Biostratigraphy and Paleoenvironments of the Productive Series and Adjacent Units, Kura Depression Area, Eastern Azerbaijan
- The executive companies: Geology Institute, Amoco
- The year of publication: February 1996
- Code: # 951033
- Volumes: total 1. Volumes with appendixes in same amount: 1
This report summarizes the results of a joint study involving paleontologists from the Geology Institute of Azerbaijan National Academy of Sciences and Amoco EPTG Paleontology group. The project involved collecting and analyzing samples from the Productive Series and adjacent units at four localities in the Kura River drainage basin and the western Azerbaijan Peninsula. Results have been integrated with previously acquired data to produce a biostratigraphic and paleoenvironmental synthesis for eastern Azerbaijan.
Biostratigraphic data generated in the course of this analysis were graphically correlated against Amoco C-Azeri composite standard to yield precise age interpretations for the Pontian through Absheron interval. These data are supplemented in places by osotopic age dates derived from our own collections and from previously published reports. Graphic correaltion results show that regional unconformities are developed at the Plio-Pleistocene contact (1.8 Ma;=Akchagyl- Apsheron boundary); at the contact between the Upper Productive Series and Akchagyl (4.3-2.6 Ma;= Seismic Horizon 1); at the base of the Pereriva Suite (5.3 Ma;=Seismic Horizon 2); at the base of the Productive Series (5.8-5.6 Ma;=Seismic Horizon 3); and within the middle Pontian (approx. 6.8-5.8 Ma;=Messinian Event). Moreover, intra-sequence biostratigraphic subdivisons are possible within the lower and upper portions of the Productive Series. The level of biostratigraphic resolution within the Productive Series is adequate to confirm or refute tenuous seismic and/or log correlations.
Paleoenvironmental interpretations indicate that the lower Pontion was fluviodeltaic. Middle and upper Pontian deposits accumulated inmore open-basin environments, 30- 50 m in depth, with stable paleosalinities of 15-18 ‰ . The overlying Lower Productive Series accumulated in progressively shallower and less saline waters. Deposition of the Kirmaky through NKG suites reflects the transiton from nearly marine conditions in the Pontian to closed-basin, low salinity, deltaic facies in the Upper Productive Series. By Sabunchi time, the Caspian Basin was completely isolated from the world ocean and supported an endemic biota. Water depths during Sabunchi-Surakhany deposition were extremely shallow (<5 m) and paleosalinities did not exceed 2‰. Palynomorhs recovered form the uppermost Productive Series are indicative of relatively wet climatic conditions. The Caspian Basin experienced a very brief marine incursion at the beginning of Akchagyl time. Quickly thereafter, the basin again became isolated with an endemic biota and paleosalinities in the range of 8-14 ‰ . Akchagylian palynomorphs indicate very arid conditons, consistent with the onset of worldwide glaciation.
1.0 Executive Summary
3.0 Babazanan (Paleo Locality 17891)
4.0 Sundi (Paleo Locality 17893)
5.0 Geylar Village (Paleo Locality 17892)
6.0 Sumgayit Station (Paleo Locality 17894)
7.0 Composite Standard