Fluvial sedimentology and stratigraphy of the Late Jurassic–Early Cretaceous Monteith Formation

Abstract

The Late Jurassic – Early Cretaceous Monteith Formation (Minnes Group) records incipient foredeep deposition in the Alberta Deep Basin. The uppermost lithostratigraphic unit, informally referred to as the Monteith A, is investigated with 550 wells and ~540 m of strata from 29 cores across a 17,500 km2 area. These data provide the basis for characterization of fine- grained, organic rich overbank deposits and sandstonedominated channel belts associated with the fluvial stratum. Sediment was delivered from an orogenic catchment (>100, 000 km2) to a fluvial fan that transported sediment northeast to an axial river system, and is interpreted as a distributive fluvial system (DFS). The associated stratigraphic architecture of the DFS fines upward and is characterized by amalgamated channel belts nearest the point source. The interplay between channel belt amalgamation, channel belt architecture, natural fractures, and burial depth control the reservoir quality and distribution in the study area.