Home – Home – Jornals – Russian Geology and Geophysics 2018 number Неопубликованное

A continuous record of paleogeographic events of the Holocene has been reconstructed based on biostratigraphic study and radiocarbon dating of the coastal peat bog in Nerpichy Bay, Sea of Okhotsk. Development of zonal landscapes since the end of the Late Pleistocene began from shrub forest-tundra to birch elfin forest with the first manifestations of broad-leaved trees in the early Holocene, dominance of dark coniferous taiga with maximum participation of broad-leaved trees in the middle Holocene, their further reduction in the late Holocena and almost complete disappearance in our time. On the coast peat accumulation began with an increase in temperatures about 10.2 ka cal. BP. A feature of the bog ecosystem development was the rapid change of the swampy larch forest after large-scale fires to a community dominated by green mosses, and then to shrub-grass-sphagnum phytocenoses. Further successions occurred with a gradual replacement of eutrophic-mesotrophic sphagnum mosses by oligotrophic Sphagnum fuscum, for which the highest rates of peat accumulation were noted 7.2-6.1 ka cal. BP. In this time the average annual temperature was approximately 2° C higher than today, and the long-term average annual precipitation was approximately 40 mm higher than at present. The most pronounced cooling periods in the Holocene occurred 10.6-10.2, 9.2-8.9, 8.3-8.0, 5.2-4.8, 4.3-4.0, 3.5-3.3, 2.8-2.5, 1.5-1.0 and 0.6-0.4 ka cal. BP. The cooling events identified in the southwestern Priokhotye region are consistent with the sequence of cold events of the Holocene both in the region and in the Northern Hemisphere.