RT Journal Article
T1 Biological turnovers in response to marine incursion into the Caspian Sea at the Plio-Pleistocene transition
A1 Hoyle, Thomas M.
A1 Leroy, Suzanne A.G.
A1 López Merino, Lourdes
A1 van Baak, Christiaan G.C.
A1 Martínez Cortizas, Antonio
A1 Richards, Keith
A1 Aghayeva, Vusala
AB Marine influence on low-salinity environments can trigger aquatic ecosystem shifts, including biodiversity turnovers. High-resolution palaeoenvironmental records of marine connection events are particularly valuable, as they provide natural laboratories to understand analogous oceanographic and biodiversity turnover events in present-day climate- and anthropogenically-induced incursions. One such incursion event occurred across the Plio-Pleistocene transition when water from the open ocean spilled into the Eurasian continental interior, inundating the Caspian area. Here we record the so-called Akchagylian marine incursion using well-dated palynological and geochemical records of the Lokbatan section (Azerbaijan). Immediately prior to the intensification of northern hemisphere glaciations (~2.75 Ma), fresh-brackish peri-Paratethyan dinocyst assemblages were replaced by monospecific assemblages of the marine dinocyst, Operculodinium centrocarpum sensu Wall and Dale (1966). This indicates that the Caspian Sea experienced a marine incursion during a period of global high sea level. The marine incursion also registered in the geochemical record as a peak in excess‑strontium and carbonate content. Marine influence on the Caspian ceased after ~2.46 Ma and a second biological turnover took place, with low-salinity tolerant peri-Paratethyan dinoflagellate communities replacing the marine assemblages. The large-scale Akchagylian marine incursion episode shows the extreme degree of biodiversity change that marine influence on fresh-brackish water basins could trigger. Similar processes are increasingly relevant to present-day marginal and landlocked basins, which face ever-greater incursions from marine species and water due to both climate-mediated sea-level rise and human-made infrastructure projects.
PB Elsevier
YR 2021
FD 2021-09-03
LK https://hdl.handle.net/20.500.14352/129915
UL https://hdl.handle.net/20.500.14352/129915
LA eng
NO Hoyle TM, Leroy SAG, López-Merino L, et al. Biological turnovers in response to marine incursion into the Caspian Sea at the Plio-Pleistocene transition. Global and Planetary Change 2021;206:103623. https://doi.org/10.1016/j.gloplacha.2021.103623
NO BP Exploration Operating Company Limited
NO Comunidad de Madrid (España)
DS Docta Complutense
RD 17 mar 2026