Six palsa mire in Usa River valley and in Vorkuta area in North-eastern part of European Russia were studied in detail. In total 75 new ¹⁴C dates from different palsa sections were obtained. In palsa mire near Bugry Settlement 3.2 m high palsa dated from 8.6 to 2.1 ka BP. The permafrost and palsa began 2.1 ka BP. In palsa mire near Usa Settlement low moor peat in 2 m high palsa dated 3690 BP, palsa began to heave at least 3700 BP. A low-moor peat of 2.5 m high palsa indicates the change in the hydrological-mineral regime during 7.1 to 6.3 ka BP, heaving commenced 6 ka BP. A number of 8 ¹⁴C dates from 5.6 to 2.7 ka BP obtained from peat of 3 m high palsa. Near Abez' Settlement palsa development began about 2.8 ka BP. There are both large and smaller palsas. Low-moor peat of 3.5 m high palsa is dated between 9180 BP to 6730 BP near Nikita Settlement. In Vorkuta area near Khanovey Settlement the northern most palsa is found. The ¹⁴C age of peat at slope of the palsa is much younger, than in an axial part, there is inversion of the dates: the date 3.5 ka BP is between dates 2.9 and 2.8 ka BP. It is probably caused by creep of peat downwards from a summit. This evidenced this frozen mound is real palsa, but not a residual form as a result of erosion.

Data was submitted and proofread by Yurij K Vasil'chuk and Lyubov Bludushkina at the faculty of Geography, department of Geochemistry of Landscapes and Geography of Soils, Lomonosov Moscow State University.