A U/Pb age for the Mygatt-Moore Quarry, Upper Jurassic Morrison Formation, Mesa County, Colorado
Keywords:
Morrison Formation, U/Pb dating, CA-TIMS, Dinosaurs, North American JurassicAbstract
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.Downloads
Issue
Section
License
Submission of a manuscript implies that the work described has not been published before (except in the form of an abstract or a part of a lecture, review or thesis) and that is not under consideration for publication elsewhere. If and when the manuscript is accepted for publication, the authors agree to transfer the copyright of their work to the publisher. The copyright covers the exclusive rights to reproduce and distribute the work, all translation rights as well as the rights to publish the work in any electronic form.
Copyright allows you to protect your original material and stop others from using your work without your permission. It means others will generally need to credit you and your work properly, increasing its impact. If you choose to assign copyright to us, as part of the publication process, you will be asked to sign a publishing agreement. This will be after your manuscript has been through the peer-review process, been accepted, and moves into production.
Authors and authors responsibilities: Authorship should be limited to those who have made a significant contribution to the manuscript content. All those who have made significant contribution should be listed as co-authors. It is declared by the author(s) that manuscripts in all categories submitted to the journal and subjects to peer-review have not been published or submitted to any other journal or book. If the manuscript is written by several authors, the corresponding author should be indicated. It is declared that the corresponding author represents all the co-authors in certifying that all of them contributed meaningfully in preparation of the study, and that the final submitted version of the text is approved by all the co-authors. The author(s) should not publish in their study any copied part of the text and or figures from other sources without proper citation or permission (if necessary) – which is plagiarism – and stay in conflict with basal requirements of the authorship. All the authors are obliged to participate in peer review process, providing retractions or corrections of mistakes. The author(s) should indicate (the best in acknowledgements) the financial support and/or program within which the study has been prepared. Affiliation (all authors/co-authors) and corresponding address (main author) must be clearly stated.
Publication ethics and malpractice requirements: the Volumina Jurassica seeks to publish original work in the best possible form and to the highest possible standards. It is necessary to agree upon standards of expected ethical behavior for all parties involved in the act of publishing (authors, editors, peer reviewers, publisher). The Volumina Jurassica ethic statements are based on the guidelines and standards developed and published by the Committee on Publication Ethics (COPE- http://publicationethics.org/).
Anti-plagiarism Policy: Plagiarism is understood in the sense of the “use another person’s ideas or work and pretend that it is own’ (Cambridge Dictionary) or “the practice of taking someone else’s work or ideas and passing them off as one’s own” (Oxford Dictionaries), self-plagiarism (re-use of significant parts of one’s own copyrighted work without citing the original sources).
All articles in the Volumina Jurassica are supposed to be original. Authors submitting manuscript declare that submitted manuscript is original and has not been prepared from other published material. A paper should contain sufficient detail and references to permit others to replicate the work; any used information resources (phrases, data, images) must be appropriately cited or quoted.
Editors: the Volumina Jurassica editor is responsible for deciding which of the articles submitted to the journal should be published. The Volumina Jurassica editor will accept and evaluate manuscripts for their intellectual content only. Editors must not disclose any information about a submitted manuscript to anyone than stakeholders. The excluded from publication procedure are manuscripts which are beyond the scope of the interest of the journal (i.e. presenting the themes not related with the Jurassic System), and those evidently showing research misconduct (published elsewhere before, plagiarisms or bearing fundamental research mistakes). Unpublished manuscripts or materials must not be used in an editor’s own research. All submitted manuscripts will be considered for publication free of charge. When an author discovers a significant error or inaccuracy in own published work, it is the author’s obligation to promptly notify the Publisher and cooperate with the editor to retract or correct the paper.
