Document Type
Thesis
Abstract
A unique, coarse-grained, unaltered norite pluton crops out in the Grenville Province of Quebec, Canada, just north of the Lac a Jack massif anorthosite. The weathered surface appears off-white with large gray phenocrysts of plagioclase surrounded by dark mafic minerals, resembling a sub-ophitic texture. The pluton is divided into a northern and southern area by a strip of country rock, but the two sections are homogeneous. The pluton is not obviously differentiated, but a more medium grained variety is located in proximity with the contact between the pluton and the country rock. Several jotunite dikes intrude the L’Enfer norite. The medium grained contact rocks and the coarse-grained rocks have similar major and trace element compositions, suggesting that both are close representations of the melt composition. Whole-rock normative An values for the norite show a correlation with spatially associated massif anorthosites, especially the St. Urbain and Lac a Jack anorthosites. High TiO. levels are also correlative with ilmenite ores found associated with massif anorthosites. However, the anorthosites are lacking in olivine and magnetite, which are present in the norite. These comparisons suggest that the L’Enfer norite is related spatially, mineralogically, and chemically with the Grenvillian aged massif anorthosites, but does not represent a parental magma for the anorthosites.
Date Awarded
2003
Department
Geology
Advisor 1
Brent E. Owens
Recommended Citation
Fuhs, Julia, "Field Relationships, Mineralogy, and Geochemistry of the L'Enfer Norite and Possible Relationships with Massif Anorthosites, Grenville Province, Quebec" (2003). Geology Senior Theses. William & Mary. Paper 113.
https://scholarworks.wm.edu/geologyseniors/113
