Vermont suggest that much of the metamorphic mineralogy and fabric observed in the Connecticut Valley synclinorium may be pre-Silurian in age.

• OSTI ID: 7242879
• Journal Information: Geology; (USA), Journal Name: Geology; (USA) Vol. 17:2; ISSN GLGYB; ISSN 0091-7613
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
580000* -- Geosciences
AGE ESTIMATION
AMPHIBOLE
ARGON 39
ARGON 40
ARGON ISOTOPES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
COOLING
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FEDERAL REGION I
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC HISTORY
HORNBLENDE
ISOTOPE DATING
ISOTOPE RATIO
ISOTOPES
LIGHT NUCLEI
MASSACHUSETTS
METAMORPHISM
MINERALOGY
MINERALS
NORTH AMERICA
NUCLEI
ORDOVICIAN PERIOD
PALEOZOIC ERA
RADIOISOTOPES
SILICATE MINERALS
STABLE ISOTOPES
USA
VERMONT
YEARS LIVING RADIOISOTOPES