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The North Dvina river delta development over the Holocene: geochronology and palaeoenvironment

Zaretskaya N. E., Shevchenko N. V., Simakova A. N., Sulerzhitsky L. D.

Geochronometria

2011

Vol. 38, no. 2

116-127

In this paper, a detailed overview of the Holocene evolution of the North Dvina river (ND) delta (southern White Sea) is presented; it is based on radiocarbon dating, geomorphological and oth-er field surveys, and plant macrofossil and palynological data. We have identified three main stages of the delta evolution: estuary erosional (Allerød – 5700 cal BC), lagoon or tidal-marsh (5700 cal BC – 3700 cal BC) and fan-delta accumulative (3700 cal BC – present). These stages are correlated with local climatic curves, sea level changes, glacioisostatic raise curve and Baltic Sea stages. A variety of landforms has been identified and dated within the delta. These results help to explain the spatial and temporal patterns in the prehistoric human occupation of this area.

Radiocarbon dating of the Kurile Lake caldera eruption (South Kamchatka, Russia)

Zaretskaia N. E., Ponomareva V. V., Sulerzhitsky L. D., Dirksen O. V.

Geochronometria

2001

Vol. 20

95-102

In this paper the set of radiocarbon dates obtained for the caldera-forming early-Holocene Kurile Lake eruption, which deposited a very important key-marker ash (KO) and formed the isochronous benchmark, is analyzed. Previous 12 dates derived from samples collected mostly far from caldera, and fall into the significant time interval (7890-7530 BP). In 1996-98 we performed the extensive sampling of organic matter related to pyroclastic flow and fall KO deposits, and 17 new dates were obtained. We selected the valid dates from both data sets analyzing the sample types and taphonomy, to estimate the accurate age of the KO eruption, and sharpened the time-span (7690-7530 BP) where the reliable dates fall. The estimated age is 7618š14 BP (Cal. 6455 BC).