Desmond Cullen HBSc thesis abstract

Thesis Title: 
The Metamorphism of the Quetico Metasediments in the Atikokan Area

The Quetico Belt is an Archean metasedimentary unit, possibly an accretionary prism, over 800 km long within the Superior Province of the Canadian Shield.  It is bounded by the Wabigoon metavolcanic belt to the north and the Shebandowan - Wawa volcanic - plutonic belt to the south.  The sediments within the Quetico belt are primarily greywacke and mudstone turbidities which, toward the centre of the belt, have been folded, progressively metamorphosed, migmatized, and undergone local anatexis with increasing metamorphic grades.

The metamorphic grades observed within the Quetico belt range from lower greenschist facies at the margins to upper amphibolite with concomitant anatexis.  In the study area, the lower grade rocks are characterized by the presence of sericite and chlorite, with increasing grades resulting in the development of biotite, hornblende, garnet, cordierite and staurolite, and increasing calcium content of plagioclase.

The regional metamorphic conditions across the belt have been estimated to range from low greenschist facies conditions near the north and south boundaries through areas at 500°C, 3 kb pressure to 700°C, 4 kb pressure, up to a maximum of 720°C and 4.2 kb pressure.  The metamorphic conditions in this study area probably range form the same lower boundary conditions up to approximately 600°C at 3.5 kb.