A multi-proxy stratigraphic reference outcrop record for Miocene marine sediments of eastern Azerbaijan

Given the semi-isolated nature of the Eastern Paratethys Sea, key markers used in global biostratigraphic schemes are barely recognised. Instead, the biostratigraphic subdivisions of the Paratethyan sedimentary succession is based on faunal response to regional paleoenvironmental changes. In recent years, significant progress has been made in understanding the Middle Miocene to Recent Paratethys stratigraphy by creating integrated high-resolution, absolute age-dated multi-proxy stratigraphic records from outcrop records across the region. In these studies, the focus has predominantly been on marginal, shallow-water environments in which the Paratethys regional stages were originally defined. With this framework now in place, we aim to apply this knowledge to study deeper water, fine-grained sediment successions in which the macrofossil record is poorly developed.

The Gobustan region of eastern Azerbaijan has one of the most continuous outcrop records of Early Cenozoic deep-water sediments in the Eastern Paratethys region. We analysed the classic and widely studied Islamdag section, which exposes the Maykop Formation, and overlying Spirialis and Diatom formations of the Middle and Late Miocene. During fieldworks in 2016-2018, we logged 800 m of section at cm-scale, trenching in places through up to 1 m of weathered material to collect over 450 samples. A subset of around 90 samples have been analysed to develop a multidisciplinary biostratigraphic scheme. In the field, we referred back to stratigraphic subdivisions of the Gobustan area in Russian lithostratigraphic works dating from the 1920’s and 1930’s. These subdivisions and reference levels allow for straightforward correlation between outcrops, and their significance on a regional scale should be tested.

Here, we aim to establish a high-resolution, quantitative and multi-proxy, age-dated stratigraphic framework for these fine-grained marine sediments. The biostratigraphic dataset is predominantly based on palynology (dinoflagellate cysts, acritarchs, green algae, pollen and spores). Additional insights come from sedimentological observations and microfossils. Using our new constraints, we will propose a correlation both to global records, and to previously published biostratigraphic records in other regions in the Eastern Paratethys, including the Taman Peninsula (Southern Russia) on the shore of the Black Sea, to highlight the importance of these results in a Paratethys-wide context.

The Gobustan region of eastern Azerbaijan has one of the most continuous outcrop records of Early Cenozoic deep-water sediments in the Eastern Paratethys region. We analysed the classic and widely studied Islamdag section, which exposes the Maykop Formation, and overlying Spirialis and Diatom formations of the Middle and Late Miocene. During fieldworks in 2016-2018, we logged 800 m of section at cm-scale, trenching in places through up to 1 m of weathered material to collect over 450 samples. A subset of around 90 samples have been analysed to develop a multidisciplinary biostratigraphic scheme. In the field, we referred back to stratigraphic subdivisions of the Gobustan area in Russian lithostratigraphic works dating from the 1920’s and 1930’s. These subdivisions and reference levels allow for straightforward correlation between outcrops, and their significance on a regional scale should be tested.

Here, we aim to establish a high-resolution, quantitative and multi-proxy, age-dated stratigraphic framework for these fine-grained marine sediments. The biostratigraphic dataset is predominantly based on palynology (dinoflagellate cysts, acritarchs, green algae, pollen and spores). Additional insights come from sedimentological observations and microfossils. Using our new constraints, we will propose a correlation both to global records, and to previously published biostratigraphic records in other regions in the Eastern Paratethys, including the Taman Peninsula (Southern Russia) on the shore of the Black Sea, to highlight the importance of these results in a Paratethys-wide context.