L. D. Sulerzhitsky

Holocene History of the Northern Range Limits of Some Trees and Shrubs in Russia

Nearly 280 radiocarbon-dated macrofossils from 115 sites in Russia are used to reconstruct the shift in the northern treeline during last 10,000 yr, which was primarily considered to be climatically controlled. Picea obovata Ledeb. spread

Late Pleistocene‐Holocene Volcanism on the Kamchatka Peninsula, Northwest Pacific Region

Late Pleistocene-Holocene volcanism in Kamchatka results from the subduction of the Pacific Plate under the peninsula and forms three volcanic belts arranged in en echelon manner from southeast to northwest. The cross-arc extent of recent volcanism exceeds 250 km and is one of the widest worldwide. All the belts are dominated by mafic rocks. Eruptives with SiO 2 >57% constitute ∼25% of the most productive Central Kamchatka Depression belt and ∼30b% of the Eastern volcanic front, but <10% of the least productive Sredinny Range belt. All the Kamchatka volcanic rocks exhibit typical arc-type signatures and are represented by basalt-rhyolite series differing in alkalis. Typical Kamchatka arc basalts display a strong increase in LILE, LREE and HFSE from the front to the back-arc. La/Yb and Nb/Zr increase from the arc front to the back arc while B/Li and As, Sb, B, Cl and S concentrations decrease. The initial mantle source below Kamchatka ranges from N-MORB-like in the volcanic front and Central Kamchatka Depression to more enriched in the back arc. Rocks from the Central Kamchatka Depression range in 87 Sr/ 86 Sr ratios from 0.70334 to 0.70366, but have almost constant Nd isotopic ratios ( 143 Nd/ 144 Nd 0.51307-0.51312). This correlates with the highest U/Th ratios in these rocks and suggest the highest fluid-flux in the source region. Holocene large eruptions and eruptive histories of individual Holocene volcanoes have been studied with the help of tephrochronology and 14 C dating that permits analysis of time-space patterns of volcanic activity, evolution of the erupted products, and volcanic hazards.

Vegetation and climate history of the Yana River lowland, Russia, during the last 6400 yr

New pollen records and radiocarbon dates from two sites in the Yana River lowlands, Arctic Yakutia, Russia provide reconstructions of vegetation and climate history of this region during the last 6400 yr. The #uctuations in pollen and spores re#ect the local hydrological events and regional climate changes. The data show that larch (Larix dahurica) forests with shrub alder (Alnus fruticosa) and dwarf birch (Betula exilis) dominated the area during the last 6400 yr BP. There is no evidence for tree-line #uctuations at the sites during the latter half of the Holocene. Climate reconstructions made by transfer function from one site show that the warmest time was between 6000 and 4500 yr BP. All climate #uctuations reconstructed at this site correspond well with regional climate changes. ( 2000 Elsevier Science Ltd. All rights reserved.

Holocene Eruptive History of Shiveluch Volcano, Kamchatka Peninsula, Russia

The Holocene eruptive history of Shiveluch volcano, Kamchatka Peninsula, has been reconstructed using geologic mapping, tephrochronology, radiocarbon dating, XRF and microprobe analyses. Eruptions of Shiveluch during the Holocene have occurred with irregular repose times alternating between periods of explosive activity and dome growth. The most intense volcanism, with frequent large and moderate eruptions occurred around 6500-6400 BC, 2250-2000 BC, and 50-650 AD, coincides with the all-Kamchatka peaks of volcanic activity. The current active period started around 900 BC; since then the large and moderate eruptions has been following each other in 50-400 yrs-long intervals. This persistent strong activity can be matched only by the early Holocene one. Most Shiveluch eruptions during the Holocene produced medium-K, hornblende-bearing andesitic material characterized by high MgO (2.3-6.8 wt %), Cr (47-520 ppm), Ni (18-106 ppm) and Sr (471-615 ppm), and low Y ( 2.5 km 3 of tephra. More than 10 debris avalanches took place only in the second half of the Holocene. Extent of Shiveluch tephra falls exceeded 350 km; travel distance of pyroclastic density currents was >22 km, and that of the debris avalanches ≤20 km.

Late Pleistocene Interstadial Environment on Faddeyevskiy Island, East-Siberian Sea, Russia

Pollen, plant macrofossil, loss-on-ignition and radiocarbon analyses of a 1.4-m section in thermokarst topography from Faddeyevskiy Island (75°20′N, 143°50′E, 30 m elevation) provides new information on Late Pleistocene interstadial environmental history of this high Arctic region. Conventional radiocarbon dates (25,700 ± 1000, 32,780 ± 500, 35,200 ± 650 yr BP) and two AMS dates (29,950 ± 660 and 42,990 ± 1280 yr BP) indicate that the deposits accumulated during the Kargian (Boutellier) interval. Numerous mammoth (Mammuthus primigenius) remains that have been collected in vicinity of the site in this study were radiocarbon dated to 36,700-18,500 yr BP. Rare bison (Bison priscus) bones were dated to 32,200 ± 600 and 33,100 ± 320 yr BP. Poaceae, Cyperaceae, and Artemisia pollen dominate the spectra with some Ranunculaceae, Caryophyllaceae, Rosaceae, and Asteraceae. The pollen spectra reflect steppe-like (tundra-steppe) vegetation, which was dominant on the exposed shelf of the Arctic Ocean. Numerous Carex macrofossils suggest that the summer climate was at least 2°C warmer than today. The productivity of the local vegetation during the Kargian interstadial was high enough to feed the population of grazing mammals.

14C chronology of stone age cultures in the Russian Far East

Ca. 150 unequivocal (super 14) C dates from the prehistoric cultures in the Russian Far East can be used to elucidate chrono-cultural boundaries in that region. Microblade technology started as early as ca. 20,000 BP, and continued to exist in the middle Amur River basin until ca. 10,500 BP, and in Primorye until ca. 7800 BP. The emergence of pottery-making in the lower Amur River basin goes back to ca. 13,300 BP. The transition from Upper Paleolithic to Neolithic took place during the time interval 13,300-7800 BP and pottery was widely spread in the Russian Far East by ca. 6700-8400 BP. The first evidence of shellfish collection is estimated to ca. 6400 BP at Peter the Great Gulf coast, Sea of Japan. The beginning of agriculture in Primorye, based on finding of both millet seeds (Setaria italica L.) and pollen of cultivated cereals (Cerealia), is (super 14) C-dated to ca. 4200-3700 BP (ca. 1980-2900 cal BC). The Neolithic/Early Iron Age boundary was estimated at ca. 3100-3300 BP (1400-1600 cal BC) in the mainland Russian Far East, and to ca. 1800-2300 BP (400 cal BC-200 cal AD) on the Sakhalin and southern Kuril Islands.

Younger Dryas pollen records from Sverdrup Island (Kara Sea)

Abstract Sverdrup Island, in the Kara Sea, is currently occupied by polar desert vegetation. The analysis of Allerod deposits indicates a climate drier than presently, with increased summer and decreased winter temperatures. The relative scarcity of distal pollen indicates that mainland source areas were located further south than at present. Younger Dryas cooling and increased dryness resulted in an increase of the proportions of Artemisia, Chenopodiaceae and Salix pollen, and in the extent of Sphagnum mosses. Preboreal time was marked by warmer, more humid conditions, with dwarf birches, Ericales and possibly Alnus fruticosa. The increased proportions of distally-derived arboreal birch pollen, coupled with the local component of the assemblages, indicates that the early Holocene represented the climatic optimum, initiated by the opening of the Arctic Ocean. Subsequent climate fluctuations were muted on Sverdrup Island, due to the development of microclimatic conditions associated with an oceanic regime.

Radiocarbon Dating of Large Holocene Volcanic Events Within South Kamchatka (Russian Far East)

Radiocarbon dating is widely used when studying recent volcanic activity in the Kamchatka Peninsula due to the abundance of organic matter that is associated with the volcanic deposits. Here, we present the results of 14 C dating of major volcanic events within the active South Kamchatka volcanic zone. South Kamchatka includes 8 recently active volcanic centers (stratovolcanoes, calderas, and large craters) that have been erupting during the Holocene. Their tephras represent useful markers for both the southern part of the peninsula and the Northern Kurile Islands. Since these marker tephra layers facilitate stratigraphic and tephrochronological studies in this area, it was important to determine their ages. We have obtained 73 new individual 14 C dates on paleosol, peat, charcoal, and wood associated with the marker tephra layers, then complemented these data with 37 earlier published dates and analyzed the resulting data set. We selected the reliable dates and then obtained average 14 C ages of marker tephra layers. The details of these procedures, as well as brief descriptions of South Kamchatka Holocene eruptions and their tephra beds, are presented in the paper.

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

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 other 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.

The early history of Moscow : 14C dates from red square

For the first time, a series of (super 14) C dates has been obtained for samples from the archaeological excavations in Red Square, the historical center of Moscow. The remains of burned dwellings from the bottom of the cultural layer were dated as well as dispersed charcoal from the underlying plough soil. The results correspond to a 200-yr time interval and prove that arable activity at the site began as early as the late 11th century AD. The field belonged to Moscow itself or to rural settlements nearby. The oldest dwelling was built ca. the late 12th-early 13th century AD.