scholarly journals Relative Dating of Moraines from the Arid Part of Altai: Applying of Rock Weathering and Colonization by Biota Data within the Framework of the Method

2021 ◽  
Author(s):  
Dmitrii A. Ganyushkin ◽  
Sofya N. Lesovaya ◽  
Dmitrii Y. Vlasov ◽  
Gennady P. Kopitsa ◽  
László Almásy ◽  
...  
Keyword(s):  
Biomass Accumulation ◽  
Rock Surface ◽  
Fine Earth ◽  
Fine Grained ◽  
Relative Dating ◽  
Initial Stage ◽  
Dating Methods ◽  
Rock Disintegration ◽  
History Of ◽  
Dating Method

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.

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 ◽  
...  
Keyword(s):  
Rock Surface ◽  
Altai Mountains ◽  
Southeastern Part ◽  
Fine Grained ◽  
Geomorphological Mapping ◽  
Relative Dating ◽  
Initial Stage ◽  
History Of ◽  
Dating Method ◽  
Russian Altai

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.

Application of the Handysurf E-35B electronic profilometer for the study of weathering micro-relief in glacier forelands in SE Iceland

2015 ◽  
Vol 65 (3) ◽  
pp. 389-401 ◽  
Author(s):  
Maciej Dąbski
Keyword(s):  
Time Scales ◽  
Little Ice Age ◽  
Major Change ◽  
Limited Range ◽  
Ice Age ◽  
Rock Surface ◽  
Schmidt Hammer ◽  
Fine Grained ◽  
Relative Dating ◽  
Roughness Measurements

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.

scholarly journals Multiple Dating of a Long Flowstone Profile

Radiocarbon ◽  
1986 ◽  
Vol 28 (2A) ◽  
pp. 503-509 ◽  
Author(s):  
Mebus A Geyh ◽  
G J Hennig
Keyword(s):  
Growth Rate ◽  
West Germany ◽  
Spin Resonance ◽  
Dating Methods ◽  
Growth History ◽  
Order Of Magnitude ◽  
History Of ◽  
Dating Method ◽  
Closed Systems ◽  
Glacial Periods

Dense speleothem samples are considered as closed systems and are, therefore, possibilities for any dating method. Four dating methods (14C, U/Th, paleomagnetism, and electron spin resonance = ESR) were used for samples up to 1,000,000 yr old and taken along a vertical flowstone profile in the Heggen cave in West Germany. Also δ18O and δ13C analyses were carried out.The reliability of the results of each method is dependent on the diagenetic processes that took place during the complex growth history of the flowstone. Speleothem growth was interrupted during glacial periods. During interglacial periods, at least the stalagmite growth rate was greater by one order of magnitude than during interstadial periods. During the periods of low interstadial growth rate various processes might have changed the 14C, 18O, and 13C concentrations, leaching might have removed uranium, recrystallization might have moved thorium several centimeters, and increased content of radon in the cave might have exaggerated the accumulated dose (AD) at the speleothem surface. As a result, 14C ages may be too small and U/Th as well as ESR data may be too large.

Paleogene to Quaternary geodynamical evolution of the lowland Central Amazonia inferred by weathering phases dating

2020 ◽  
Author(s):  
Cecile Gautheron ◽  
Cristiana Cabriolu ◽  
Fabiano Pupim ◽  
Mauricio Parra ◽  
Stéphane Schwartz ◽  
...  
Keyword(s):  
Amazon River ◽  
Fluvial Terraces ◽  
Left Margin ◽  
Stratigraphic Framework ◽  
Dating Methods ◽  
Central Amazonia ◽  
History Of ◽  
Dating Method ◽  
Past Conditions ◽  
Lowland Amazonia

<p>The landscape in lowland Amazonia is shaped by large rivers, whose depositional-erosive dynamics built fluvial terraces covered by upland forests. Thus, fluvial deposits distributed across lowland Amazonia are of crucial relevance since they represent the best accessible archives to study the history of environment and climate change. The timing of the assembly of the modern transcontinental Amazon River is considered a key event in the landscape evolution of Amazonia, however, proposed ages range from Miocene, early Pliocene to Pliocene/Pleistocene. Therefore, regional stratigraphic correlations need to improve to ensure a better understanding of reconstructions of past conditions in Amazonia during the Cenozoic. Yet, these are difficult due to the lack of absolute ages to constrain phases of sediment deposition or erosion and weathering. In lowland central Amazonia, past environmental conditions are recorded in the Alter do Chão and Novo Remanso Formations. Both units are dominated by sandy and highly oxidized sediments with scarce paleontological remains complicating the application of biostratigraphy dating methods. The Alter do Chão and Novo Remanso Formations are well exposed in the left margin of the Solimões-Amazon River main stem and show remarkable zones rich in supergene iron weathering products, which has been used to define the stratigraphic boundaries among the Alter do Chão Formation, Novo Remanso Formation and overlying sediments. In this study, we use the (U-Th-Sm)/He dating method on goethite and hematite grains to determine the age of iron-enrichment layers and duricrusts that mark boundary surfaces used to define the stratigraphic framework of the Alter do Chão and Novo Remanso formations. The (U-Th-Sm)/He ages allow to improve chronological constraints for both formations and to discuss the timing of fluvial terraces building and weathering conditions in central Amazonia through time.</p>

scholarly journals The ‘oldest dated document of the Cairo Genizah’ (Halper 331): The Seleucid era and sectarian Jewish calendars

2021 ◽  
pp. 1-18
Author(s):  
EVE KRAKOWSKI ◽  
SACHA STERN
Keyword(s):  
Near East ◽  
Early Medieval ◽  
Near Eastern ◽  
Dating Methods ◽  
Marriage Contract ◽  
History Of ◽  
Legal Document ◽  
Cairo Genizah ◽  
Medieval Egypt

Abstract Halper 331 is the fragment of a codex that has been styled the ‘oldest dated document of the Cairo Genizah’. It preserves the opening of a Jewish legal document dated to the year 1182 (Seleucid era), which appears to have been copied into this codex, probably as a formulary, not long after this date, in the late 9th century. In this article, the text of this fragment, in Aramaic and Hebrew, is edited, and its identification as the beginning of a marriage contract (ketubbah) is evaluated. Its Egyptian provenance is questioned, partly because the earliest evidence for the introduction of the Seleucid era by Jews in Egypt dates from the mid-10th century. The article surveys the history of Jewish dating methods in early medieval Egypt and the Near East, in an attempt to clarify this question. The specific date of the document deviates from the rabbinic calendar, but agrees with that of the contemporary Jewish Near Eastern sectarian groups of Abū ʿImrān al-Tiflīsī and Ismāʿīl al-ʿUkbarī; this document could thus uniquely attest one of these sectarian Jewish calendars.

scholarly journals A Study about the Temporal Constraints on the Martian Yardangs’ Development in Medusae Fossae Formation

2021 ◽  
Vol 13 (7) ◽  
pp. 1316
Author(s):  
Jia Liu ◽  
Zongyu Yue ◽  
Kaichang Di ◽  
Sheng Gou ◽  
Shengli Niu
Keyword(s):  
Size Distribution ◽  
Indirect Method ◽  
Common Method ◽  
Planetary Surface ◽  
Temporal Constraints ◽  
History Of Development ◽  
Long Duration ◽  
History Of ◽  
Dating Method

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.

NEW SCIENTIFIC WORKS ON THE MODERN BELARUSIAN AND POLISH HISTORIOGRAPHY OF THE HISTORY OF THE LATE IMPERIAL RUSSIA AND THE SOVIET STATE

2021 ◽  
pp. 76-88
Author(s):  
Oksana Babenko ◽  
Keyword(s):  
Prisoners Of War ◽  
Academic Science ◽  
Soviet State ◽  
Late Imperial ◽  
Imperial Russia ◽  
Initial Stage ◽  
Red Army ◽  
History Of ◽  
The Russian Empire ◽  
The Military

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.

Use of pyrite microfabric as a key to tectono-thermal evolution of massive sulphide deposits – an example from Deri, southern Rajasthan, India

1998 ◽  
Vol 62 (2) ◽  
pp. 197-212 ◽  
Author(s):  
Anju Tiwary ◽  
Mihir Deb ◽  
Nigel J. Cook
Keyword(s):  
Thermal Evolution ◽  
Regional Metamorphism ◽  
Massive Sulphide ◽  
Ductile Deformation ◽  
Sulphide Deposit ◽  
Fine Grained ◽  
Thermal Metamorphism ◽  
Sulphide Ores ◽  
History Of ◽  
South Delhi Fold Belt

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.

scholarly journals «Люди ехали и верили: город будет!». К истории становления Элисты как города в 1928–1930 годах

2020 ◽  
Vol 12 (4) ◽  
pp. 764-777
Author(s):  
Altana M. Lidzhieva ◽  
Keyword(s):  
Urban Space ◽  
National Archive ◽  
Early History ◽  
Local Memory ◽  
Initial Stage ◽  
History Of ◽  
Historical Architecture ◽  
The Republic

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.

scholarly journals Восстановление автономий репрессированных народов Калмыкии и Северного Кавказа в конце 1950-х гг. и проблема реабилитации: дискуссионные вопросы в современной российской историографии

2021 ◽  
Vol 14 (1) ◽  
pp. 74-86
Author(s):  
Evgeniy A. Gunaev ◽  
Keyword(s):  
Federal Government ◽  
Historical Perspective ◽  
Legal Aspects ◽  
General Context ◽  
Government Agencies ◽  
Main Question ◽  
Initial Stage ◽  
History Of ◽  
Southern Russia ◽  
Critical Notes

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.

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