Source rock prospectivity of lower Carboniferous lacustrine strata, Anguille Group, Conche, Newfoundland

Abstract

In Eastern Canada, in a regional Carboniferous rift system (Maritimes Basin Tectonostratigraphic Zone), there are lacustrine basins containing petroliferous source rocks. Near the northern limits for this complex, strata of the Cape Rouge Formation at Conche, Newfoundland, are thought to represent a nearby onshore facies analog for rocks laying farther offshore in the St. Anthony Basin. Four facies assemblages of mixed sandstone, siltstone, dolostone and black mudstone represent distinct stages of an underfilled lake-basin developed within a half-graben depocenter. The finest-grained facies assemblage, with TOC between 0.23-6.54 wt.%, has organic matter dominated by Type 1 kerogen. Maturation analysis places strata within the oil-generation window (Rₒ=0.5-1.01%); however, Rock-Eval results indicate little remaining potential for generating hydrocarbons. Based on findings from Conche, the St. Anthony Basin may contain similar half-graben lake-basins with Carboniferous source rock potential. However, source quality and timing for oil generation remain key risks for hydrocarbon exploration offshore.