麻豆传媒

The peraluminous granites of Nova Scotia and Morocco are compared to assess the viability of the Moroccan Model that postulates that the Meguma Zone (a suspect terrane of the northern Appalachians) was derived from north-western Africa. In addition, the relationship between the so-called northern and southern plutons of Nova Scotia are examined. A geochemical database of over 1300 peraluminous granite analyses from Nova Scotia, Morocco, Iberia (another potential source area) and, Australia (a presumably unrelated belt) was carefully compiled for this study. The geochemical data were examined using both a traditional approach and discriminate function analysis multivariate statistical technique).

Results obtained by traditional methods of comparison indicate that the northern and southern plutons of Nova Scotia, although different, could not be clearly separated into two groups. In addition, the granites of Nova Scotia and Morocco appear indistinguishable.

Various statistical models demonstrate the applicability of discriminant analysis to the geochemical compositional granitic data by successfully analyzing, bimodal and skewed populations, uneven sample groups and, compositional data.

A number of statistical models compare the geochemical populations of northern and southern Nova Scotia; Nova Scotia and Morocco; Nova Scotia, Morocco and, Iberia and; the Atlantic and Australia granites. Results indicate that the northern and southern plutons of Nova Scotia appear geochemically distinct; the Nova Scotia and Morocco populations show some similarities; Nova Scotia, Morocco (Zaer pluton of the Central Massif) and Iberia are equally similar; and, the Atlantic and Australia granites are clearly distinct.

Comparison of discriminant function coefficients obtained on the local (north-south Nova Scotia), regional (Nova Scotia-Morocco and Nova Scotia-Morocco-Iberia) and orogenic scale (Atlantic and Australian granites) show that within each scale of reference a characteristic suite of elements can be defined and are good discriminators.

Results obtained throughout this study indicate that discriminant function analysis are more useful and revealing than traditional methods of comparisons. Although no clear evidence was found to confirm the Moroccan Model, results suggest that Morocco can not be excluded as a potential source area for the Meguma Terrane.

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Pages: 362
Supervisor: D. Barrie Clarke