The paper presents the results for the 14C dating obtained recently in the Laboratory of the Institute of Geology, Ufa Science Centre, Russian Academy of Science, on the basis of megafaunal bones, peats, wood and mollusk shells. Dates are reported in stratigraphic sequence from the Late Würmian to the Holocene.

We used a continuous krypton ion laser to rapidly oxidize milligram-sized fragments of coniferous driftwood of known ages, and dated the resulting carbon dioxide by accelerator mass spectrometry (AMS). AMS 14C ages of non-pretreated young wood from different parts of two logs were within 10% of the ages of conventionally determined alkaline insoluble fractions. The age of the oldest whole wood measured after laser oxidation was within the error ranges of conventional values.

Variations in atmospheric 14C content complicate the conversion of conventional 14C ages BP (i.e., years before AD 1950) into real calendar ages (AD/BC) (de Vries 1958; Willis, Tauber & Münnich 1960). These variations are indirectly observed in tree rings from European and North American wood. In recent decades, measurements made on dendrochronologically dated wood have resulted in the generally accepted Stuiver and Pearson calibration curves. These curves, together with other calibration data, were published in the first Radiocarbon Calibration Issue (Stuiver & Kra 1986), and are extended in the present Calibration Issue (Stuiver, Long & Kra 1993).

I suggest, on the basis of a statistical analysis, that recently determined “conventional radiocarbon ages” of Dead Sea Scroll documents are offset systematically by about +40 yr, leading to a similar overestimate of the ages of these documents. Much closer agreement with paleographic and specific dates is obtained when a correction of this magnitude is made to the “conventional 14C” values. This indicates that 14C dates may convey more precise information about the ages of these documents than initially recognized.

We present here a description of the 14C dating method used at the Institute of Geology, Estonian Academy of Science. We discuss results of geochronological studies of several stratigraphic sections, from which we estimate the age of the Late Weichselian (Late Valdaian) glacial maximum. 14C and paleobotanical data indicate that biodetrital materials comprise organic debris from various sources and suggest only a maximum age of investigated strata (16,000 BP).

The few studies of the paleogeography of the Ukrainian Carpathians include the chronology of relief formation (Demeduke 1971), the development of vegetation (Malinovsky 1980) and the formation of the landscape (Miller 1961). Previous paleographic inferences were based on comparisons with natural alpine cycles (Koziy 1950, 1963; Tsys 1955, 1968; Tretyak and Kuleshko 1982). Neighboring areas to the west and south of the Ukrainian Carpathians are also insufficiently studied (Serebrany 1978).

The transformation of radiocarbon years to calendar years (cal AD/BC) is not straightforward because of past variations in atmospheric 14C content (de Vries 1958; Suess 1970). A calibration curve, y = f(x), transforms each dendrochronologically dated calendar age (x) to a 14C date (y). By inverting this relationship, one can determine the calibrated calendar age of a given sample. In some time intervals, the calibration curve is problematic in that f(x) is not uniquely invertible (Fig. 1); even an exact measurement of y cannot be converted to a single calendar age (see examples in van der Plicht & Mook (1987)).

We discuss results of 14C dates obtained from areas of young volcanoes in Kamchatka. We apply these dates to reconstructing regional volcanic activity during the Holocene.

The use of radiocarbon dating in geocryological investigations makes it possible to establish a chronology for permafrost-geological development during the Late Pleistocene. Both global and regional time scales for the formation of Late Pleistocene permafrost have been worked out over the past 15–20 years at the Permafrost Institute of the Siberian Branch of the Russian Academy of Sciences. I present here results from study areas of northwestern Siberia and of North, Central and West Yakutia.

A reliable archaelogical chronology for medieval sites in northwestern Russia depends in part on a refined regional calibration scale for 14C dates. We present results of dates on tree-ring series from Novgorod that show a systematic discrepancy from European calibration curves, and that underline the need for more extensive 14C dating as the basis of an extended calibration curve for the region.

We report 172 dates on osseous material from Paleolithic sites of the East European Plain.

In this paper we consider the radiocarbon chronology of Mesolithic and Neolithic settlement sites in the eastern Baltic region. Dating of wood and charcoal from Estonian and Latvian sites establishes the periods (early, middle and late) within these epochs. We present 90 14C dates, as yet unpublished in radiocarbon, produced by laboratories in Riga, Tallin, Tartu, Leningrad and Moscow.