Origin and Metamorphism of Part of the Hermon Group Near Bancroft, Ontario

Abstract

<p>A detailed geological and petrochernical study of an upper amphibolite grade, "Grenville Series" sequence is presented. Integrated structural, stratigraphic and geochemical data have led to the conclusion that this seqluence accumulated as an interbanded volcanic and sedimentary prism either in an Upper Proterozoic geosyncline or volcano-tectonic depression .</p> <p>Metamorphic phase assemblages, in general, approach equilibrium. As assemblage showing disequilibrium, "frozen", re - actions are discussed in detail. Experimental data on all the phase assemblages suggests the most probable range of metamorphic conditions to be 625° to 690° and 5. 5 to 7 kilobars total pressure. The 11 effects of retrograde metamorphism on the prograde assemblages are documented.</p>