Lincoln Creek Formation

The first locality of the Lincoln Creek formation was found, as the name suggests, at Lincoln Creek which is located within Lincoln County, Washington. Due to the outcrops being small in the area, the type locality of the formation is located in an area along the Chehalis River which consists of around 366 m of offshore marine strata. The formation was originally named the Lincoln formation by Weaver in 1912 though that name was already used for the Lincoln Porphyry, an Eocene deposit in Colorado. == Description ==

The Lincoln Creek formation is a wide-spanning formation in Washington with numerous outcrops spanning from the Columbia River to Olympic Mountains; measurement of the formation suggest in spans are 3885 square kilometers. In these sections, the Lincoln Creek formation is around 3000 m thick. The thickness of the formation increases as one goes west and north within the basin. The formation is largely made up of mudstone and siltstone with the sandstone more common in the lower strata of the formation ranging from fine to very-fine grained. Within the strata, there are also thin layers of calcareous concretions, basaltic sandstone, glauconitic sandstone, and structureless mudstone present. One notable feature of the lithology is the fact that in on the eastern edges, pyroclastic rock is present within a largely basaltic sandstone member. Along with that, small sections of limestone are present due to hydrocarbon seeps that were in the area during time of deposition. The basal most 122 meters of the formation in made up of tuffaceous sandstone and sandy siltstone which overlies the Eocene Skookumchuck Formation. == Paleobiota ==

Anthozoa Annelida Aves Crustacea Echinodermata Mollusca Mammalia Osteichthyes Porifera == Paleoenvironment ==

The Lincoln Creek formation represents a continuous marine shelf and shelf slope environment with turbidity currents present. Though the microfauna suggests a depth of potentially over 1000 m, the mollusk fauna only suggests that the deposition would have been much shallower, ranging from 100 to 350 m. Evidence of both whale and wood falls have been found at the formation with taxa present in these events today. ==References==