High-resolution ion-microprobe measurement of lead isotopes: Variations within single zircons from Lac Seul, northwestern Ontario

1979 ◽  
Vol 45 (2) ◽  
pp. 309-325 ◽  
Author(s):  
R.W. Hinton ◽  
J.V.P. Long
2014 ◽  
Vol 14 (3) ◽  
pp. 3-18 ◽  
Author(s):  
Kei Sato ◽  
Colombo Celso Gaeta Tassinari ◽  
Miguel Angelo Stipp Basei ◽  
Oswaldo Siga Júnior ◽  
Artur Takashi Onoe ◽  
...  

1988 ◽  
Vol 24 (2-3) ◽  
pp. 97-113 ◽  
Author(s):  
R. Levi-Setti ◽  
J.M. Chabala ◽  
Y.L. Wang

1983 ◽  
Vol 9 (4) ◽  
pp. 443-458 ◽  
Author(s):  
R C Thompson ◽  
M Anselment ◽  
K Bekk ◽  
S Goring ◽  
A Hanser ◽  
...  

Geosphere ◽  
2019 ◽  
Vol 16 (1) ◽  
pp. 229-257 ◽  
Author(s):  
Peter M. Valley ◽  
Gregory J. Walsh ◽  
Arthur J. Merschat ◽  
Ryan J. McAleer

Abstract U-Pb zircon geochronology by sensitive high-resolution ion microprobe–reverse geometry (SHRIMP-RG) on 11 plutonic rocks and two volcanic rocks from the Bronson Hill arc in western New Hampshire yielded Early to Late Ordovician ages ranging from 475 to 445 Ma. Ages from Oliverian Plutonic Suite rocks that intrude a largely mafic lower section of the Ammonoosuc Volcanics ranged from 474.8 ± 5.2 to 460.2 ± 3.4 Ma. Metamorphosed felsic volcanic rocks from within the Ammonoosuc Volcanics yielded ages of 460.1 ± 2.4 and 455.0 ± 11 Ma. Younger Oliverian Plutonic Suite rocks that either intrude both the upper and lower Ammonoosuc Volcanics or Partridge Formation ranged in age from 456.1 ± 6.7 Ma to 445.2 ± 6.7 Ma. These new data and previously published results document extended magmatism for >30 m.y. The ages, along with the lack of mappable structural discontinuities between the plutons and their volcanic cover, suggest that the Bronson Hill arc was part of a relatively long-lived composite arc. The Early to Late Ordovician ages presented here overlap with previously determined igneous U-Pb zircon ages in the Shelburne Falls arc to the west, suggesting that the Bronson Hill arc and the Shelburne Falls arc could be part of one, long-lived composite arc system, in agreement with the interpretation that the Iapetus suture (Red Indian Line) lies to the west of the Shelburne Falls–Bronson Hill arc system.


2015 ◽  
Vol 43 (12) ◽  
pp. 1888-1894
Author(s):  
Tao LONG ◽  
Jian SHI ◽  
Ze-Min BAO ◽  
Stephen W.J. Clement ◽  
Yu-Hai ZHANG ◽  
...  

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