Architectural element analysis of paleo submarine fan systems, Hornby and Denman Islands, BC
De Laplante, Ghislain
The basin sediments of the Nanaimo Group comprise the majority of the bedrock in the Gulf islands, and provide an extensive record of ancient depositional environments. While the Nanaimo Group sediments are traditionally considered lithostratigraphically, consisting of clear well-defined boundaries and sequencing of formations, it was observed in the field that these units vary considerably in lateral extent and continuity. While facies models are traditionally applied to sedimentary deposits to interpret the environment of paleo-deposition, we find that the current lithostratigraphic log oversimplifies the depositional environment and does not represent the complex and three-dimensional architecture of the local deposits, limiting the functionality of facies models alone for depositional reconstruction. Instead, architectural analysis of depositional elements, in conjunction with parsed and reorganized facies studies, allows a more realistic perspective of the basin characteristics in which the Nanaimo Group sediments were deposited.