Two lake and bog sediments have been thoroughly studied using palynological and radiocarbon dating methods. These are the Lembolovskoye Lake section located in the southern part of the Karelian Ithmus and the Mshinskoye bog section located in the southwestern part of the Leningrad province. The data obtained allow us to reconstruct the main features of the vegetation cover evolution, the chronology for the appearance and a real distribution of the main arboreal species from the south of the Leningrad province to the north, and to construct curves of the paleoclimate parameter changes for the area under study. Thirty-six 14C dates were obtained for the Lembolovskoye Lake section (7 m thick). According to those dates, the organic gyttja formation in the lake began 9870 ± 170 BP. Spore-pollen spectra with high percentage of herbs, arborescent, and shrub-birch dated back to the Younger Dryas were found out in clay layers at a depth of 6.5 m. An appearance of spruce and alder pollen is dated at 6860 ± 120 and 7510 ± 150 BP, respectively. The maximal percentage of broad-leaved species falls on the first half of the Atlantic (AT-1). Thirty-two dates were obtained for the Mshinskoye bog section (6 m thick): from 60 : 70 to 9520 ± 170 BP (the last date fixed the beginning of peat formation); 12 palinozones from the Preboreal to the Subatantic were recognized there. The spruce and alder pollen began to appear 7520 ±110 and 7670 ± 130 BP, respectively. The maximal amount of broad-leaved species is observed at 4690 ± 80 BP. The detailed reconstruction of changes in vegetation communities during the Late Glacial and Holocene was correlated with paleoclimatic characteristics, which have been recontructed for the sections under study by using the information from a statistical method of spore-pollen data processing.

ice-wedge ice indicates winter conditions colder than during the MIS3 interstadial and warmer than during MIS2 stadial, and similar atmospheric winter moisture sources as during the MIS2 stadial. Buchchagy Ice Complex pollen spectra reveal tundra-steppe vegetation and harsher summer conditions than during the MIS3 interstadial and rather similar vegetation as during the MIS2 stadial. Short-term climatic variability during MIS5 is reflected in the record. Even though the regional chronostratigraphic relationship of the Buchchagy Ice Complex to the Last Interglacial remains unclear because numerical dating is widely lacking, the present study indicates permafrost (Ice Complex) formation during MIS5 sensu lato, and its preservation afterwards. Palaeoenvironmental insights into past climate and the periglacial landscape dynamics of arctic lowlands in eastern Siberia are deduced from the record.

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A radiochemical study was carried out on massive sulfides from Semyenov hydrothermal district at the Mid-Atlantic Ridge. New and published results provide evidence that 230 Th/U ages obtained for massive sulfides are reliable. The sulfide deposits from the West, North-West, North-East, and East hydrothermal sites at the Semyenov hydrothermal district were formed between ~124 ka and ~37 ka ago. The hydrothermal activity might have started in the eastern part of the district and moved to the west by episodic ore formation.