The Fernie Formation consists of marine sediments that were deposited in the
Sundance Sea. Deposition took place throughout most of the Jurassic period, starting during the
Hettangian stage in some parts of northeastern British Columbia and continuing until the
mid-Tithonian, as determined from its fossil assemblages, including
ammonites,
molluscs and
microfossils. The sediments were sourced from the east during the deposition of the lower and middle units of the Fernie, where the coarser
facies occur in the eastern part of the formation. In the uppermost Fernie, the coarsest material is found in the west, however, indicating a shift to sources in the west and south. ==Lithology==