Provenance, diagenesis and reservoir quality of the Upper Triassic Wolfville Formation, Bay of Fundy, Nova Scotia, Canada

Abstract

AbstractThe reservoir characterization and provenance of the Wolfville Formation were investigated using petrography, heavy minerals and microprobe analysis of tourmaline and garnet. Sandstone samples were taken from exposures at Rainy Cove and Cambridge Cove, and from the subsurface at Chinampas N-37 well beneath the Bay of Fundy. The surface and subsurface rocks have differences in their relative content and/or type of detritus, cement and heavy minerals (opaques, garnet, scheelite, tourmaline, rutile, apatite and others). These sandstones have continental block provenance in the subsurface rocks and recycled orogen provenance in the exposures. The main sources of the exposed Wolfville Formation sediments were the Palaeozoic rocks of the Meguma Supergroup, South Mountain Batholith, Horton and Windsor groups; meanwhile the subsurface sandstones might have been derived from the same sources or the Avalon Terrane and/or Gondwana. The sandstones were deposited during early stages of rifting post-dating earlier Palaeozoic collision orogenies that culminated with the Appalachian orogeny. The exposures of Wolfville Formation have low porosity (c. 6%) that diminishes to negligible in the subsurface. The Wolfville Formation has a considerable thickness beneath the Bay of Fundy where it overlies the Horton Bluff Formation, Meguma and/or Avalon terranes. However, its reservoir potential is not encouraging.