Sedimentary characteristics of the Spray River Group of west-central Alberta.

摘要

Triassic lithologies in west-central Alberta are divided into the Sulphur Mountain Formation and Whitehorse Formation of the Spray River Group. The Sulphur Mountain Formation is subdivided into three members: the Vega-Phroso Siltstone, Whistler, and Llama members. The Whitehorse Formation is subdivided into three members: the Starlight Evaporite, Brewster Limestone, and Winnifred members. Analysis of six outcrops in the Willmore Wilderness Park for this study suggests that the Whitehorse Formation was emplaced in an overall progradational system with occasional regressive transgressive deposition.;From outcrop analysis five facies associations (1, 2, 3, 4 and 5) were developed based on fifteen identified facies. The five associations relate to offshore deposits (1), offshore to shoreface (2), ephemeral/lacustrine supratidal (3), aeolian sabkha depositional environments (4), and offshore turbidite deposits (5). Ichnological, biostratigraphic, and chemostratigraphic analyses of outcrop samples were used in delineating the Sulphur Mountain Formation and Whitehorse Formation of the Spray River Group.