TY - JOUR

T1 - The Records of Environmental Changes in Lacustrine–Swamp Sequences within the Mountain Area of Iturup Island since the Late Glacial Period

AU - Razjigaeva, N. G.

AU - Ganzey, L. A.

AU - Grebennikova, T. A.

AU - Mokhova, L. M.

AU - Degterev, A. V.

AU - Ezhkin, A. K.

AU - Rybin, A. V.

AU - Arslanov, Kh A.

AU - Maksimov, F. E.

AU - Petrov, A. Yu

N1 - Razjigaeva, N.G., Ganzey, L.A., Grebennikova, T.A. et al. The Records of Environmental Changes in Lacustrine–Swamp Sequences within the Mountain Area of Iturup Island since the Late Glacial Period. Russ. J. of Pac. Geol. 16, 116–130 (2022). https://doi.org/10.1134/S1819714022020087

PY - 2022/4

Y1 - 2022/4

N2 - Abstract: We have received unique material on the development of the natural environment for the last 12 400 cal. yr. BP in the central part of Iturup Island. High-resolution paleoreconstructions have been based on the multi-proxy study of paleolake sediments found on the plateau (height 400–420 m) located northwest of the Baransky Volcano. For the first time, a record of paleogeographic events has been obtained for the Late Glacial and the Early Holocene. The age model is based on nine radiocarbon dates. Diatom analysis has made it possible to distinguish 11 stages of lake–swamp evolution. The paleolake reached its maximum depth at ~9890–7900 cal. yr. BP and became extinct at 1400 cal. yr. BP. The vegetation development stages and the landscape change factors have been restored. The Younger Dryas cooling recorded in Iturup was characterized by humidity changes. The role of forest vegetation rapidly increased at the Pleistocene–Holocene boundary of ~11 470 cal. yr. BP under warmer climatic conditions. Distribution of dwarf pine as an indicator of stable snow cover has been analyzed. Dark-coniferous forests existed in the mountainous part of the island since the Late Glacial and were the most widespread in the Early Holocene. The onset of birch forest expansion at 6200 cal. yr. BP was related to the intensification of volcanic activity and frequent ash falls. A number of identified cold events were enhanced by the weakening of the warm Soya Current. The intensive transfer of allochthonous pollen from the southern Kuril Islands and the Japanese Islands at 3540 cal. yr. BP is a sign of cyclogenesis intensification in the Kuril Islands. The Holocene climatic rhythms in the landscape development of the Iturup mountains, as well as the influence of warm and cold currents and other regional factors, have been analyzed.

AB - Abstract: We have received unique material on the development of the natural environment for the last 12 400 cal. yr. BP in the central part of Iturup Island. High-resolution paleoreconstructions have been based on the multi-proxy study of paleolake sediments found on the plateau (height 400–420 m) located northwest of the Baransky Volcano. For the first time, a record of paleogeographic events has been obtained for the Late Glacial and the Early Holocene. The age model is based on nine radiocarbon dates. Diatom analysis has made it possible to distinguish 11 stages of lake–swamp evolution. The paleolake reached its maximum depth at ~9890–7900 cal. yr. BP and became extinct at 1400 cal. yr. BP. The vegetation development stages and the landscape change factors have been restored. The Younger Dryas cooling recorded in Iturup was characterized by humidity changes. The role of forest vegetation rapidly increased at the Pleistocene–Holocene boundary of ~11 470 cal. yr. BP under warmer climatic conditions. Distribution of dwarf pine as an indicator of stable snow cover has been analyzed. Dark-coniferous forests existed in the mountainous part of the island since the Late Glacial and were the most widespread in the Early Holocene. The onset of birch forest expansion at 6200 cal. yr. BP was related to the intensification of volcanic activity and frequent ash falls. A number of identified cold events were enhanced by the weakening of the warm Soya Current. The intensive transfer of allochthonous pollen from the southern Kuril Islands and the Japanese Islands at 3540 cal. yr. BP is a sign of cyclogenesis intensification in the Kuril Islands. The Holocene climatic rhythms in the landscape development of the Iturup mountains, as well as the influence of warm and cold currents and other regional factors, have been analyzed.

KW - climate changes

KW - cold events

KW - effects of volcanic ash precipitation

KW - high-resolution reconstructions

KW - Holocene

KW - Kuril Islands

KW - radiocarbon dating

KW - Younger Dryas

UR - http://www.scopus.com/inward/record.url?scp=85128035692&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/32c6f66d-66e3-3eb3-a2d9-933ad0fc85fa/

U2 - 10.1134/s1819714022020087

DO - 10.1134/s1819714022020087

M3 - Article

AN - SCOPUS:85128035692

VL - 16

SP - 116

EP - 130

JO - Russian Journal of Pacific Geology

JF - Russian Journal of Pacific Geology

SN - 1819-7140

IS - 2

ER -