On the palaeoclimatic structure of MIS-5 analogues in the midland part of Siberia (palaeobotanical and U/Th dating data)

• Published in: Geologija
• Main Authors: Laukhin, Stanislav, Gaigalas, Algirdas-Juozapas
• Format: Article in Journal/Newspaper
• Language: Russian; Lithuanian; English
• Published: 2008
• Subjects: Kazantsovian time; Palaeoclimate; U/Th dating; Siberia; Macroflora; Palynospectra; Vegetation zonality; Greenland; Midland; ice core
• Online Access: http://vu.lvb.lt/VU:ELABAPDB4027453&prefLang=en_US

A simultaneous use of 14C, U/Th dating and palaeobotanic researches of the midland part of Western and Middle Siberia (Shurishkary, Gornaya Subbota, Golden Cape, Chembakchino and Bedoba) has allowed to trace a correlation of the palaeoclimatic events detected in these sections with similar events fixed in the ice-core of Greenland (SUMMIT) and MIS-5. The broad confidence intervals of U/Th dates do not allow precisely to date the detected palaeoclimatic events, but allow to establish a clear sequence and amplitudes of these events similar to records in the ice-core of Greenland and MIS-5. In the buried peat bogs of midland sections located about 60° NL and to the north, it is possible to detect analogous climatic events 5e5, 5e1, 5e4, 5c, 5d and to select tracks of events 5e3, 5e2. The main the optimum of the Kazantsovian Interglacial, as well as in the curve of the ice-core of Greenland (SUMMIT), falls in the very outset beginning of MIS-5 (5e5). The temporal inadequacy of palaeoclimatic events detected in peat bogs to analogous events of MIS-5 and the curve of the ice-core of Greenland is selected: the analogous events on the continent are usually exhibited earlier than in the ocean (MIS-5). Such a ratio from MIS-5 is known also for palaeoclimatic events dated by U/Th in the bottom deposits of Baikal. However, because of large confidence intervals of U/Th dates in peat bogs, no reliable regularity in the ratio of the time of development of palaeoclimatic events of MIS-5 and analogous events inside the continent has been traced.