scholarly journals STRATIGRAPHY OF BLANKET PEATLAND AND DEVELOPMENT OF ENVIRONMENTS OF THE BOLSHOY CHANTAR ISLAND IN THE LATE GLACIAL-HOLOCENE

2021 ◽  
Vol 40 (3) ◽  
pp. 85-102
Author(s):  
N.G. Razjigaeva ◽  
◽  
T.A. Grebennikova ◽  
L.A. Ganzey ◽  
V.V. Chakov ◽  
...  
Keyword(s):  
Sea Of Okhotsk ◽  
Late Glacial ◽  
Ice Age ◽  
Global Changes ◽  
Time Data ◽  
Radiocarbon Dates ◽  
Middle Holocene ◽  
The Sea Of Okhotsk ◽  
Anthropogenic Fires ◽  
Shantar Islands

Continued record of paleogeographic events in the Shantar islands since the end of the Pleistocene was restored on the basis of a multy-proxy study of the stratigraphy of the blanket peatland. Biostratigraphical studies included botanical, diatom and pollen analyses. The age-depth model was built using 7 radiocarbon dates. For the first time, data of the environment development were obtained for the coldest part of the Sea of Okhotsk. Synchronicity and metachronicity of paleoclimatic events with regional data and global changes have been established. The Younger Dryas on the Shantar islands was much colder than in other areas around the Sea of Okhotsk. The climate became more maritime after the isolation of the islands at the early-middle Holocene. The influence of the cold sea and the presence of drifting ice were one of the main factors, why the early and middle Holocene optimums were poorly manifested here, and also determined the specifics of climatic rhythm. Models explaining alternation of relatively warm and cold periods with different humidity are proposed. The age of periods with heavy snowfalls has been established, as evidenced by the change in the role of shrub pine in island vegetation. Phases of development of local swamp and zonal landscapes are highlighted. Spruce appeared on the area ~11410–10345 cal. yr. BP, when there was a landbridge, and spruce trees became common in the middle Holocene and especially at the boundary of the middle-late Holocene. One of the controlling factors for the development of swamp landscapes was thermokarst processes. Significant changes in the environment occurred in the Little Ice Age, the most severe conditions were ~500–260 cal. yr. BP. In the last 210 years, the most significant changes in landscapes have been associated with anthropogenic fires.

scholarly journals Bodengeographische Beobachtungen zur pleistozänen und holozänen Vergletscherung des Westlichen Tienshan (Usbekistan)

1996 ◽  
Vol 46 (1) ◽  
pp. 144-151
Author(s):  
Wolfgang Zech ◽  
Rupert Bäumler ◽  
Oksana Savoskul ◽  
Anatoli Ni ◽  
Maxim Petrov
Keyword(s):  
Little Ice Age ◽  
Late Glacial ◽  
Ice Age ◽  
Lower Side ◽  
Glacial Ice ◽  
Middle Holocene ◽  
Glacial Origin ◽  
Weathered Soils ◽  
Recent Origin ◽  
The Alps

Abstract. Soil geographic studies were carried out in the Oigaing valley between Ugamsky and Pskemsky range NE of Tashkent (W-Tienshan, Republic of Uzbekistan) with special regard to the Pleistocene and Holocene glaciation. Clear end moraines of the last main glaciation are preserved at the junction of Maidan and Oigaing river at 1500-1600 m a.s.l. They show intensively weathered soils with a depth of more than 80 cm. Similar deposits ol presumably Pleistocene or late glacial origin are also located upvalley at the embouchure of numerous side valleys (Beschtor, Tekesch, Aütor) into the main valley of Oigaing. All side valleys are characterized by late glacial ground and end moraines in 2500-2700 m a.s.l. showing intensively weathered brown colored soils of 30-40 cm depth. Further moraines of Holocene or recent origin are located approach of the recent glaciers which descend to 3000-3200 m. They show shallow, initial soils, and presumably correspond with glacial advances during the so-called "Little Ice Age" with a maximum advance at about 1850 in the Alps, and in the middle Holocene at about 2000 or 4000 a BP. Highly weathered, and rubefied interglacial soils developed from old Quaternary gravel are preserved above high glacial ice marginal grounds of the last main glaciation (>2850 m a.s.l.) in the lower side valley of the Barkrak river. In the upper valley huge drift could be shown above the ice marginal grounds, but without typical forms of morainic deposits. They give evidence for older glaciations with a greater extent compared with the last main glaciation. However, no corresponding moraines are present in the working area.

Late Glacial and Late Holocene Moraines in the Cerros Cuchpanga, Central Peru

1984 ◽  
Vol 21 (3) ◽  
pp. 275-285 ◽  
Author(s):  
H.E. Wright
Keyword(s):  
Little Ice Age ◽  
Late Holocene ◽  
Late Glacial ◽  
Ice Age ◽  
Recent Past ◽  
Valley Bottom ◽  
Radiocarbon Dates ◽  
Western Cordillera ◽  
Limestone Bedrock ◽  
Ice Field

Small ice fields on the western cordillera northeast of Lima were expanded to three times their present size in the recent past, and the regional snow line was probably about 100 m lower than it is today. Outwash from the expanded glaciers formed deltas of silt in valley-bottom lakes. When the ice lobes retreated, the reduced outwash was trapped behind recessional moraines, and the clear meltwater infiltrated into the limestone bedrock and emerged at the heads of the deltas in spring pools. The delta surfaces then became covered with peat, and radiocarbon dates for the base of the peat (1100 ± 70 and 430 ± 70 yr B.P. for two different deltas) indicate that the maximum ice advance was older than those dates and, thus, older than the Little Ice Age of many north-temperate regions. Much older moraines date from expansion of the same local summit glaciers to even lower levels in the main valleys, which had previously been inundated by the cordilleran ice field. The cordilleran deglaciation and this expansion of local glaciers probably occurred between 12,000 and 10,000 yr ago, on the basis of slightly contradictory radiocarbon dates.

Millennial-scale climatic and environmental oscillations in the Sea of Okhotsk in response to global changes during the last 190 Ka

2008 ◽  
Vol 423 (2) ◽  
pp. 1410-1413 ◽  
Author(s):  
S. A. Gorbarenko ◽  
N. Harada ◽  
M. I. Malakhov ◽  
Yu. P. Vasilenko ◽  
A. A. Bosin ◽  
...  
Keyword(s):  
Sea Of Okhotsk ◽  
Global Changes ◽  
The Sea Of Okhotsk ◽  
Millennial Scale

The Late Glacial human reoccupation of north-western Europe: new approaches to space-time modelling

Antiquity ◽  
2003 ◽  
Vol 77 (296) ◽  
pp. 232-240 ◽  
Author(s):  
Paul G. Blackwell ◽  
Caitlin E. Buck
Keyword(s):  
Bayesian Methods ◽  
Western Europe ◽  
Late Glacial ◽  
Ice Age ◽  
Northern Europe ◽  
Radiocarbon Dates ◽  
New Approaches ◽  
Last Ice Age ◽  
Upper Rhine ◽  
North Western

How and when was northern Europe reoccupied at the end of the last Ice Age? Radiocarbon dates from the earliest post-glacial contexts provide one answer: they offer a sequence in which the regions of Europe, from the Upper Rhine to Britain, saw the return of humans. The authors use Bayesian methods to model a chronology and thus arrive at a sequence with clear assessments of uncertainty.

THE INFLUENCE OF SEA ICE ON THE SEA COAST OF SHANTAR ISLANDS

2017 ◽  
Author(s):  
Margarita Illarionova ◽  
Margarita Illarionova
Keyword(s):  
Sea Ice ◽  
Land Surface ◽  
Sea Of Okhotsk ◽  
World Ocean ◽  
Tidal Currents ◽  
The Sea Of Okhotsk ◽  
The North ◽  
Ice Conditions ◽  
In The Beginning ◽  
Shantar Islands

The Shantar Islands is the group of islands satiated in the Sea of Okhotsk near the exit of Uda Bay, Tugur Bay and Ulban Bay. The islands separated from the mainland and started to exist only 6000 years ago. It happened under the influence of the sea transgression followed by flooding of some parts of the land surface and isolation of the most elevated mountain parts from the mainland. The climate of The Shantar Island is more severe than the climate in the North part of the Sea of Okhotsk due to its proximity to cold regions of Yakutia, complex system of wind and tidal currents, the duration of the ice period, loads of fog and frequent storm winds. The height of tides on the islands can reach 8 meters, and these tidal currents are considered as one of the fastest tides of the World Ocean. The ice near the islands appears in the beginning of November and doesn’t melt for 8-9 months, usually, till mid-July, but some years till mid-August. Such severe ice conditions cannot be observed anywhere else in the Sea of Okhotsk. The variety of forms of the Shantar Islands is a consequence of severe ice conditions, unusual tidal currents and irregularity of the seashore. The most important seashores forming factor is considered to be the activity of sea ice.

Lake sediment coring in South Greenland in 1999

2000 ◽  
pp. 60-64 ◽  
Author(s):  
Ole Bennike ◽  
Svante Björck
Keyword(s):  
Lake Sediments ◽  
Sea Level ◽  
Lake Sediment ◽  
Radiocarbon Dating ◽  
Late Glacial ◽  
High Elevation ◽  
Ice Age ◽  
Radiocarbon Dates ◽  
Last Ice Age ◽  
Sediment Coring

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Bennike, O., & Björck, S. (2000). Lake sediment coring in South Greenland in 1999. Geology of Greenland Survey Bulletin, 186, 60-64. https://doi.org/10.34194/ggub.v186.5216 _______________ The transition from the last ice age to the Holocene was a period of extremely rapid and large climatic changes (Björck et al. 1998). Because of this, the period has attracted much attention by Quaternary workers since these fluctuations were first demonstrated by Danish scientists (Hartz & Milthers 1901; Iversen 1934, 1954). In the ice-free parts of Greenland, many attempts have been made over the past few decades to find sediments from this transitional period. Some radiocarbon dates on marine molluscs from the late-glacial have been published, but most are based on conventional dating of several shells that might represent a mixture of Holocene and interglacial material. Conventional radiocarbon dating of lake sediments has also produced a number of ‘late-glacial’ dates, but where checked by accelerator mass spectrometry (AMS) radiocarbon dating, the sediments have proved to be Holocene (Björck et al. 1994a, b). These sediments contain ‘old carbon’ in the form of coal fragments and reworked interglacial organic detritus. In 1999 we tried a new approach to locate late-glacial lake sediments in Greenland. In southernmost Greenland, the shelf is narrow and the land area relatively small. Therefore the amount of glacierization during the Quaternary glacial stages must have been limited. In addition, this region is situated so far south in the North Atlantic that it must have been much influenced by the warming at 14,700 GRIP years BP (Björck et al. 1998). The southern location also means that the temperature conditions would allow a fairly rich plant and animal life to have become established rather early after recession of the ice. Sediment records from lakes located near sea-level at some distance from the outer coast extend back to the earliest Holocene (Fredskild 1973). Lakes situated at higher elevations might have become deglaciated earlier, when the Inland Ice thinned over the coast towards the end of the last ice age. Thus, in the 1999 programme we have sampled high-elevation basins, situated at 350–720 m above sea level (see Table 1). Basins situated in cirque valleys were avoided because it is possible that glaciers would have been present in such basins during the Little Ice Age. However, it turned out that most of the high-elevation basins investigated were devoid of sediments. Even at water depths over several tens of metres, the bottom consisted of stones and boulders and a good sedimentary sequence was only found in a single lake. For this reason, low-elevation basins as far away as possible from the present ice margin were also cored. In addition, it was decided to core a series of isolation basins at different elevations below the marine limit in order to establish a securely constrained curve for the relative shore-level change after the last deglaciation. Many such curves have been published from different parts of Greenland, but they are mainly based on mollusc shell dates which are much more uncertain than dates from isolation basins. The dated molluscs lived at various depths below sea-level and their relationship to the former sea-level is always uncertain. The locations of the cored basins are shown in Fig. 1 and short notes on the lakes are given in Table 1. This work is a continuation of the studies of recent years on lake sediments in South and West Greenland by the Geological Survey of Denmark and Greenland (Anderson & Bennike 1997; Overpeck et al. 1998; Anderson et al. 1999; 2000, this volume; Bennike 2000; Brodersen & Anderson 2000, this volume).

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