Eocene microphytofossils of Sary-Oba section, northern Aral Sea region
Byulleten' Moskovskogo Obshchestva Ispytateley Prirody, Otdel Geologicheskiy 73(3): 51-55
The paper presents results of phytoplankton studies from Saksaul and Chegan Formations of Sary-Oba section, eastern part of North Aral Sea region. The constant predominance of genus Horologinella and acritarchs with relative poorness of the assemblages can be noted. The presence of Paleogene European zonal markers (Rhombodinium draco, R. longimanum, Areosphaeridium diktioplocus) permit to estimate age of these formations as Bartonian. The appearance of Charlesdowniea cf. clathrata angulosa in the last sample indicates the position of Bartonian-Priabonian transition in uppermost part of Sary-Oba section. The age difference of Chegan Formation in North Aral region and in North Ustyurt can be related to diachronous nature of its boundaries.