Open Access
Subscription Access
Open Access
Subscription Access
Petrogenetic Significance of Zn Distribution, and of Zn/Fe, Zn/Pb Ratios in Granitic Biotites
Subscribe/Renew Journal
The zinc content of biotite is a potentially useful petrogenetic tracer to determine if a granitic pluton formed by magmatism (crystallization-differentiation), metasomatism, or anatexis. This conclusion stems from a geochemical study of Zn distribution, and of Zn/Fe, Zn/Pb ratios in granitic biotites from the 2.7 billion year old Giants Range batholith of northeastern Minnesota, U.S.A. Results show that the zinc contents of biotites from metasomatic granitoids (477 ppm), anatectic tonalites (498 ppm) and their parent metasedimentary rocks (498 ppm) are significantly lower than those characterizing magmatic granites (754 ppm) and magmatic leucogranites (943 ppm). Also, in a magmatically fractionated series of granit c rocks, the Zn contents and Zn/Fe ratios of biotires increase progressively in the sequence tonalite-granodiorite-adamellite-graniteleucogranite, whereas the Zn/Pb ratios decrease.
Subscription
Login to verify subscription
User
Font Size
Information
Abstract Views: 185
PDF Views: 2