PG42A:
Archean Tectonics I

Submit an Abstract to this Session

Session Title - en français: Tectonique archéenne

Session ID#: 6268

Session Description:
Our understanding of Archaean tectonic is constantly changing but there remains significant debate as to (i) the mechanisms for formation of structures in Archaean terrains (e.g. gravity-driven versus horizontal tectonics), (ii) the driving forces for terrane accretion and regional deformation (modern-style plate tectonics versus regional mantle flow, plumes or drips), (iii) interpretation of deep seismic profiles across granite-greenstone belts, and (iv) how sequences of different ages may be juxtaposed (such as shown by recent U-Pb dating in the Superior Province) without evidence for a major tectonic contact. Knowledge of Archean tectonic processes is essential for understanding the formation of volcano-sedimentary belts, plutons and mineralization (Ni-Cu, Au-Ag, Cu-Zn). This session includes presentations of conceptual models,  field observations and geophysical interpretations of Archaean terrains worldwide, with emphasis on regional tectonic models.

Session Description - en français: La connaissance de la tectonique archéenne est en pleine évolution et reste un débat considérable quant aux mécanismes de formation des structures (p. e., les modèles gravitaires versus la tectonique horizontale), aux forces motrices responsables de l'accrétion de terranes et pour la déformation régionale (la tectonique des plaques « moderne » par rapport à l’écoulement du manteau régional,  les panaches mantélliques), à l'interprétation des profils sismiques profonds à travers les terrains archéens, et comment les séquences de différents âges peuvent se côtoyer (récentes datations U-Pb dans la Province du Supérieur) sans preuve d'un contact tectonique majeur. La connaissance de ces processus est essentielle à la compréhension de la formation des ceintures volcano-sédimentaires, des plutons et des minéralisations. Cette session regroupe aussi bien des présentations de modèles théoriques, des observations de terrain et les interprétations géophysiques de terrains archéens dans le monde entier, en mettant l'accent sur les modèles tectoniques régionaux.

OSPA Liaison:  Jean Goutier, Géologie Québec, Rouyn-Noranda, QC, Canada
Chairs:  Jean Goutier, Géologie Québec, Rouyn-Noranda, QC, Canada, Lyal Harris, INRS-ETE, Québec, QC, Canada and Jean H J Bedard, Geological Survey of Canada, Quebec, QC, Canada
Primary Convener:  Jean Goutier, Géologie Québec, Rouyn-Noranda, QC, Canada
Conveners:  Lyal Harris, INRS-ETE, Québec, QC, Canada and Jean H J Bedard, Geological Survey of Canada, Quebec, QC, Canada
Index Terms:

8011 Kinematics of crustal and mantle deformation [STRUCTURAL GEOLOGY]
8038 Regional crustal structure [STRUCTURAL GEOLOGY]
8125 Evolution of the Earth [TECTONOPHYSICS]
8155 Plate motions: general [TECTONOPHYSICS]

Abstracts Submitted to this Session:

PG42A-01
Archaean unstable stagnant lid tectonics (34256)
Jean H J Bedard, Geological Survey of Canada, Quebec, QC, Canada, Tim E Johnson, Curtin University, School of Earth and Planetary Sciences, The Institute for Geoscience Research (TIGeR), Perth, Australia, Craig O'Neill, Queensland University of Technology, Earth and Atmospheric Sciences, Brisbane, QLD, Australia and Lyal Harris, INRS-ETE, Québec, QC, Canada
PG42A-02
Implications from geophysical data for the structural and tectonic evolution of the Superior and Yilgarn cratons (35640)
Lyal B. Harris, INRS-ETE, Québec, Canada and Jean H J Bedard, Geological Survey of Canada, Quebec, QC, Canada
PG42A-03
Komatiite Volcanism: Lithospheric Controls on the Earth’s Hottest Melts and Links to Crustal Growth in the Archean (33105)
David Robert Mole1, Marco L Fiorentini2, Nicolas Thebaud3, Campbell McCuaig3, Kevin F Cassidy3, Chris L Kirkland4, Sandra Romano4, Michael Doublier4, Elena A. Belousova5 and Steve John Barnes1, (1)CSIRO, Perth, Australia, (2)The University of Western Australia, School of Earth Sciences, Crawley, WA, Australia, (3)University of Western Australia, Crawley, WA, Australia, (4)Geological Survey of Western Australia, Perth, Australia, (5)Macquarie University, Department of Earth and Planetary Sciences, Sydney, Australia
PG42A-04
Crustal shortening, pop-down tectonics, fluid channelling and ore transfers within hot lithospheres – implications for Precambrian Cratons (34185)
Denis Gapais1, Justine Jaguin2, Philippe Boulvais1 and Florence Cagnard3, (1)Géosciences Rennes, université de Rennes 1, Rennes, France, (2)CREGU, Université de Nancy, Nancy, France, (3)BRGM, Orléans, France
See more of: Precambrian Geology