A revised model for the crustal structure of the SW Grenville Province, Ontario, Canada

作者:Dickin Alan*; Strong Jacob; Arcuri Gabriel; Van Kessel Annika; Krivankova Smal Lucia
来源:Geological Magazine, 2017, 154(4): 903-913.
DOI:10.1017/S001675681700005X

摘要

The Grenville Province forms the exhumed remnants of a 1.1 Ga collisional orogeny that telescoped an older continental margin. Terranes with distinct crustal formation ages can be mapped using Nd isotopes, revealing a ramp-flat thrust structure. The ramp is identified by the presence of retrogressed eclogites, and its trajectory is refined using Nd model ages. The main allochthon is locally overlain by the Parry Sound klippe, but is also underlain by a tectonic duplex. Northwest-directed nappes represent remnants of a corrugated thrust sheet, but a ring-shaped remnant was also preserved where the thrust sheet was down-buckled under the dense rocks of Parry Sound domain.

  • 出版日期2017-7