Surface runoff to the Black Sea from the East European Plain during Last Glacial Maximum–Late Glacial time

Author(s):  
Aleksey Yu. Sidorchuk ◽  
Andrey V. Panin ◽  
Olga K. Borisova
2020 ◽  
Author(s):  
Andrei Briceag ◽  
Gabriel Ion ◽  
Mihaela Melinte-Dobrinescu ◽  
Dan Vasiliu ◽  
Naliana Lupascu

<p>The Danube Deep-Sea Fan, situated in NW Black Sea, is one of the most developed deep-sea sedimentary structures in Europe (Panin & Jipa, 2002). In 2018, in the framework of the uBiogas Project (24PCCDI/2018), several cores were acquired from the aforementioned area. In this study, high resolution microfaunal analyses coupled with sedimentological and geochemical ones, were performed on two gravity cores that revealed changes since the Last Glacial Maximum. The cores have been collected from two secondary canyons, situated in the E of the Danube Canyon, at 655,7 m (MN183_3_GC_1) and 1315 m water depths (MN183_8_GC_1). In both cores, three stratigraphic units as described by Ross & Degens (1974) were identified (oldest first): Unit 3 (Lacustrine lutite), Unit 2 (Sapropel Mud) and Unit 1 (Coccolith Mud).</p><p>The sediments of Unit 3 correspond to the Last Glacial Maximum and are marked by the presence of the cold-water ostracod species. The cores contain a reddish-brown clay and silty interval belonging to the post-glacial melt-water pulse of the Heinrich Event 1. In these deposits the ostracod assemblages display a high diversity and abundance. The CaCO<sub>3</sub> amount is very low, i.e. below 15%, except for the upper part where it reaches more than 50%. The samples of Unit 3 contain nannofossil assemblages that are entirely composed of reworked species from Cretaceous, Paleogene, Early and Middle Miocene intervals.</p><p>In Unit 2 (the sapropel), very few specimens of ostracods were identified, towards the top. During this depositional interval CaCO<sub>3 </sub>values are dropping again below 15%. The high abundance of the calcareous nannoplankton species Braarudosphaera bigelowii in the upper part of Unit 2 suggests the first strong influx of marine waters into the Black Sea basin.</p><p>In the youngest Unit 1, a brackish-marine ostracod assemblage, with low diversity and abundance was identified. This interval is characterized by the presence of polyhaline ostracods with Mediterranean origin. The ostracods from this assemblage tolerate salinities comprised between 17-21 ‰ and characterize a sub-littoral environment. The CaCO<sub>3</sub> values are increasing to more than 50%. During the depositional interval of Unit 1 the environmental was definitely a marine one, probably with a constant salinity of surface waters over 17 ppm, allowing the calcareous nannoplankton species Emiliania huxleyi and Braarudosphaera bigelowii to proliferate. The great abundance of the two taxa and especially of Emiliania huxleyi indicates the existence in the basin of a high nutrient input.</p><p>The financial support for this paper was provided by the Romanian Ministry of Research and Innovation, through the Programme 1 – Development of the National System of Research – Institutional Performance, Project of Excellence in Research-Innovation, Contract No. 8PFE/2018 and by the Project uBiogas, contract no. 24PCCDI/ 2018.</p><p> </p><p>Panin, N., Jipa, D., 2002. Danube river sediment input and its interaction with the northwestern Black Sea. Estuarine Coastline Shelf Science 54: 551–562.</p><p>Ross, D.A., Degens, E.T., 1974. Recent sediments of the Black Sea. In: Degens E.T. and Ross D.A. (Eds.), The Black Sea: Geology, Chemistry, and Biology. American Association of Petroleum Geologists, Tulsa, USA: 183–199.</p>


2020 ◽  
Vol 37 (4) ◽  
pp. 82-93
Author(s):  
L. Demay ◽  
P. M. Vasyliev ◽  
L. V. Koulakovska ◽  
D. V. Stupak ◽  
P. S. Shydlovskyi ◽  
...  

The first part of the Upper Pleniglacial (around 26000—20000 BP) is characterized by a deterioration in weather conditions, which reached its peak during the Last Glacial Maximum. In the East European Plain, most of its lands were dominated by a periglacial steppe-tundra with the maximum extension of ice sheet in the North and permafrost. The different animal species had to adapt to these environments, also as human groups.The recent works realized in Ukraine permit to better understand the lifestyles of the Palaeolithic human groups, particularly their subsistence activities, the modalities of settlements and the technocultural practices. We based our study on the main sites, Dorochivtsy III, Galich 1, Klussy, Korman, Molodova V, Obollonia, Oselivka, Pushkari 1 and Pogon (Pushkari 8). These sites are very important to better understand the human occupations for all the East European Plain. Here we particularly focus on the zooarchaeological remains, which permitted to better determine the taphonomic conditions, the human activities, the seasonality of occupations and the human and other animal relationships. The main species present in archaeological sites are Mammoth, Reindeer, Horse, Fox and Wolf, who have important implication on the territory modification and the food resource for humans. Moreover the animal eco-ethology involvement of their acquisition-exploitation by nomadic hunter-gatherers, permits to highlight the potential human behavioral strategies. They show the continuous occupation of the territories by humans, in any seasons, with the persistence of organized activities, innovations and varied behaviors. This period corresponds to the changes between middle Gravettian and late Gravettian, then first Epigravettian features. The end of the Last Glacial Maximum peak marks the disappearance of Late Gravettian and of human populations between 19—16000 BP, followed by a hiatus until 16000 BP.


2021 ◽  
Author(s):  
Brent Goehring ◽  
Brian Menounos ◽  
Gerald Osbron ◽  
Adam Hawkins ◽  
Brent Ward

Abstract. We present a new in situ produced cosmogenic beryllium-10 and carbon-14 nuclide chronology from two sets (outer and inner) of alpine glacier moraines from the Grey Hunter massif of southern Yukon Territory, Canada. The chronology potential of moraines deposited by alpine glaciers outside the limits of the Last Glacial Maximum (LGM) ice sheets potentially provide a less-ambiguous archive of mass balance, and hence climate than can be inferred from the extents of ice sheets themselves. Results for both nuclides are inconclusive for the outer moraines, with evidence for pre-LGM deposition (beryllium-10) and Holocene deposition (carbon-14). Beryllium-10 results from the inner moraine are suggestive of canonical LGM deposition, but with relatively high scatter. Conversely, in situ carbon-14 results from the inner moraines are tightly clustered and suggestive of terminal Younger Dryas deposition. We explore plausible scenarios leading to the observed differences between nuclides and find that the most parsimonious explanation for the outer moraines is that of pre-LGM deposition, but many of the sampled boulder surfaces were not exhumed from within the moraine until the Holocene. Our results thus imply that the inner and outer moraines sampled pre- and post-date the canonical LGM and that moraines dating to the LGM are lacking likely due to overriding by the subsequent Late Glacial/earliest Holocene advance.


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