Gull River Formation

The Gull River Formation is a geological formation of Middle Ordovician age (Caradoc Stage), which outcrops in Ontario, Canada.[1] Lithologically, the formation is dominated by light grey to brown limestones and greenish gray dolomites with thin shale and sandstone interlayers.[2][3]

Gull River Formation
Stratigraphic range: Caradoc
~
Gull River Formation exposed along the shore of Lake St. John, Ramara
TypeFormation
Unit of
Underlies
OverliesShadow Lake Formation
Lithology
PrimaryLimestone, dolomite
OtherShale, sandstone
Location
Region Ontario
 New York
 Pennsylvania
Country Canada
 United States
Type section
Named forGull River
Named byV. J. Okulitch
Year defined1939

Fossil content

Chelicerates
Chelicerates reported from the Gull River Formation
GenusSpeciesPresence MaterialNotesImages
Lunataspis L. borealis Upper Member, Kingston, Ontario.[4] 3 specimens (1 adult & 2 juveniles or subadults).[4] A horseshoe crab.

Acritarchs
Acritarchs reported from the Gull River Formation
GenusSpeciesPresence MaterialNotesImages
Dicommopalla D. rissae Southern Ontario.[5] Also found in the Bobcaygeon Formation.

    References
    1. "Gull River formation". Natural Resources Canada. January 9, 2008. Retrieved January 4, 2015.
    2. Armstrong, Derek K.; Dodge, J. E. P. (2007). Paleozoic Geology of Southern Ontario (PDF). Ontario Geological Survey. p. 4. ISBN 978-1-4249-4526-9.
    3. Armstrong, D. K. (2000). Paleozoic Geology of the Northern Lake Simcoe Area, South-Central Ontario (PDF). Ontario Geological Survey. pp. 9–15. ISBN 978-0--7778--9451--4.
    4. Lamsdell, James C.; Isotalo, Phillip A.; Rudkin, David M.; Martin, Markus J. (October 2022). "A new species of the Ordovician horseshoe crab Lunataspis". Geological Magazine: 1–5. doi:10.1017/S0016756822000875. ISSN 0016-7568. S2CID 252723542.
    5. Bunner, Wendy D.; Legault, J. A. (1989). "A New Species of Dicommopalla (Acritarcha) from the Middle Ordovician Simcoe Group of Southern Ontario, Canada". Palynology. 13: 57–62. doi:10.1080/01916122.1989.9989354. ISSN 0191-6122. JSTOR 3687532.


    This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.