Late proterozoic-early Paleozoic crust in the Hermitage flexure, Newfoundland Appalachians: U/Pb ages and tectonic significance
Journal Article
·
· Geology; (USA)
- Royal Ontario Museum, Toronto (Canada)
- Newfoundland Department of Mines, St. John's (Canada)
Fault-bounded amphibolite facies gneisses at Grey River, southern Newfoundland, yield a U/Pb zircon age of 686 +33/-15 Ma for the magmatic protolith, whereas metamorphic titanite from the same sample has an age of 579 {plus minus} 10 Ma. Lower grade felsic tuffs north of the gneisses yield an age of 544 {plus minus} 5 Ma and, unlike the gneisses, contain inherited Middle Proterozoic zircons. In the Roti Bay-Clinq Cerf Bay area, lithologically similar gneisses are intruded postmetamorphically by a granitoid complex, from which two plutons yield U-Pb zircon ages of 499 +3/-2 and 563 {plus minus} 4 Ma. These southern Hermitage flexure rocks are vestiges of a unique zone of late Precambrian-earliest Paleozoic crust, and they occupy a position intermediate between the lower Paleozoic Dunnage zone of the central mobile belt and the Precambrian Avalon zone. They may represent surface exposures of the seismically defined deep crustal block that underlies the eastern central mobile belt. These rocks can be correlated in age and tectonic position with rocks at the northwest margin of the Avalon zone elsewhere in the Canadian Appalachians and in Britain.
- OSTI ID:
- 7242932
- Journal Information:
- Geology; (USA), Journal Name: Geology; (USA) Vol. 17:6; ISSN GLGYB; ISSN 0091-7613
- Country of Publication:
- United States
- Language:
- English
Similar Records
Late Precambrian U-Pb ages for the Brookville Gneiss, southern New Brunswick
U-Pb evidence for Permian anatexis and faulting, south-central Connecticut: isotopic constraints on the age of accretion of the Avalon terrane
Reworked pre-Grenville crust and timing of Grenville orogenesis in the southeastern Llano Uplift, Texas: Results from U-Pb geochronometry
Journal Article
·
Wed Oct 31 23:00:00 EST 1990
· Journal of Geology; (USA)
·
OSTI ID:5598807
U-Pb evidence for Permian anatexis and faulting, south-central Connecticut: isotopic constraints on the age of accretion of the Avalon terrane
Conference
·
Mon Dec 31 23:00:00 EST 1984
· Geol. Soc. Am., Abstr. Programs; (United States)
·
OSTI ID:5811428
Reworked pre-Grenville crust and timing of Grenville orogenesis in the southeastern Llano Uplift, Texas: Results from U-Pb geochronometry
Conference
·
Tue Dec 31 23:00:00 EST 1991
· Geological Society of America, Abstracts with Programs; (United States)
·
OSTI ID:5935889
Related Subjects
58 GEOSCIENCES
580000* -- Geosciences
ACTINIDES
AGE ESTIMATION
AMPHIBOLITES
APPALACHIAN MOUNTAINS
CANADA
CONTINENTAL CRUST
CORRELATIONS
EARTH CRUST
ELEMENTS
EUROPE
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GRANITES
IGNEOUS ROCKS
ISLANDS
ISOTOPE DATING
ISOTOPE RATIO
LEAD
METALS
METAMORPHIC ROCKS
MOUNTAINS
NEWFOUNDLAND
NORTH AMERICA
PALEOZOIC ERA
PLUTONIC ROCKS
ROCKS
TECTONICS
TUFF
UNITED KINGDOM
URANIUM
WESTERN EUROPE
580000* -- Geosciences
ACTINIDES
AGE ESTIMATION
AMPHIBOLITES
APPALACHIAN MOUNTAINS
CANADA
CONTINENTAL CRUST
CORRELATIONS
EARTH CRUST
ELEMENTS
EUROPE
GEOLOGIC AGES
GEOLOGIC DEPOSITS
GEOLOGIC FAULTS
GEOLOGIC FRACTURES
GEOLOGIC STRUCTURES
GRANITES
IGNEOUS ROCKS
ISLANDS
ISOTOPE DATING
ISOTOPE RATIO
LEAD
METALS
METAMORPHIC ROCKS
MOUNTAINS
NEWFOUNDLAND
NORTH AMERICA
PALEOZOIC ERA
PLUTONIC ROCKS
ROCKS
TECTONICS
TUFF
UNITED KINGDOM
URANIUM
WESTERN EUROPE