The Vester Formation is a
geologic formation
A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics ( lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock exp ...
in
Oregon
Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...
which preserves
fossils
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...
dating back to the
Triassic
The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...
period. The partial skeleton of a new genus of basal thalattosaur has been recovered from the Brisbois Member of this formation.
[Metz, Eric T. (2019). ]
Description, phylogenetic analysis and taphonomy of a new Thalattosaur from the Brisbois member of the Vester Formation (Carnian/Norian) of central Oregon
' (ms thesis). University of Alaska Fairbanks. The Brisbois Member, which dates to between the
Carnian and
Norian
The Norian is a division of the Triassic Period. It has the rank of an age (geochronology) or stage (chronostratigraphy). It lasted from ~227 to million years ago. It was preceded by the Carnian and succeeded by the Rhaetian.
Stratigraphic defi ...
, is a marine sequence primarily composed of fine-grained clastic sedimentary rocks with fissile
mudstones of black, green or gray variety broken up by widely spaced intervals of
calcirudite beds and calcareous
conglomerate
Conglomerate or conglomeration may refer to:
* Conglomerate (company)
* Conglomerate (geology)
* Conglomerate (mathematics)
In popular culture:
* The Conglomerate (American group), a production crew and musical group founded by Busta Rhymes
** Co ...
. The formation formed between two parallel island arcs, that of the Baker Terrane and the Olds Ferry Terrane. The formation mostly consists of reworked chert grains from the Baker Terrane.
[Dorsey and LaMaskin, 2007] In addition to the remains of the basal thalattosaur, fragmentary and undescribed remains exist of an ichthyosaur, archosaur, and a hybodontid shark as well as many invertebrate fossils.
See also
*
List of fossiliferous stratigraphic units in Oregon
This article contains a list of fossil-bearing stratigraphic units in the state of Oregon, Oregon, U.S.
Lists of fossiliferous stratigraphic units Cenozoic
Mesozoic
Paleozoic
See also
* Paleontology in Oregon
* Lists of Oregon- ...
*
Paleontology in Oregon The location of the state of Oregon
Paleontology in Oregon refers to paleontological research occurring within or conducted by people from the U.S. state of Oregon. Oregon's geologic record extends back approximately 400 million years ago to the ...
References
Sources
*
Triassic geology of Oregon
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