Bulletin of Canadian Petroleum Geology, Vol.49, No.2, 186-201, 2001
Stratigraphy, tectono-sedimentary evolution and paleogeography of the post-Taconian-pre-Carboniferous Gaspe Belt: an overview
This contribution provides an overview of the geological setting, stratigraphy, tectono-sedimentary evolution, and paleogeography of the post-Taconian-pre-Carboniferous sequence of the Gaspe Belt. The sequence has been shaped by two tectonic pulses: the Salinic disturbance that began during the Early Silurian (Telychian) and persisted until the Early Devonian (Pragian), and the ensuing Acadian Orogeny in the Early to Mid-Devonian (Emsian-Eifelian). The shelf and shelf-edge history at the Laurentian margin along the Quebec Re-entrant-St. Lawrence Promontory can be summarized in five broad phases that resulted from the interplay of tectonics and sea-level change. Phase I is a Llandoverian-Wenlockian regressive phase (RI) related to post-Taconian successor basin infilling, which culminated in extensive carbonate platform development. Phase 2 is a late Wenlockian-Ludlovian transgressive phase (TI). Phase 3 corresponds to a later Ludlovian-Pridolian second regressive phase (R-2)- Phases 2 and 3 were accompanied by extension faulting. block tilting, and the development of reefs, reef complexes and reef tracts along the Gaspe-Temiscouata shelf. Phase 4 is an Early Devonian phase of accelerated subsidence (transgression T-2) affecting the northwestern part (Quebec Re-entrant area), while the southeastern part (St-Lawrence Promontory area) was previously uplifted as a result of Laurentia colliding with the western margin of Gondwana-related terranes to the south. Phase 5 is the final regression (R-3) related to the Acadian Orogeny.