Место издания:Dipartimento di Scienze della Terra, Università di Pisa, Italia Pisa
Первая страница:50
Последняя страница:50
Аннотация:The cores of sediments and bottom samples fat 81 stations were collected during field campaign ofVNIIOkeangeologiya within the framework of the “Program for State Geological Mapping of the Territory and Continental Shelf of the Russian Federation” in September – October of 2020 (Gusev et al., 2020). The surface sample for pollen analysis was carried out on each station. The cores with total thickness more than 50 cm were obtained with variable interval (4-10 cm). This report is presented detail pollen records from core located in paleovalley of Indigirka River.The core MS-2036 (75°24’02,14” N, 167°07’02,20” E) with total thickness about 1.2 m was carried outfrom 65 m depth. The 28 samples were analyzed. The 20 pollen, spores and non-pollen palynomorph taxa were identified. The Lycopodium tablets were used to permit estimation of pollen concentrations (Stockmarr, 1971).Three pollen zones were distinguished according to changes in pollen spectra. The first zone (PZ-1) from 1.2 m to 0.5 m characterized by domination pollen of Betula (25%), Alnaster (7-15%), Salix (5-15%) in shrub taxa and Cyperaceae (20-25%), Poaceae (17%) in herbs. Pollen of Artemisia and Ericaceae are also present. The pollen concentration varies between 1000 and 2500 pollen grains g-1. The second zone (PZ-2) from 0.5 m to 0.12 m shows domination of herbs pollen taxa (65-70%). Cyperaceae and Poaceae is prevailed in this group.Pollen concentration decrease to 600-1000 grains g-1. The third zone (PZ-3) from 0.12 m to surface shows low concentrations of microfossils (250 pollen grains g-1). The single grains of pollen and spores were identified.The PZ-1 – PZ-2 boarder have a good correlation with disappearance of mollusk shells. The Portlandia arctica (Gray), Hiatella arctica (Linnaeus) and few another types were identified from 0.9 m to 0.46 m. The pollen records from excavated sediments may reflect vegetation signal from arctic and typical tundra conditions.The pollen spectra from PZ-1 matches well with Holocene pollen spectra from Bolshoy Lyahovsky island (Andreev et al., 2011).