Alkali-rich pyroxenite and sovitic carbonatite intruded amphibolite grade metamorphic rocks of the Bancroft terrane, Grenville province, in the Eganville-Pembroke region, Ontario, between 1090 and 1038 Ma ago. Intrusive field relationships, metastable feldspar mineralogy and oxygen isotope geothermometry indicate temperatures of emplacement above 650$ sp circ$C and locally rapid cooling rates. Clinopyroxene compositions from pyroxenites, carbonatites and fenites show identical sodium and iron enrichment trends. REE and C and O isotope ratios in carbonate dikes are typical of carbonatites. The presence in nearby carbonate metasediments of diopside- and apatite-rich skarn zones resulting from regional metamorphism explains the confused state of literature concerning the intrusive suite. Previously recognized resetting of radiogenic isotope systems may have resulted from a regional fenitization event associated with the emplacement of this suite.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.59521 |
| Date | January 1989 |
| Creators | Mungall, James E. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Geological Sciences.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001067169, proquestno: AAIMM63647, Theses scanned by UMI/ProQuest. |
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