Last interglacial environment of the Baikal Region (Southern Siberia, Russia) based on analysis of fossil invertebrates and plants

2021 ◽  
Vol 4 (6) ◽  
Author(s):  
S.A. KUZMINA ◽  
L.A. SAVELIEVA ◽  
S.S. POPOVA ◽  
F.E. MAKSIMOV ◽  
V.YU. KUZNETSOV ◽  
...  

New data on fossil insects, soil and freshwater invertebrates, plant macrofossils, pollen and spores were obtained from a problematic lower unit of the reference section Bely Yar-II (Tunka Rift, Baikal Region, Russia). The invertebrates show a natural succession from a small lake to a wetland; plant macrofossils confirm the early stages of succession. Pollen and spore data reflect a wide range of environments and vegetation from moderate climate supporting regional forests to relatively cold, dry parkland. New Uranium-Thorium data (99 ± 20 ka and 101 ± 13 ka), along with environmental reconstructions, indicate that the lower unit was probably formed during one of the cold sub-stages towards the end the last inter-glaciation (MIS5).

1992 ◽  
Vol 3 (4) ◽  
pp. 177-194 ◽  
Author(s):  
Lauri Kaila

The Elachistidae material collected during the joint Soviet-Finnish entomological expeditions to the Altai mountains, Baikal region and Tianshan mountains of the previous USSR is listed. Previous literature dealing with the Elachistidae in Central Asia is reviewed. A total of 40 species are dealt with, including descriptions of five new species: Stephensia jalmarella sp. n. (Altai), Elachista baikalica sp. n. (Baikal), E. talgarella sp. n. (southern Kazakhstan), E. esmeralda sp. n. (southern Kazakhstan) and E. filicornella sp. n. (southern Kazakhstan). The previously unknown females of E. bimaculata Parenti, 1981 and Biselachista zonulae Sruoga, 1992 are described.


1981 ◽  
Vol 16 (3) ◽  
pp. 293-321 ◽  
Author(s):  
Calvin J. Heusser

AbstractPollen and spores in stratigraphic sections located between 40 and 42°S range in age from the Holocene, through much of the Llanquihue Glaciation, to the last interglaciation. Chronology of the stratigraphy derives from some 35 14C ages and the age relations of Llanquihue Drift and related deposits. Q-Mode, rotated, principal-components analysis of four key pollen records covering the last interglacial-glacial cycle resulted in four leading components: Nothofagus dombeyi type, Gramineae, Weinmannia-Fitzroya type, and Myrtaceae. Analysis emphasizes interaction between the first two components. Loadings of Gramineae during the interglaciation are high, unlike the Holocene; Weinmannia-Fitzroya-type loadings, prominent in the Holocene, are negligible during the interglaciation. N. dombeyi type is the primary component during Llanquihue Glaciation; it becomes modified by increases of Gramineae sometime after 31,000 and before 14,000 yr B.P. and of Myrtaceae later. The Myrtaceae with Weinmannia-Fitzroya type also registers some activity around 42,000 yr B.P. Fluctuations in the belt of westerly winds, reflecting changing meteorological conditions in polar latitudes, are suggested by these data. With the belt located farther south than it is today, interglacial climate was much drier and warmer than during the Holocene; more northerly displacement of the belt obtained when climate was colder during Llanquihue Glaciation. Evidence from comparable latitudes in the Southern Hemisphere points toward a synchrony of major climatic events indicating harmonious fluctuations in the position of the westerlies.


Author(s):  
В.Ю. Данильченко ◽  
М.В. Зыцарь ◽  
Е.А. Маслова ◽  
М.С. Бады-Хоо ◽  
И.В. Морозов ◽  
...  

Мутации в гене SLC26A4 являются частой причиной потери слуха во многих регионах мира. В работе приводятся результаты молекулярно-генетического анализа (с использованием секвенирования по Сэнгеру) последовательности гена SLC26A4, впервые проведенного в выборке пациентов с потерей слуха неустановленной этиологии (n=232) из Республик Тыва и Алтай. Установлены контрастные различия патогенетического вклада мутаций в гене SLC26A4 в этиологию нарушения слуха у коренных жителей этих географически близких регионов: 28,2% - для тувинцев и 4,3% - для алтайцев. Выявлены как уже известные, так и новые патогенные варианты, а также широкий спектр полиморфных вариантов гена SLC26A4. Mutations in the SLC26A4 gene are a common cause of hearing loss in many regions of the world. This paper presents the results of molecular genetic analysis (by Sanger sequencing) of the SLC26A4 sequence, first performed in the sample of patients with hearing loss of unknown etiology (n=232) from the Tyva Republic and the Altai Republic. Contrast differences of the pathogenic contribution of SLC26A4 mutations to the etiology of hearing impairment were revealed in the indigenous peoples of these geographically close regions: 28.2% for Tuvinians and 4.3% for Altaians. Both known and novel pathogenic variants as well as a wide range of polymorphic variants were found in the SLC26A4 gene sequence.


<em>Abstract.</em>—Hudson riverine and coastal marshes provide a paleoecological archive consisting of information on climate and land use at both the local and watershed scales. The timing of formation of these marshes is documented using accelerator mass spectrometry (AMS) <sup>14</sup>C dating of identified plant macrofossils in basal marsh organic sediments. While the Staten Island marsh is oldest and dates to 11,000 years before present (BP), Piermont, Iona, and Croton marshes date to the mid-Holocene, and the Jamaica Bay marshes formed most recently. Pollen and spores, charcoal, and plant macrofossils in the marsh sediments document marked climatic shifts as well as anthropogenic impact in the region. Assessment of the inorganic and organic content of the sediments in the marshes reveals a pattern of decreasing inorganic supply with the arrival of the Europeans, possibly due to the construction of numerous Hudson River tributary dams. Piermont Marsh, because of its sensitive location in the Hudson River, records droughts and wet intervals through species which have specific salinity affinities. Throughout the marsh records, the ragweed <em>Ambrosia </em>pollen rise marks the anthropogenic impact at the landscape scale. The recorded changes in hydrology and salinity that occurred throughout the centuries and millennia would have had profound effects throughout the food web and estuarine ecosystem. Fish populations would have been affected by changes in the food supply due to shifts in runoff affecting turbidity and light penetration in the river. Local vegetation changes within marshes may also have affected juvenile fish populations.


2006 ◽  
Vol 143 (5) ◽  
pp. 609-620 ◽  
Author(s):  
M. BRÖCKER ◽  
L. FRANZ

This paper reports new geochronological data from the island of Andros, one of the less-studied islands of the Cycladic blueschist belt in the central Aegean Sea. On Andros, two tectonic units can be distinguished, the Makrotantalon unit and the Lower unit, which are separated by a low-angle normal fault, related to large-scale regional extension. Mineral assemblages indicate greenschist-facies P–T conditions for the last metamorphic overprint of both units. In contrast to the structurally lower unit, unambiguous indications for an earlier high-pressure stage were not recognized in rocks collected above the tectonic contact. Owing to a polyphase metamorphic evolution and incomplete resetting of the Rb–Sr isotope system during overprinting, phengite geochronology indicates a wide range in dates between c. 104 and 21 Ma for the Makrotantalon unit, as observed in rocks of similar structural position elsewhere in the Cyclades. The new Rb–Sr data support the interpretation, but are not conclusive evidence, that tectonic slices within the hanging wall were affected by two periods of Cretaceous metamorphism (c. 100–90 Ma and c. 80–70 Ma) and a Miocene event (c. 21 Ma). Tectonic juxtaposition was accomplished around c. 21 Ma. The Lower unit is correlative with the Cycladic high-pressure occurrences. Rb–Sr phengite dating yielded the same range in ages as determined elsewhere in the region for white mica of high-pressure rocks (c. 50–40 Ma) and their overprinted, greenschist-facies derivatives (c. 23–21 Ma). An age gradient towards the tectonic contact with the overlying Makrotantalon unit is not developed. The new results fit well into the previously established chronological framework for the larger study area. Indications for regional differences in the timing of the HP stage and/or the greenschist-facies overprint have not yet been found.


Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2287
Author(s):  
Natalia Malygina ◽  
Elena Mitrofanova ◽  
Natalia Kuryatnikova ◽  
Roman Biryukov ◽  
Dmitry Zolotov ◽  
...  

Microplastics (MPs) contaminations of freshwater and marine environments has become a global issue. Lakes in southern Siberia provide a wide range of ecosystem services and are essential elements in the annual and interannual runoff distribution of the Great Siberian Rivers. However, the extent of their MPs pollution remains unknown. In this paper, for the first time, we analyze the concentrations, composition, and spatial distribution of MPs in six lakes in southern Siberia. The studied lakes are located both in the Altai mountains and the West Siberian plain. Some of them are significantly impacted by human activities, while others are located in protected areas with no permanent population. Nevertheless, MPs were detected in all of the studied lakes. MPs concentrations ranged from 4 to 26 MPs L−1. Comparing with other inland lakes, South Siberian lakes presented moderate MPs concentrations. Among the registered MPs forms, fragments and films were dominant, with a size range between 31 and 60 nm. The MPs’ sources depend on local human activities (fishing, transport, landfilling). Therefore, sufficiently high concentrations were observed even in remote lakes. The present study set a baseline that emphasizes the need for increased attention to waste management and sustainable water use in Siberian freshwater environments.


2020 ◽  
Vol 16 (5) ◽  
pp. 1777-1805
Author(s):  
Josephine R. Brown ◽  
Chris M. Brierley ◽  
Soon-Il An ◽  
Maria-Vittoria Guarino ◽  
Samantha Stevenson ◽  
...  

Abstract. El Niño–Southern Oscillation (ENSO) is the strongest mode of interannual climate variability in the current climate, influencing ecosystems, agriculture, and weather systems across the globe, but future projections of ENSO frequency and amplitude remain highly uncertain. A comparison of changes in ENSO in a range of past and future climate simulations can provide insights into the sensitivity of ENSO to changes in the mean state, including changes in the seasonality of incoming solar radiation, global average temperatures, and spatial patterns of sea surface temperatures. As a comprehensive set of coupled model simulations is now available for both palaeoclimate time slices (the Last Glacial Maximum, mid-Holocene, and last interglacial) and idealised future warming scenarios (1 % per year CO2 increase, abrupt four-time CO2 increase), this allows a detailed evaluation of ENSO changes in this wide range of climates. Such a comparison can assist in constraining uncertainty in future projections, providing insights into model agreement and the sensitivity of ENSO to a range of factors. The majority of models simulate a consistent weakening of ENSO activity in the last interglacial and mid-Holocene experiments, and there is an ensemble mean reduction of variability in the western equatorial Pacific in the Last Glacial Maximum experiments. Changes in global temperature produce a weaker precipitation response to ENSO in the cold Last Glacial Maximum experiments and an enhanced precipitation response to ENSO in the warm increased CO2 experiments. No consistent relationship between changes in ENSO amplitude and annual cycle was identified across experiments.


1987 ◽  
Vol 28 (1) ◽  
pp. 157-174 ◽  
Author(s):  
Jerry J. Pilny ◽  
Alan V. Morgan

AbstractA stream section near Innerkip, Ontario, exposes several meters of organic silts and peaty detritus beneath two late Wisconsinan tills. Radiocarbon dates provide a minimal middle Wisconsinan age of >50,000 yr B.P. A 250-kg bulk sample from the peat stratum was processed for vertebrates, plant macrofossils, and insects. Vertebrate remains include teeth from deer, muskrat, and vole as well as plates from a turtle shell. At least 6000 insect fragments from a minimum of 19 Coleoptera families were identified. The most common groups are hydrophilids and dytiscids (water beetles), curculionids (weevils), staphylinids (rove beetles), and carabids (ground beetles). The majority of identified beetles are associated with fresh water as aquatic predators, scavengers, or grazers, while others prefer hygric substrates and moist plant litter. The large number of plant-dependent beetles, the numerous floating and emergent aquatic plant seeds, and the presence of the associated vertebrates point toward a locally rich and varied flora and fauna, probably deposited in a well-vegetated pond. The modern distributions and ecologies of the identified fossil insects suggest temperatures similar to those found in southern Ontario today. On these grounds the Innerkip peat represents either a very warm interstadial or a possible interglacial deposit. If the latter is true this is the second presumed Sangamon-aged site known in southern Ontario.


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