Metamorphic effects of the Pabineau Falls Granite, northern New Brunswick, Canada

Abstract

The Pabineau Granite, at the northern end of the Central- Plutonic Belt of the Miramichi Massif in Northern New Brunswick. The granite has been interpreted to be due to magmatic activity during the closing of the Iapetus Ocean in the early Ordovican. Upon emplacement, 392 +81/-7 Ma ago, the magmatic body intruded the metasediments of the Tetagouche Group. The occurrence of biotite, cordierite and andalusite has lead to the understanding of the thermal metamorphic contact aureole which formed at a maximum pressure of 1. 5 Kb and a maximum temperature between 300 and 550 degrees Celsius or approximately five kilometers. Large differences in the metamorphic mineralogy of the Middle River section and the Nepisiguit River section is not yet understood. Only local occurrence of cordierite and andalusite make it impossible to map metamorphic isograds. The occurrence of a isotropic alteration product of cordierite and biotite has also been found in this area.