Regional metamorphism of the Appalachian Humber zone of Gaspé Peninsula: 40 Ar/ 39 Ar evidence for crustal thickening during the Taconian orogeny

Geochronological studies on the timing of deformation and metamorphism along the Laurentian margin have shown that the ages of metamorphic events change along-strike within the Newfoundland – southern Quebec segment of the Canadian Appalachians. The Gaspé Peninsula is located at mid-point of the two...

Full description

Bibliographic Details
Published in:Canadian Journal of Earth Sciences
Main Authors: Pincivy, Alix, Malo, Michel, Ruffet, Gilles, Tremblay, Alain, Sacks, Paul E
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2003
Subjects:
Newfoundland
Online Access:http://dx.doi.org/10.1139/e02-076
http://www.nrcresearchpress.com/doi/pdf/10.1139/e02-076
Description
Summary:Geochronological studies on the timing of deformation and metamorphism along the Laurentian margin have shown that the ages of metamorphic events change along-strike within the Newfoundland – southern Quebec segment of the Canadian Appalachians. The Gaspé Peninsula is located at mid-point of the two extremities of this segment. New single-grain laser 40 Ar/ 39 Ar plateau ages solely reflect latest Middle–Late Ordovician metamorphism. Samples taken within the internal Humber zone in the Shickshock Group rocks yield 40 Ar/ 39 Ar muscovite and hornblende ages ranging from 457 to 454 Ma. Samples from the Amphibolite du Diable, the metamorphic sole of the Mont Albert ophiolite, yield 40 Ar/ 39 Ar muscovite and hornblende ages ranging from 459 to 457 Ma. Ordovician ages of the internal Humber zone are consistent with 40 Ar/ 39 Ar ages from southern Quebec and are interpreted as the result of the emplacement onto the margin of both the ophiolite and its metamorphic sole.

Similar Items