| Title | How many arcs can dance on the head of a plume? - A 'comment' on: A critical assessment of neoarchean 'plume only' geodynamics: Evidence from the Superior province, by Derek Wyman. Precambrian Research,
2012 |
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| Author | Bédard, J H |
| Source | Precambrian Research vol. 229, 2013 p. 189-197, https://doi.org/10.1016/j.precamres.2012.05.004 |
| Image |  |
| Year | 2013 |
| Alt Series | Earth Sciences Sector, Contribution Series 20120027 |
| Publisher | Elsevier BV |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf |
| Subjects | igneous and metamorphic petrology; tectonics; Archean; igneous rocks; craton; plutonic rocks; ophiolites; magmatism; magmatic arcs; tectonic setting; Superior Province; Precambrian |
| Program | Targeted Geoscience Initiative (TGI-3), 2005-2010 |
| Released | 2013 05 01 |
| Abstract | Bedard (2006) proposed that Archaean cratons formed above large, long-lived mantle plumes, where the thick basaltic crust cannibalized itself to generate TTGs (tonalite-trondhjemite-granodiorite) and
complementary eclogitic restites. In this model the dense eclogitic restites foundered into the depleted upper mantle and refertilized it, triggering generation of new basaltic melt pulses, and so eclogite represents a catalyst for coupled crust -
mantle differentiation. Since most of the eclogite is destroyed in the upper mantle, voluminous hidden eclogitic reservoirs are not predicted. The model was not intended to explain the generation of overprinting fabrics and terrane assembly, but to
account for chemical evolution of the coupled crust - mantle system in the initial stages of craton development. Wyman (2013) argues that the models and hypotheses presented in Bedard (2006) are unrealistic and irrelevant, and reaffirms his opinion
that the Archaean world was dominated by plate tectonics. The criticisms and arguments of Wyman (2013) are invalid. |
| GEOSCAN ID | 291389 |
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