Field relationships, petrology, geochemistry, and petrogenesis of quartz dioritic magmas, Whistle Offset, Sudbury structure, Canada

Carter, Wanda M.

doi:10.22215/etd/2005-07669

Cited by 1 publication

(2 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The formation of breccia and quartz dioritic phases along the Whistle offset has been recently described by Carter (2005) and Carter et al (2009). They reported that the three rock types have similar major-element and rare-earth element (REE) compositions which they suggested was due to these rocks being derived from the same protoliths, the basement rocks.…”

Section: Introductionmentioning

confidence: 91%

See 1 more Smart Citation

Emplacement of metabreccia along the Whistle offset dike, Sudbury: implications for post-impact modification of the Sudbury impact structure

Lafrance

McDonald

2014

Can. J. Earth Sci.

View full text Add to dashboard Cite

The Whistle offset dike is a radial dike linked to the ca. 1850 Ma Sudbury Igneous Complex (SIC) in Sudbury, Ontario. It is linked through the funnel-shaped Whistle embayment which formed as a depression along the floor of a superheated impact melt sheet represented by the present-day SIC. The dike consists of metabreccia, quartz diorite, and inclusion-bearing quartz diorite, emplaced in older Archean gneisses and intrusions. Metabreccia has a fine-grained, igneous-textured matrix surrounding Archean basement clasts. It overlaps in major-element compositions (MgO, CaO, SiO 2 ) with the two quartz diorites. The three have similar chondrite-normalized rare-earth element patterns characterized by pronounced negative slopes, i.e., (La/Yb) N = 17-29, and a weak negative Eu anomaly. This suggests that they originated from the same source melts. Metabreccia has higher high-field-strength element (HFSE) ratios, i.e., Gd/Yb, Ce/Yb, Zr/Y, and lower model initial 207 Pb/ 204 Pb isotopic ratios than the two quartz diorites, suggesting that it assimilated more Archean rocks with higher HFSE ratios and lower 207 Pb/ 204 Pb ratios. It formed as SIC melts mixed with melted basement rocks at the SIC-basement contact. This produced a strongly contaminated, inclusion-bearing melt, which drained downward into an offset structure or fault, entrained more fragments plucked from the walls of the fault, and crystallized as metabreccia. Less contaminated quartz diorite was then emplaced in the still-viscous metabreccia during reactivation of the fault caused by isostatic readjustment of the gravitationally unstable crater. More melting, assimilation of clasts, and mixing of SIC melts at the SIC-basement contact produced inclusion-bearing quartz dioritic melts that were emplaced last along the Whistle offset fault.Résumé : Le dyke décalé de Whistle est un dyke radial relié au complexe igné de Sudbury (CIS), Ontario,~1850 Ma. Il y est relié par l'échancrure de Whistle, en forme d'entonnoir, qui s'est formée comme une dépression le long du plancher d'une couche surchauffée de fusion d'impact représentée par le CIS actuel. Le dyke comprend une métabrèche, une diorite quartzique et une diorite quartzique avec des inclusions, mises en place dans d'anciens gneiss et intrusions de l'Archéen. La métabrèche a une matrice à grains fins à texture ignée entourant des clastes du socle archéen. Sa composition d'éléments majeurs (MgO, CaO, SiO 2 ) chevauche celles des deux diorites quartzitiques. Les trois ont des patrons similaires d'éléments de terres rares, normalisés pour la chondrite, caractérisés par des pentes négatives prononcées, soit (La/Yb) N = 17 à 29, et une faible anomalie négative Eu. Cela suggère qu'ils proviennent des mêmes sources de roches en fusion. Les rapports des éléments à forte liaison atomique (HSFE), soit Gd/Yb, Ce/Yb, Zr/Y, de la métabrèche sont plus élevés et ses rapports initiaux modèles 207 Pb/ 204 Pb sont moins élevés que ceux des deux diorites quartziques, suggérant qu'elle a assimilé plus de roches archéennes avec des r...

show abstract

Section: Introductionmentioning

confidence: 91%

“…7d). The sulphide mineralogy and mineral chemistry of these veins and their associated platinum group minerals are described in Carter (2005) and Carter et al (2009).…”

Section: Contact Relationships and Relative Timing Of Emplacementmentioning

confidence: 99%

Emplacement of metabreccia along the Whistle offset dike, Sudbury: implications for post-impact modification of the Sudbury impact structure

Lafrance

McDonald

2014

Can. J. Earth Sci.

View full text Add to dashboard Cite

show abstract

Field relationships, petrology, geochemistry, and petrogenesis of quartz dioritic magmas, Whistle Offset, Sudbury structure, Canada

Cited by 1 publication

References 53 publications

Emplacement of metabreccia along the Whistle offset dike, Sudbury: implications for post-impact modification of the Sudbury impact structure

Emplacement of metabreccia along the Whistle offset dike, Sudbury: implications for post-impact modification of the Sudbury impact structure

Contact Info

Product

Resources

About