6 research outputs found
Glacial history of the Kuznetsky Alatay Mountains
No full textField investigations showed that the leeward slopes across the Kuznetsky Alatay Mountains (also the windward slopes in the Tigertysh ridge) are intensively eroded by glaciers and represent the classical type of “alpine-type landscape”. Accumulative glacial landforms are developed in all types of glacial valleys. Study of five valleys (the Karatas, the Lower and the Upper Tayzhasu, Perekhodnya, the right source of the Small Kazyr Rivers) showed that four stadial moraine complexes can be identified. These moraines are very different by their morphology. They indicate the change of glaciation from large ancient valley glaciers to modern small cirque and slope glaciers. In this article, the first data are assessed about evolution of glaciers and climate in the Kuznetsky Alatay Mountains from the Last Glacial Maximum of Late Pleistocene (between 26,500 and 19,000–20,000 years BP) to nowadays on the basis of studies of glacial landforms, sedimentology, and biostratigraphy. In the Glacier inventory complied in 1970s-early 1980s, 91 glaciers were recorded in the Kuznetsky Alatay; however, some were erroneously identified as glaciers. The review of the current changes of modern glaciation of the Kuznetsky Alatay is made on the basis of repeated photographs and direct field measurements of 30 glaciers. 18 out of the 30 studied glaciers melted away completely, their area decreased from 1.4 to 0.5–0.3 km2. Not all glaciers strongly degraded. Large cirque glaciers have not changed significantly. Over the past 110 years, the area of perennial snowfields in the Kuznetsky Alatay Mountains had reduced by 90 %. Over the century, the timberline has risen by about 50 m and is currently located at 1220–1200 m a.s.l
Glacial history of the Kuznetsky Alatay Mountains
No full textField investigations showed that the leeward slopes across the Kuznetsky Alatay Mountains (also the windward slopes in the Tigertysh ridge) are intensively eroded by glaciers and represent the classical type of “alpine-type landscape”. Accumulative glacial landforms are developed in all types of glacial valleys. Study of five valleys (the Karatas, the Lower and the Upper Tayzhasu, Perekhodnya, the right source of the Small Kazyr Rivers) showed that four stadial moraine complexes can be identified. These moraines are very different by their morphology. They indicate the change of glaciation from large ancient valley glaciers to modern small cirque and slope glaciers. In this article, the first data are assessed about evolution of glaciers and climate in the Kuznetsky Alatay Mountains from the Last Glacial Maximum of Late Pleistocene (between 26,500 and 19,000–20,000 years BP) to nowadays on the basis of studies of glacial landforms, sedimentology, and biostratigraphy. In the Glacier inventory complied in 1970s-early 1980s, 91 glaciers were recorded in the Kuznetsky Alatay; however, some were erroneously identified as glaciers. The review of the current changes of modern glaciation of the Kuznetsky Alatay is made on the basis of repeated photographs and direct field measurements of 30 glaciers. 18 out of the 30 studied glaciers melted away completely, their area decreased from 1.4 to 0.5–0.3 km2. Not all glaciers strongly degraded. Large cirque glaciers have not changed significantly. Over the past 110 years, the area of perennial snowfields in the Kuznetsky Alatay Mountains had reduced by 90 %. Over the century, the timberline has risen by about 50 m and is currently located at 1220–1200 m a.s.l
Climate change and the size of glaciers in the Kuznetsky Alatau Mountains between 1975 and 2015
Get PDFClimate change in the Kuznetsky Alatau (Western Siberia) highlands (on its eastern macroslope) was investigated using data of the Nenasthaya weather station collected for the last 40 years. It is the only highland station functioning now in the area under investigation. Basing on the correlation between average daily temperatures for the period 1974–1975, obtained at the Nenasthaya station and meteopost Karatash (located in front of the Kartash Glacier), we believe that the Nenasthaya one is enough representative for analysis of the climate in this glacio-nival zone. Linear trends for mean summer temperatures and annual precipitation sums had been calculated. Analysis of the linear trends has indicated that for the last 40 years the average summer temperature in the Kuznetsky Alatau increased by 1.3 °C with the growth rate of 0.33 °C/10 years. Average annual precipitation has also increased by 320 mm (the growth rate is 80 mm/10 years). These climatic changes did cause corresponding reactions of glaciers in the area. The analysis of current changes in the glacio-nival systems demonstrated that different morphological types of glaciers reacted to the current climate change in different ways. Small slope glaciers and perennial snowfields degraded significantly (70–90% of the area had melted) due to the temperature rise. Some ones transformed into the category of perennial snowfields. Large corrie glaciers located on the leeward slopes of wide watersheds in the negative relief forms did only slight retreat. They mostly continue to exist because the amount of accumulated snow mass increased and, thus, compensated the ablation. The largest decrease in the area of glaciers took place in 2002–2004. Since 2005, large glaciers stopped to degrade and were in relative equilibrium with climate. This article presents estimation of dynamics of the Kuznetsky Alatau glaciers since their cataloging made in the 1980-s, and it contains the detailed information about fluctuation of areas of glaciers Karatash № 56, Cherno-Iyussky № 83, and Tsentralny № 87 in 1975–2015 received from data obtained in field measurements and remote sensing methods. The area increase of some individual glaciers since 2005 is shown. An effort to compare dynamics of main climatic factors having impact on the glaciations with the dynamics of the glacier areas had been made
Late Kungurian Radioisotope Age of the Boundary Between the Balakhonka and Kolchugino Groups in the Kuznetsk Basin (Western Siberia, Russia) – Additional Evidence for the Validity of the Ufimian Stage of the East European Permian
No full textThis article discusses the Late Kungurian radioisotopic age (276.9 ± 0.4 Ma) of the middle part of the Starokuznetsk Formation (Kuznetsk Subgroup, Kolchugino Group) of the Kuznetsk Basin determined by chemical abrasion–isotope dilution–thermal ionization mass spectrometry (CA-ID-TIMS). The analysis of the biostratigraphic data confirms that the layer dated belongs to the interval in which the Balakhonka Flora (cordaitoid) was replaced by the Kolchugino Flora (fern-pteridosperm-cordaitoid). This indicates that the change from the Balakhonka Flora to the Kolchugino Flora in the low latitudes of Angaraland took place during the Late Kungurian. The data obtained were used for direct correlation of the lower part of the Kolchugino Group with the Upper Kungurian of the International Chronostratigraphic Chart. Similar sequences of non-marine bivalve assemblages in the Permian successions of Angaraland (giant Prokopievskia, Khosedaella-Redikorella-Palaeomutela, and dominant Palaeomutela) and Eastern Europe (giant Sinomya, Palaeomutela-Khosedaella-Redikorella, and dominant Palaeomutela) further support the validity of the correlation of the Kuznetsk Subgroup with the Ufimian Stage. The placement of the lower boundary of the Kolchugino Group in the upper part of the Kungurian Stage of the International Chronostratigraphic Scale raises the question of the continuation of the Ufimian Stage as an independent straton in the East European Stratigraphic Scale. Its lower boundary coincides with the beginning of the change in the Balakhonka and Kolchugino Flora in the low latitudes of Angaraland, as well as with the faunal exchanges between the Euramerican and Angarian non-marine bivalve assemblages
First radiometric dating of tonsteins from coal-bearing succession of the Kuznetsk Basin: U-Pb geochronology of the Tailugan Formation
No full textTonsteins, predominantly solid kaolinite clay interbeds, are widespread in the coals of the Kuznetsk Basin and usually contain idiomorphic zircon grains of magmatic origin in quantities suitable for uranium-lead (U-Pb) radiometric dating. For the first time, tonstein zircons from coal seam 78 of the Tailugan Formation (Fm) are dated by two methods: Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) and Chemical Abrasion Isotope-Dilution Thermal Ionization Mass Spectrometry (CA-ID-TIMS).The CA-ID-TIMS datings of 257.0 ± 1.3 Ma and 256.6 ± 0.4 Ma determine the age of the lower boundary of the Tailugan Fm and the Tailuganian Regional Stage at 257.0 Ma. We estimate the duration of the Tailuganian to be around 4.22 million years. The dating results make it possible to directly correlate the Tailuganian of the Kuzbass with the upper half of the Wuchiapingian and with most of the Changhsingian of the International Chronostratigraphic Scale.The accumulation rate of total sediments of the Tailugan Fm, calculated without considering the compaction index, is approximately 0.13–0.18 mm/year, and the rate of coal accumulation is 0.024 mm/year. Such values are comparable to the accumulation rates of the Late Paleozoic coal-bearing strata of the Donetsk Basin and Western Australia. The rate of peat accumulation during the Tailuganian, calculated at a compaction index of 10:1, has been estimated at 0.24 mm/year. This value is comparable to the rates of peat accumulation in the Holocene bogs of the Kuznetsk Alatau in Siberia and the European part of Russia.The presence of tonsteins in the coal seams of the Tailugan Fm suggests that the upper surface of the peat at the time of its accumulation was below the water level, serving as a protective screen for the thin volcanic deposits and preventing its erosion.The assemblages of macroflora, ostracods, conchostracans and bivalves considerably vary through the section of the Tailugan Fm. This variation makes it possible to identify in Kuzbass the stratigraphic level that corresponds to the boundary between the Wuchiapingian and Changhsingian stages in the future
Изменение климата и размеров ледников в горах Кузнецкого Алатау в 1975-2015 гг.
Get PDFClimate change in the Kuznetsky Alatau (Western Siberia) highlands (on its eastern macroslope) was investigated using data of the Nenasthaya weather station collected for the last 40 years. It is the only highland station functioning now in the area under investigation. Basing on the correlation between average daily temperatures for the period 1974–1975, obtained at the Nenasthaya station and meteopost Karatash (located in front of the Kartash Glacier), we believe that the Nenasthaya one is enough representative for analysis of the climate in this glacio-nival zone. Linear trends for mean summer temperatures and annual precipitation sums had been calculated. Analysis of the linear trends has indicated that for the last 40 years the average summer temperature in the Kuznetsky Alatau increased by 1.3 °C with the growth rate of 0.33 °C/10 years. Average annual precipitation has also increased by 320 mm (the growth rate is 80 mm/10 years). These climatic changes did cause corresponding reactions of glaciers in the area. The analysis of current changes in the glacio-nival systems demonstrated that different morphological types of glaciers reacted to the current climate change in different ways. Small slope glaciers and perennial snowfields degraded significantly (70–90% of the area had melted) due to the temperature rise. Some ones transformed into the category of perennial snowfields. Large corrie glaciers located on the leeward slopes of wide watersheds in the negative relief forms did only slight retreat. They mostly continue to exist because the amount of accumulated snow mass increased and, thus, compensated the ablation. The largest decrease in the area of glaciers took place in 2002–2004. Since 2005, large glaciers stopped to degrade and were in relative equilibrium with climate. This article presents estimation of dynamics of the Kuznetsky Alatau glaciers since their cataloging made in the 1980-s, and it contains the detailed information about fluctuation of areas of glaciers Karatash № 56, Cherno-Iyussky № 83, and Tsentralny № 87 in 1975–2015 received from data obtained in field measurements and remote sensing methods. The area increase of some individual glaciers since 2005 is shown. An effort to compare dynamics of main climatic factors having impact on the glaciations with the dynamics of the glacier areas had been made.Статья посвящена анализу изменений климата и нивально-гляциальных систем гор Кузнецкого Алатау (Западная Сибирь) за последние 40 лет. Установлен факт увеличения площади отдельных крупных ледников района. Колебания ледников рассматриваются на фоне трендов изменения средних летних температур воздуха и годового количества осадков по метеостанции Ненастная – единственной высокогорной станции в горах Кузнецкого Алатау
