Microfauna of Akchagylsky series of Absheron Archipelago
The paper considers the history of Akchagylsky microfauna and stratigraphy studies in the Absheron Archipelago situated on the western shelf of the Caspian Sea. There are four stages in paleontological studies of sediment rock associations within the Akchagylsky Regional Stage (the first stage — until 1935; second — 1936–1955; third — 1956–1990, fourth — from 1991 up to the present). The obtained data showed that Akchagylsky deposits can be tracked in different directions, and they have different thickness in certain areas of the Absheron Archipelago (Darwin, Bakhar, Goshadash, Absheron, Khazri banks, Pirallahi, Gum, Chilov islands, etc.). In addition, the paper presents the recent microfaunistic researches of the Akchagylsky deposits carried out by the author. The examined core samples, which were taken from the wells drilled on the Absheron Archipelago, are characterised by microfauna determined up to the species, where possible. The obtained results are assigned to the classes and compared with the available data, which allowed identifying three microfaunal zones within the Akchagylsky series of the Absheron Archipelago, namely: two Lower Akchagylsky — foraminifera zone (Cassidulina) and ostracode zone (Candona); and one Upper Akchagylsky — ostracode zone (Leptocythere). Scheme of structures within the Absheron Archipelago and table of stratigraphic distribution of microfauna within Akchagylsky series are created. During the research, a photo collection of selected microfauna species was created using a scanning microscope.
Key words: Absheron Archipelago; Akchagylsky series; microfauna; regional stage; ostracodes; foraminifera; stratigraphy; core; coring wells.
For citation: Mamedova Sh.G. Microfauna of Akchagylsky series of Absheron Archipelago. Geologiya nefti i gaza = Oil and gas geology. 2019;(4):49–57. DOI: 10.31087/0016-7894-2019-4-49-57.
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