scholarly journals Application of Rock Weathering and Colonization by Biota for the Relative Dating of Moraines from the Arid Part of the Russian Altai Mountains

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 342
Author(s):  
Dmitrii A. Ganyushkin ◽  
Sofia N. Lessovaia ◽  
Dmitrii Y. Vlasov ◽  
Gennady P. Kopitsa ◽  
László Almásy ◽  
...  

For the Altai Mountains’ region, especially the arid southeastern part of the Russian Altai, the data on glacier fluctuations in the Pleistocene and Holocene are still inconsistent. The study area was the Kargy River’s valley (2288–2387 m a.s.l.), a location that is not currently affected by glaciation and the glacial history of which is poorly studied. Field observations and geomorphological mapping were used to reveal the configuration of Pleistocene moraines. The relative dating method was applied to define the degree of weathering as an indicator of age. Three moraine groups of different ages (presumably MIS 6, MIS 4, and MIS 2) were identified based on a detailed investigation of their morphological features and the use of relative dating approaches. The latter were primarily based on weathering patterns. Data on the rock mineralogy, porosity, and specificity of biological colonization as an agent of weathering were obtained for the moraine debris. The studied moraines were composed of fine-grained schist, in which the specific surface area and fractality (self-similarity) were more developed in the older moraine. The growth of biota (crustose lichen and micromycetes) colonizing the rock surface led to rock disintegration and the accumulation of autochthonous fragments on the rock surface. Despite the fact that the initial stage(s) of moraine weathering affected by biota was fixed, the correlation trends of biota activity and moraine ages were not determined.

Author(s):  
Dmitrii A. Ganyushkin ◽  
Sofya N. Lesovaya ◽  
Dmitrii Y. Vlasov ◽  
Gennady P. Kopitsa ◽  
László Almásy ◽  
...  

For the Altai mountainous region, especially the arid south-eastern part, the history of glacier fluctuations in Pleistocene and Holocene is still poorly known. The key plots were located in the Kargy valley (2288-2387 m a. s. l.) that is not currently affected by glaciations. The relative dating method was applied to define Pleistocene moraine chronology and configuration in the Kargy valley. Taking into account that relative dating methods are primarily based on weathering pat-terns, the mineralogy, porosity, and specificity of biological colonization as an agent of weath-ering were obtained for the moraine samples. Three moraine groups of different age (presumably MIS 6, MIS 4, and MIS 2) were identifies based on detailed investigation of morphological features. The moraine age was indirectly confirmed by the mesostructure of the moraine samples repre-sented by fine-grained shale: the older sample is characterized by a more developed fractal sur-face than the younger one. The growth of biota (crustose lichen and micromycetes) leads to initial biomass accumulation and subsequent rock disintegration. The accumulation of autochthonous fine earth on the rock surface was considered the initial stage of fine earth formation affected by biota.


2015 ◽  
Vol 65 (3) ◽  
pp. 389-401 ◽  
Author(s):  
Maciej Dąbski

AbstractThis article presents the results of weathering micro-roughness measurements performed with the use of a Handy-surf E-35B electronic profilometer, a new tool in geomorphological studies. Measurements were performed on glacially abraded basaltic surfaces within the Little Ice Age (LIA) glacial forelands of Hoffelsjökull, Fláajökull, Skálafellsjökull and Virkisjökull in Iceland. Results show a statistical increase in micro-roughness in a direction from the glacial termini to LIA moraines. However, a major change in the micro-roughness of basaltic surfaces only occurs during the first 80 to 100 years since the onset of subaerial weathering. Increase in rock surface micro-roughness is accompanied by an increase in weathering rind thickness and a decrease in Schmidt hammer R-values. Micro-roughness measurements with the use of the Handysurf E-35B can provide insights into initial rates of rock surface micro-relief development. The use of this instrument as a relative dating technique is limited to fine-grained rocks and decadal time-scales of weathering because of the limited range of measureable micro-relief amplitude.


2021 ◽  
Vol 13 (7) ◽  
pp. 1316
Author(s):  
Jia Liu ◽  
Zongyu Yue ◽  
Kaichang Di ◽  
Sheng Gou ◽  
Shengli Niu

The age of Mars yardangs is significant in studying their development and the evolution of paleoclimate conditions. For planetary surface or landforms, a common method for dating is based on the frequency and size distribution of all the superposed craters after they are formed. However, there is usually a long duration for the yardangs’ formation, and they will alter the superposed craters, making it impossible to give a reliable dating result with the method. An indirect method by analyzing the ages of the superposed layered ejecta was devised in the research. First, the layered ejecta that are superposed on and not altered by the yardangs are identified and mapped. Then, the ages of the layered ejecta are derived according to the crater frequency and size distribution on them. These ages indicate that the yardangs ceased development by these times, and the ages are valuable for studying the evolution of the yardangs. This indirect dating method was applied to the areas of Martian yardangs in the Medusae Fossae Formation (MFF). The ages of the selected six layered ejecta range from ~0.50 Ga to ~1.5 Ga, indicating that the evolution of the corresponding yardangs had been ceased before these times. Analysis of more layered ejecta craters and superposed yardangs implies that yardangs in the MFF have a long history of development and some yardangs are still in active development.


Author(s):  
Natalia A. Chernova ◽  
Marina N. Belova ◽  
Elena E. Timoshok ◽  
Eugeny N. Timoshok ◽  
Sergey N. Skorokhodov

Author(s):  
MUKAEVA L. ◽  

The article considers the history of the creation and development of the first Russian village in the Altai Mountains - the village of Cherga, which appeared in 1820-s a settlement of peasants assigned to the Cabinet mining plants. According to the author, Cherga played an important role in the economic development of the north-western part of the Altai Mountains. Cherga peasants were successfully engaged in arable farming, cattle breeding, mountain beekeeping, private hauling and taiga fisheries. In the vicinity of Cherga in the second half of the 19th century, there were large dairy farms of entrepreneurs who used advanced technologies and innovations in their farms. In Soviet times, Cherga with the surrounding villages turned into a large multi-industry state farm in the Altai Mountains. The traditions of innovation in Cherga were fully manifested in the 1980-s, when the Altai Experimental Farm of the Siberian Branch of the Academy of Sciences of USSR was formed on the basis of the Cherginsky State Farm, which was still active at the beginning of the 20th century. Keywords: Seminskaya Valley, Cherga, peasants, economic development, Altai experimental farm SB RAS


Author(s):  
Oksana Babenko ◽  

The review presents new publications on the Belarusian and the Polish historiographies of the history of the late Imperial Russia and the Soviet State. Such problems as the number and conditions of detention of foreign prisoners of war in the Belarusian territories of the Russian Empire during the First World War, the influence of the military conflicts of 1914-1921 on the identity of the inhabitants of the Belarusian lands, the initial stage of the formation of academic science in the BSSR, the question of the «invasion» of Poland by the Red Army in September 1939 are highlighted.


1998 ◽  
Vol 62 (2) ◽  
pp. 197-212 ◽  
Author(s):  
Anju Tiwary ◽  
Mihir Deb ◽  
Nigel J. Cook

AbstractPyrite is an ubiquitous constituent of the Proterozoic massive sulphide deposit at Deri, in the South Delhi Fold Belt of southern Rajasthan. Preserved pyrite microfabrics in the Zn-Pb-Cu sulphide ores of Deri reveal a polyphase growth history of the iron sulphide and enable the tectono-thermal evolution of the deposit to be reconstructed.Primary sedimentary features in Deri pyrites are preserved as compositional banding. Regional metamorphism from mid-greenschist to low amphibolite facies is recorded by various microtextures of pyrite. Trails of fine grained pyrite inclusions within hornblende porphyroblasts define S1-schistosity. Pyrite boudins aligned parallel to S1 mark the brittle–ductile transformation of pyrite during the earliest deformation in the region. Isoclinal to tight folds (F1 and F2) in pyrite layers relate to a ductile deformation stage during progressive regional metamorphism. Peak metamorphic conditions around 550°C, an estimation supported by garnet–biotite thermometry, resulted in annealing of pyrite grains, while porphyroblastic growth of pyrite (up to 900 µm) took place along the retrogressive path. Brittle deformation of pyrite and growth of irregular pyritic mass around such fractured porphyroblasts characterize the waning phase of regional metamorphism. A subsequent phase of stress-free, thermal metamorphism is recorded in the decussate and rosette textures of arsenopyrite prisms replacing irregular pyritic mass. Annealing of such patchy pyrite provides information regarding the temperature conditions during this episode of thermal metamorphism which is consistent with the hornblendehornfels facies metamorphism interpreted from magnetite–ilmenite geothermometry (550°C) and sphalerite geobarometry (3.5 kbar). A mild cataclastic deformation during the penultimate phase produced microfaults in twinned arsenopyrite prisms.


Author(s):  
Altana M. Lidzhieva ◽  

Introduction. The article deals with the early history of Elista as a city, and makes a first attempt to anthropologically compare urban space at the initial stage of the city’s history to its current conditions. Goals. The paper examines the first and key stage in the formation and development of Elista as center of Kalmyk Autonomous Oblast. Materials. The bulk of analyzed sources are documents contained in the National Archive of the Republic of Kalmykia. Results. The work concludes that the preservation of old buildings to date is a representation of the city’s local memory. As is shown, the preservation of historical architecture proved crucial to such a representation.


Author(s):  
Evgeniy A. Gunaev ◽  

Introduction. The late 1950s restoration of autonomies for the repressed peoples is an important era in the history of those ethnic statehoods. Still, even over 60 years thereafter quite a number of issues remain essentially problematic. And the main question is as follows: Can one interpret the late 1950s restoration of autonomies for the repressed peoples of Southern Russia as a rehabilitation? Materials and Methods. The study analyzes a number of scholarly Russian historiographical publications examining the mentioned period, and employs the historical genetic and historical legal methods. Results. The article considers a range of problematic issues, such as substantial features of ‘rehabilitation’ for repressed peoples in the Soviet era, political and historical essentials of the process, general issues of periodization of the rehabilitation (including that of the Soviet era), debating aspects of the phenomenon in respect to the restoration of autonomies, contemporary political and legal aspects related to the Soviet restoration of South Russia’s ethnic autonomies. Conclusions. In Russian historiography, there is a consensus as to the identification of the period of the restoration of autonomies for the repressed peoples as a rehabilitation, though incomplete one. The paper shows observation of the principle of historicism presupposes this period be viewed in a general context of the whole Soviet era that witnessed the rehabilitation of repressed peoples pinnacled with the rehabilitation decrees of perestroika. Since 1992 there emerged a new — Russian — stage of the rehabilitation. As for critical notes on outdated norms of the RSFSR Law On the Rehabilitation of Repressed Peoples, it seems evident that the agenda of its complete implementation was never actualized by federal government agencies since the mid-1990s. It is possible that another law be created in future to comprise the rehabilitation experiences of the Soviets, including that of the initial stage from the late 1950s. This would require explicit political and legal assessments of the repressed peoples’ rehabilitation in a historical perspective.


Religions ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 933
Author(s):  
James Duncan Gentry

This article discusses Buddhist apologetics in Tibet by examining the formation, revision, and reception of the most renowned literary apologia ever written in defense of the Old School of Tibetan Buddhism: Sokdokpa Lodrö Gyeltsen’s early 17th-century magnum opus the Thunder of Definitive Meaning. It reconstructs in broad strokes the history of the Thunder’s reception from the early 17th century to the present and relates this to details in different versions of the Thunder and its addendum to shed light on the process by which this work was composed and edited. By considering this work’s peculiar context of production and history of reception alongside passages it presents revealing how it was conceived and revised, this analysis aims to prepare the ground for its study and translation. In so doing, this discussion attempts to show how a broadly historical approach can work in tandem with a fine-grained philological approach to yield fresh insights into the production and reception of Buddhist literary works that have important ramifications for their understanding and translation.


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