e/Chuckanut Formation

Information
has gloss	eng: The Chuckanut Formation is a geological sequence of marine rock found in northwestern Washington, USA, on the west side of the Cascade Range, composing part of the Chuckanut Mountains. Its northern continuation is the British Columbian Huntingdon Formation, its southern boundary is approximately at the Darrington-Devils Mountain Fault. It is believed to be related to the Swuak Formation (in the vicinity of Roslyn, Washington), approximately 160 km to the south and on the east side of the Cascade Range. The Chuckanut formation is known for tropical Tertiary Period fossils. In sections the formation reaches up to , marking it as one of the thickest sequences of fluvial sedimentary rock found in North America. 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.
lexicalization	eng: Chuckanut Formation
instance of	c/Geologic formations of the United States