Ruban, Dmitry1, Wan Yang2
(1) Rostov State University, Rostov-na-Donu, Russia
(2) Wichita State University, Wichita, KS
ABSTRACT: Upper Miocene Sequence Stratigraphy of Rostov Dome, Russian Platform, Eastern Paratethys
Three sequences of Upper Miocene carbonate and siliciclastic successions, deposited on the shelf in Tanais Paleobay of northern Eastern Paratethys, were interpreted in 10 measured sections in Rostov Dome, southern Russian Platform, to establish the first sequence stratigraphic framework in the region. The lower sequence emcompasses Taganrogskaja and Rostovskaja formations. TST consists of dark gray shale (up to 80 m). Shallowing-upward HST (25-30 m) are sandstone intercalated with shale at the base, limestone with molluscs (Cerastoderma, Mactra) in the middle, and interbedded limestone and shale at top, which is capped by a major unconformity.
LST of the middle sequence consists of fluvial deposits with fossil mammals of Janovskaja Fm. (~25 m). Cross-bedded sandstones are incised valley fills because of deep (20-30 m) channel downcutting. TST is a transgressive succession of blue shale with deep-marine fauna, sandstone, marlstone and limestone of Donskaja Fm (~10 m). Upward-thinning HST is the limestone with molluscs (Congeria) of Merzhanovskaja Fm (up to 3 m), capped by an erosional surface.
Limestones with shallow-water bivalves (Monodacna, Prosodacna, Paradacna) and gastropods in Aleksandrovskaja Fm (~10 m) comprise TST of the upper sequence. HST is represented basinward out of studied territory.
The lower, middle, and upper sequences are of 4.5, 3.5-4.0, and 1 Ma duration and coincide well to the transgressive-regressive and salinity cycles of the Eastern Paratethys. The results may be used to construct a new depositional model for this region and to correlate environmental and sea-level changes within the Mediterranean and Paratethys.
AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.