| 250px Sabalites sp. palm frond from the Chuckanut Formation | |
| Type | Geological formation |
| Age | Early to Late Eocene |
| Overlies | Nanaimo Group sediments |
| Thickness | up to Template:Convert/m |
| Lithology | |
| Primary | Fluvial |
| Location | |
| Region | Northwest Washington |
The Chuckanut Formation is a geological sequence of terrestrial, fluvial rock found in northwestern Washington, USA, composing part of the Chuckanut Mountains. It is the southern continuation of the British Columbian Huntingdon Formation. [1] The Chuckanut formation is known for tropical Tertiary Period fossils. In sections the formation reaches up to Template:Convert/m, marking it as one of the thickest sequences of fluvial sedimentary rock found in North America.[2] A fossil turtle shell was recovered from the formation at Clark Point in 1960. The specimen was held in the private collection of the finders until 1981 when it was examined at Western Washington University and identified as an indeterminate member of the Testudinoidea superfamily. Reexamination of the fossil in 2000 showed specimen to belong to the Trionychidae family of soft shelled turtles. [3]
Fossil trackways[]
Eocene fossil trackways are found in the Chuckanut Formation, composed of both birds[4] and animals, including mammals and some turtle tracks.[5] It is thought that the Chuckanut Formation shoreline was of riverine environments combined with a large scale "bedding plane" of material deposition. Four deposition or track sites are known.[5]
References[]
- ^ Matthews R. 2007 "Plant macrofossils and palynomorphs from Kanaka Creek, southwestern British Columbia: Paleocene or Eocene?" GSA Cordilleran Section - 103rd Annual Meeting
- ^ Johnson, S. 1984 "Stratigraphy, age, and paleogeography of the Eocene Chuckanut Formation, northwest Washington" Canadian Journal of Earth Sciences 21(1): 92–106
- ^ Mustoe, G. & Girouard, S., Jr 2001 "A fossil trionychid turtle from the early tertiary Chuckanut Formation of Northwestern Washington" Northwest Science 75(3): 211-218
- ^ Mustoe, G. 1993 "Eocene bird tracks from the Chuckanut Formation, northwest Washington" Canadian Journal of Earth Sciences 30(6): 1205–1208
- ^ a b Mustoe, G. 2002 "Eocene Bird, Reptile, and Mammal Tracks from the Chuckanut Formation, Northwest Washington" PALAIOS 17(4):403-413Abstract
