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Stratigraphic and tectonic implications of a newly discovered glacia diamictite cap carbonate couplet in southwestern Mongolia.
- Source :
-
Geology . Feb2009, Vol. 37 Issue 2, p123-126. 4p. 1 Color Photograph, 1 Graph, 1 Map. - Publication Year :
- 2009
-
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. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00917613
- Volume :
- 37
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- Geology
- Publication Type :
- Academic Journal
- Accession number :
- 36511979
- Full Text :
- https://doi.org/10.1130/G24797A.1