A U/Pb age for the Mygatt-Moore Quarry, Upper Jurassic Morrison Formation, Mesa County, Colorado

• Autorzy: Trujillo K. , Foster J. , Hunt-Foster R. , Chamberlain K.

Identyfikatory

DOI

10.5604/17313708 .1130132

• Języki publikacji: EN

Abstrakty

EN

Mygatt-Moore Quarry in the Brushy Basin Member of the Upper Jurassic Morrison Formation is one of the more important large dinosaur quarries in the formation, yielding fossils of sauropod dinosaurs including Apatosaurus, Camarasaurus, and an indeterminate diplodocine (cf. Diplodocus or Barosaurus), the theropod dinosaurs Allosaurus and Ceratosaurus, and the ornithischians Othnielosaurus and Mymoorapelta. Fossil wood and carbonized plants are known from the deposit, and carbonized dinosaur skin has also been discovered. We report here on a new U/Pb radiometric age for the Mygatt-Moore Quarry, from a smectitic mudstone collected at the quarry horizon. We isolated zircons using an ultrasonic separation technique and standard heavy liquid and magnetic methods, analyzed single zircons using a chemical abrasion method (CA-TIMS). The age determined for this dinosaur quarry, 152.18 ±0.29 Ma, places the quarry at the boundary between the Kimmeridgian and Tithonian stages of the Late Jurassic Period. This age can now be used to place the quarry into stratigraphic position with respect to other dated horizons in the Morrison Formation and other rock units worldwide. We will also use this age along with other ages to create a radiometrically based stratigraphic framework for the Morrison Formation.

Słowa kluczowe

EN

Morrison Formation; U-Pb dating; CA-TIMS; dinosaurs; North American Jurassic

PL

formacja Morrisona; CA-TIMS; dinozaury

• Wydawca: Państwowy Instytut Geologiczny - Państwowy Instytut Badawczy
• Czasopismo: Volumina Jurassica
• Rocznik: 2014
• Tom: Vol. 12, no. 2
• Strony: 107--114
• Opis fizyczny: Bibliogr. 26 poz.

Twórcy

autor

Trujillo K.

• Uinta Paleontological Associates, Inc., Laramie, WY, USA

autor

Foster J.

• Museum of Moab, Moab, UT

autor

Hunt-Foster R.

• Bureau of Land Management, Canyon Country District, Moab, UT, USA

autor

Chamberlain K.

• Department of Geology and Geophysics, The University of Wyoming, Laramie, WY, USA

Bibliografia

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