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.
| Identifer | oai:union.ndltd.org:uno.edu/oai:scholarworks.uno.edu:td-1946 |
| Date | 15 May 2009 |
| Creators | Tice, Peter |
| Publisher | ScholarWorks@UNO |
| Source Sets | University of New Orleans |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | University of New Orleans Theses and Dissertations |
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