Multidisciplinary Study of the Rybachya Core in the North Caspian Sea during the Holocene
Mollusk fauna is an important component of the Caspian Sea ecosystem alongside ostracods and diatoms. These faunal proxies are essential indicators of hydrological shifts reflecting global and regional climate changes. Adding lithological, geochemical, and geochronological (radiocarbon) data, we rev...
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MDPI AG
2023-01-01
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| Online Access: | https://www.mdpi.com/1424-2818/15/2/150 |
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| author | Alina Berdnikova Elena Lysenko Radik Makshaev Maria Zenina Tamara Yanina |
| author_facet | Alina Berdnikova Elena Lysenko Radik Makshaev Maria Zenina Tamara Yanina |
| author_sort | Alina Berdnikova |
| collection | DOAJ |
| description | Mollusk fauna is an important component of the Caspian Sea ecosystem alongside ostracods and diatoms. These faunal proxies are essential indicators of hydrological shifts reflecting global and regional climate changes. Adding lithological, geochemical, and geochronological (radiocarbon) data, we revealed paleogeographic events of different scales recorded in the sequence of the Rybachya core from the North Caspian Sea. Here, we present the reconstruction of Mangyshlak paleovalley sediments during the Holocene multi-stage Neocaspian transgression, reflecting global and regional climate changes varying in scale and direction. The determined age of paleovalley-fill sediments, 8070 ± 110 cal yr BP and 7020 ± 140 cal yr BP, suggests that sedimentation processes with extended warming and humidification started later and lasted longer than was assumed earlier. Biological proxies indicate quasi-cyclic variability and shifts from brackish to freshwater conditions throughout the studied interval. Rybachya core was obtained from the early Khvalynian deposits. The Mangyshlak flow formed the depression and eroded the late Khvalynian deposits, which we did not observe in the core structure. It possibly collapsed into paleodepression and acted as a host material for the freshwater lentic faunal association. During the Holocene, we detected a transition from a tranquil water regime to a more dynamic one during the paleovalley gradual filling, followed by marine conditions typical for the modern Caspian Sea. |
| first_indexed | 2024-03-11T08:56:40Z |
| format | Article |
| id | doaj.art-2cfd3aa4cff24edbbc33380f4165f4e1 |
| institution | Directory Open Access Journal |
| issn | 1424-2818 |
| language | English |
| last_indexed | 2024-03-11T08:56:40Z |
| publishDate | 2023-01-01 |
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| spelling | doaj.art-2cfd3aa4cff24edbbc33380f4165f4e12023-11-16T20:03:45ZengMDPI AGDiversity1424-28182023-01-0115215010.3390/d15020150Multidisciplinary Study of the Rybachya Core in the North Caspian Sea during the HoloceneAlina Berdnikova0Elena Lysenko1Radik Makshaev2Maria Zenina3Tamara Yanina4Paleogeography Laboratory of Recent and Pleistocene Sediments, Faculty of Geography, Lomonosov Moscow State University, 119991 Moscow, RussiaPaleogeography Laboratory of Recent and Pleistocene Sediments, Faculty of Geography, Lomonosov Moscow State University, 119991 Moscow, RussiaPaleogeography Laboratory of Recent and Pleistocene Sediments, Faculty of Geography, Lomonosov Moscow State University, 119991 Moscow, RussiaP.P. Shirshov Institute of Oceanology, Russian Academy of Science, 117997 Moscow, RussiaPaleogeography Laboratory of Recent and Pleistocene Sediments, Faculty of Geography, Lomonosov Moscow State University, 119991 Moscow, RussiaMollusk fauna is an important component of the Caspian Sea ecosystem alongside ostracods and diatoms. These faunal proxies are essential indicators of hydrological shifts reflecting global and regional climate changes. Adding lithological, geochemical, and geochronological (radiocarbon) data, we revealed paleogeographic events of different scales recorded in the sequence of the Rybachya core from the North Caspian Sea. Here, we present the reconstruction of Mangyshlak paleovalley sediments during the Holocene multi-stage Neocaspian transgression, reflecting global and regional climate changes varying in scale and direction. The determined age of paleovalley-fill sediments, 8070 ± 110 cal yr BP and 7020 ± 140 cal yr BP, suggests that sedimentation processes with extended warming and humidification started later and lasted longer than was assumed earlier. Biological proxies indicate quasi-cyclic variability and shifts from brackish to freshwater conditions throughout the studied interval. Rybachya core was obtained from the early Khvalynian deposits. The Mangyshlak flow formed the depression and eroded the late Khvalynian deposits, which we did not observe in the core structure. It possibly collapsed into paleodepression and acted as a host material for the freshwater lentic faunal association. During the Holocene, we detected a transition from a tranquil water regime to a more dynamic one during the paleovalley gradual filling, followed by marine conditions typical for the modern Caspian Sea.https://www.mdpi.com/1424-2818/15/2/150paleovalleyCaspian SeaHoloceneNeocaspianMangyshlakmollusk fauna |
| spellingShingle | Alina Berdnikova Elena Lysenko Radik Makshaev Maria Zenina Tamara Yanina Multidisciplinary Study of the Rybachya Core in the North Caspian Sea during the Holocene Diversity paleovalley Caspian Sea Holocene Neocaspian Mangyshlak mollusk fauna |
| title | Multidisciplinary Study of the Rybachya Core in the North Caspian Sea during the Holocene |
| title_full | Multidisciplinary Study of the Rybachya Core in the North Caspian Sea during the Holocene |
| title_fullStr | Multidisciplinary Study of the Rybachya Core in the North Caspian Sea during the Holocene |
| title_full_unstemmed | Multidisciplinary Study of the Rybachya Core in the North Caspian Sea during the Holocene |
| title_short | Multidisciplinary Study of the Rybachya Core in the North Caspian Sea during the Holocene |
| title_sort | multidisciplinary study of the rybachya core in the north caspian sea during the holocene |
| topic | paleovalley Caspian Sea Holocene Neocaspian Mangyshlak mollusk fauna |
| url | https://www.mdpi.com/1424-2818/15/2/150 |
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