Mineralogy of Eudialyte Group Minerals From the East Hill Suite Of the Mont Saint-Hilaire Alkaline Plutonic Complex, Including an Alternative Site-Assignment Algorithm & A Proposed Classification System
Date of Award
Earth and Environmental Sciences
Simmons, William B.
Falster, Alexander U.
The twenty approved members of the eudialyte group are complex zirconosilicates, primarily with general formula N15M(1)6M(2)3M(3)M(4)Z3[Si24O72]O4X2. An algorithm was created to address the inherent recalculation difficulties in the absence of single-crystal X-ray data and was an overall improvement over previous schemes. Eudialyte group minerals were analyzed from the East Hill Suite of the Mont Saint-Hilaire alkaline complex. Recalculations revealed previously undocumented eudialyte-group compositions and degrees of chemical zonation. These data suggest that late-stage melt heterogeneity in alkaline systems is far more pronounced than previously thought. All analyses exhibited a negative neodymium anomaly in chondrite-normalized data. This supports data from other investigators that point to a preintrusion fractionation event in the underlying mantle. Potassium content of the eudialyte group minerals from the East Hill Suite was restricted to a narrow range, as was that of analyses from numerous other localities, suggesting some internal control on potassium content in eudialyte group minerals.
Tice, Peter, "Mineralogy of Eudialyte Group Minerals From the East Hill Suite Of the Mont Saint-Hilaire Alkaline Plutonic Complex, Including an Alternative Site-Assignment Algorithm & A Proposed Classification System" (2009). University of New Orleans Theses and Dissertations. 965.