Stratigraphic and tectonic implications of a newly discovered glacial diamictite–cap carbonate couplet in southwestern Mongolia

Abstract

Research Article| February 01, 2009 Stratigraphic and tectonic implications of a newly discovered glacial diamictite–cap carbonate couplet in southwestern Mongolia Francis A. Macdonald; Francis A. Macdonald * 1Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA *E-mail: fmacdon@fas.harvard.edu. Search for other works by this author on: GSW Google Scholar David S. Jones; David S. Jones 1Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA Search for other works by this author on: GSW Google Scholar Daniel P. Schrag Daniel P. Schrag 1Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA Search for other works by this author on: GSW Google Scholar Author and Article Information Francis A. Macdonald * 1Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA David S. Jones 1Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA Daniel P. Schrag 1Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138, USA *E-mail: fmacdon@fas.harvard.edu. Publisher: Geological Society of America Received: 21 Jan 2008 Revision Received: 23 Sep 2008 Accepted: 06 Oct 2008 First Online: 12 Oct 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 © 2009 Geological Society of America Geology (2009) 37 (2): 123–126. https://doi.org/10.1130/G24797A.1 Article history Received: 21 Jan 2008 Revision Received: 23 Sep 2008 Accepted: 06 Oct 2008 First Online: 12 Oct 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Francis A. Macdonald, David S. Jones, Daniel P. Schrag; Stratigraphic and tectonic implications of a newly discovered glacial diamictite–cap carbonate couplet in southwestern Mongolia. Geology 2009;; 37 (2): 123–126. doi: https://doi.org/10.1130/G24797A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract We report here the discovery of a new end-Cryogenian glacial diamictite and an overlying basal Ediacaran cap carbonate within the Tsagaan Oloom Formation of southwestern Mongolia. The identification of the Cryogenian-Ediacaran boundary, coupled with new δ13C chemostratigraphic profiles, facilitates the integration of the Neoproterozoic stratigraphy of Mongolia with records elsewhere. These correlations indicate that a previously unrecognized, −16‰ Cryogenian δ13C anomaly is present in the newly defined Tayshir member (informal) of the Tsagaan Oloom Formation. Furthermore, chemostratigraphic and lithostratigraphic relationships suggest an ~35 m.y. depositional hiatus below the phosphorite-bearing Zunne Arts member (informal) of the upper Tsagaan Oloom Formation and that subsidence renewed in the latest Ediacaran–Early Cambrian. We propose that the lower ~1500 m of the Tsagaan Oloom Formation was deposited on a thermally subsiding passive margin after Rodiniaage rifting, whereas the Zunne Arts member and the overlying ~1600 m of Early Cambrian strata were deposited in a foredeep basin that formed as the southern margin of the Dzabkhan terrane was subducted beneath the Khantayshir-Dariv arc. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.