Architecture of Deep-Marine Interchannel Deposits: Isaac Formation, Windermere Supergroup (Neoproterozoic), Southern Canadian Cordillera

Abstract

The Windermere turbidite system, exposed in the southern Canadian Cordillera, east-central British Columbia, is a continental scale, passive margin, submarine fan system, part of which is well exposed in the Castle Creek study area. Here millimetre- to decametre-scale sedimentological and stratigraphic observations identified five facies in interchannel strata: very thin- to medium-bedded turbidite (F1), thick-bedded turbidite (F2) coarse-tail graded structureless sandstone (F3), mudstone clast breccia (F4) and carbonaceous mudstone (F5) and four architectural elements: channel (AE1), distal levee (AE2), overbank splays (AE3) and crevasse splays (AE4). These elements are assembled into a predictive depositional model that describes the initiation and evolution of sandy splay elements developed in distal levee strata of deep-marine slope channels. These data can be used in hydrocarbon exploration to identify and differentiate splay deposits in core and on seismic, and thereby improve the accuracy of subsurface reservoir models.