scholarly journals Linking Siberian Traps LIP Emplacement and End-Permian Mass Extinction: Evidence from Magnetic Stratigraphy of the Maymecha-Kotuy Volcanic Section

Geosciences ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 295
Author(s):  
Anton V. Latyshev ◽  
Anna M. Fetisova ◽  
Roman V. Veselovskiy
Keyword(s):  
Siberian Platform ◽  
Total Duration ◽  
Magmatic Activity ◽  
Biotic Crisis ◽  
Siberian Traps ◽  
Lava Sequence ◽  
Composite Section ◽  
Permian Mass Extinction ◽  
In The Beginning ◽  
Almost All

The Siberian Traps Large Igneous Provinces (LIP) emplacement is considered as one of possible triggers for the end-Permian global biotic crisis. However, relative timing of the onset of extinction and the main phase of the magmatic activity are not yet accurately constrained. We present the detailed paleomagnetic data for the thickest composite section of the Siberian Traps volcanics, located in the Maymecha-Kotuy region. The major part of the Maymecha-Kotuy section erupted in the beginning of Early Triassic period and postdate came the onset of the biotic crisis. However, the initial pulse of volcanic activity in this region took place at the end of the Permian period, and likely preceded the extinction event, being nearly coeval to the lowest part of tuff-lava sequence of Norilsk. The suggested correlation scheme of volcanic sections from different regions of the Siberian platform shows that explosive and extrusive events foregoing the onset of extinction can be identified in almost all regions of the Siberian Traps LIP. Finally, we estimate the total duration of magmatic activity in the Maymecha-Kotuy region as ~2 Myr and assume that this lasted after the termination of eruptions in other parts of the Siberian platform.

Correlation of the Permian-Triassic Ore-Bearing Intrusions of the Norilsk Region with the Volcanic Sequence of the Siberian Traps Based on the Paleomagnetic Data

2020 ◽  
Vol 115 (6) ◽  
pp. 1173-1193 ◽  
Author(s):  
A. V. Latyshev ◽  
V. A. Rad’ko ◽  
R. V. Veselovskiy ◽  
A. M. Fetisova ◽  
V. E. Pavlov
Keyword(s):  
Siberian Platform ◽  
Platinum Group Element ◽  
Group Element ◽  
Genetic Models ◽  
The Other ◽  
Paleomagnetic Data ◽  
Magmatic Activity ◽  
Siberian Traps ◽  
Secular Variations ◽  
Element Bearing

Abstract We present detailed paleomagnetic data from the Permian-Triassic Cu-Ni-Pt–bearing intrusions of the Norilsk region (northwestern Siberian platform). Based on the analysis of geomagnetic secular variations recorded in the intrusions, we correlate the Norilsk ore-bearing intrusions with the Siberian Traps volcanic sequences in the region. The similarity of paleomagnetic directions of the ore-bearing intrusions to those of the Morongovsky and Mokulaevsky volcanic formations suggests that the emplacement of these lavas and intrusions occurred during the same stage of the magmatic activity. Furthermore, some weakly mineralized intrusions and barren nondifferentiated sills demonstrate paleomagnetic directions close to those of the ore-bearing intrusions. This implies that ore-bearing, weakly mineralized, and barren intrusions were emplaced during the same stage of magmatic activity. On the other hand, the paleomagnetic directions of different ore-bearing intrusions (Norilsk 1, Talnakh, and Kharaelakh), while close, are statistically different. Thus, the formation of these three intrusions and their satellites corresponds to discrete magmatic events within the same stage of magmatic activity. Based on the paleomagnetic data, the emplacement duration of individual intrusions can be estimated as <10 k.y. Our correlation scheme is consistent with some genetic models for the ore-bearing intrusions. The analysis of geomagnetic secular variations can be used as an independent tool for the investigation of other Cu-Ni and platinum group element-bearing magmatic complexes.

New apatite fission track thermochronology data from the Siberian Permian-Triassic Traps

2020 ◽  
Author(s):  
Tanya Bagdasaryan ◽  
Roman Veselovskiy ◽  
Maria Myshenkova ◽  
Viktor Zaitsev ◽  
Stuart Thomson ◽  
...  
Keyword(s):  
Siberian Platform ◽  
Thermal History ◽  
Fission Track ◽  
Thermal Evolution ◽  
Total Duration ◽  
Large Igneous Province ◽  
Apatite Fission Track ◽  
Siberian Traps ◽  
Fission Track Thermochronology ◽  
First Results

<p>The thermal history of the Siberian platform has not been studied and only single thermochronological study is available now [Rosen et al., 2009]. According to high-precision U-Pb dating the main phase of magmatic activity of the Siberian Traps Large Igneous Province took place ~252.0-251.3 Ma [Kamo et al., 2003] and its duration didn’t exceed ~1 Myr. But according to Ar/Ar dating (~240 Ma) [Ivanov et al., 2013] the total duration of the Siberian Traps formation may be estimated as long as ~10 Myr. In addition, single apatite fission track (AFT) ages are approximately 222-185 Ma [Rosen et al., 2009].</p><p>We present the first results of AFT dating from the Guli pluton and computer modeling of its post-magmatic cooling, as well as some new AFT ages from other magmatic bodies within the Siberian platform. Based on these data we present the first model of the tectonothermal evolution of the Siberian platform in Mesozoic and Cenozoic.</p><p>The Guli massif is located within the Maymecha-Kotuy region of the Siberian Permian-Triassic Traps and is the world's largest alkaline-ultrabasic complex. Results of U-Pb dating of baddeleyite from the carbonatites – the latest intrusion phase – 250.2±0.3 Ma [Kamo et al., 2003] correspond to the time of massif’s crystallization.</p><p>AFT dating was conducted by an external detector method at the University of Arizona (Tucson). The fission track ages of the Guli are in the range of ~250-231 Ma with the mean standard error (1σ) ±34 Myr. In addition, we obtain five new AFT ages as well as U-Pb age obtained from different intrusive bodies within the Siberian platform: Kontayskaya intrusion, Odikhincha massif and Padunsky sill. All obtained AFT ages are in the range of 195-173 ±13 (1σ) Ma, which corresponds to the Early-Middle Jurassic. At the same time, the U-Pb LA-ICPMS age of apatite from Padunsky sill is 242±7 Ma.</p><p>Thermal history modeling using fission track age data and track lengths distribution was performed in HeFTy v.1.8.3. Based on the obtained results we consider the following model of tectonic-thermal evolution of the studied intrusive massifs: (1) the emplacement of intrusions ca. 250 Ma; (2) their burial under a thick sedimentary (volcanic?) cover; (3) regional exhumation and cooling below 110°C about 220-190 Ma.</p><p>The research was carried out with the support of RFBR (grants 18-35-20058 and 18-05-00590) and Programs of development of Lomonosov Moscow State University.</p>

COMMERCIAL FAUNA OF WA-TERBODIES IN THE MOSCOW RIVER BASIN IN THE SECOND HALF OF THE 18th CENTURY

2021 ◽  
pp. 94-112
Author(s):  
N. Ozerova
Keyword(s):  
River Basin ◽  
Fish Species ◽  
18Th Century ◽  
Commercial Fish ◽  
Acipenser Ruthenus ◽  
Land Survey ◽  
Ancient Times ◽  
In The Beginning ◽  
Almost All ◽  
Moscow River

Based on the data from economic notes to the General Land Survey, the ranges of commercial fish and crayfish species that inhabited waterbodies of the Moscow River basin in the second half of the 18th century are reconstructed. Eighteen maps showing the distribution of 22 fish species, including Acipenser ruthenus L., Abramis brama L., Barbatula barbatula L., Lota lota L., Sander lucioperca L. and others are compiled. Comparison of commercial fish species that lived in the Moscow River basin in the second half of the 18th century with data from ichthyological studies in the beginning of the XXI century and materials of archaeological surveys shows that almost all of these species have lived in the Moscow River basin since ancient times and have survived to the present day.

STUDY ON THE FORMATION MECHANISM OF TANGJIASHAN LANDSLIDE TRIGGERED BY WENCHUAN EARTHQUAKE USING DDA SIMULATION

2011 ◽  
Vol 08 (02) ◽  
pp. 229-245 ◽  
Author(s):  
AIQING WU ◽  
QIGUI YANG ◽  
GUISHENG MA ◽  
BO LU ◽  
XIAOJUN LI
Keyword(s):  
Wenchuan Earthquake ◽  
High Speed ◽  
Total Duration ◽  
Sliding Surface ◽  
Geological Investigation ◽  
Earthquake Load ◽  
Nonlinear Features ◽  
Displacement Based ◽  
Static Conditions ◽  
In The Beginning

Wenchuan earthquake, Ms 8.0 in magnitude and occurred on May 12, 2008 in Sichuan Province, China, triggered a lot of landslides, rock collapses, debris flow, etc. The Tangjiashan landslide, with its total volume 20.37 million m3, was the biggest and the most notable one for its effects. Based on the field geological investigation and the typical acceleration records of the main shock obtained in the period of the earthquake, numerical simulation of the whole sliding process of Tangjiashan landslide has been carried out by DDA method. It is shown that the Tangjiashan landslide was a high-speed landslide, behaved with nonlinear features in the whole sliding process. The total duration of the landslide was about 30 s while nearly all of their slipping displacements were carried out in the beginning 25 s, with the maximum sliding velocity about 30 m/s, and the average 15–17 m/s in the beginning 25 s. The crash of rock blocks induced a much higher stresses near the middle and lower parts of the landslide, with the maximum value of 6–7 MPa. The dynamic earthquake load caused an incessant deformation of the landslide, resulting in the reduction of mechanical parameters, especially the shear strength on the sliding surface and the ratio of friction coefficient on sliding surface in kinematical and static conditions are no more than 0.35. DDA simulation considering the displacement-based parameter reduction has been developed in the original DDA code, and its results primarily reflect the evolvement process of a landslide under strong seismic loads.

Historical Account or Discourse on Identity? A Reexamination of Fulbe Hegemony and Autochthonous Submission in Banyo

1998 ◽  
Vol 25 ◽  
pp. 93-110 ◽  
Author(s):  
Quentin Gausset
Keyword(s):  
Nineteenth Century ◽  
The Other ◽  
Islamic State ◽  
Local Populations ◽  
Northern Cameroon ◽  
Definition Of ◽  
Historical Accounts ◽  
In The Beginning ◽  
Almost All ◽  
The Military

Traditional accounts of the nineteenth-century Fulbe conquest in northern Cameroon tell roughly the same story: following the example of Usman Dan Fodio in Nigeria, the Fulbe of Cameroon organized in the beginning of the nineteenth century a “jihad” or a “holy war” against the local pagan populations to convert them to Islam and create an Islamic state. The divisions among the local populations and the military superiority of the Fulbe allowed them to conquer almost all northern Cameroon. They forced those who submitted to give an annual tribute of goods and servants, and they raided the other groups. In these traditional accounts the Fulbe are presented as unchallenged masters, while the local populations are depicted as slaves who were powerless over their fate; their role in the conquest of the region and in the administration of the new political order is supposed to have been insignificant.I will show that, on the contrary, in the area of Banyo the Wawa and Bute played a crucial role in the conquest of the sultanate and in its administration. I will then re-examine the cliche that all members of the local populations were the slaves of the Fulbe by distinguishing the fate of the Wawa and Bute on one side from that of the Kwanja and Mambila on the other, and by showing the importance of the Fulbe's identity in shaping the definition of slavery. Finally I will argue that, if the historical accounts found in the scientific literature invariably insist on Fulbe hegemony and minimize the role played by the local populations, it is because those accounts are often based on Fulbe traditions, and because these traditions are remodeled by the Fulbe in order to correspond to their discourse on identity.

scholarly journals The main pulse of the Siberian Traps expanded in size and composition

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
L. E. Augland ◽  
V. V. Ryabov ◽  
V. A. Vernikovsky ◽  
S. Planke ◽  
A. G. Polozov ◽  
...  
Keyword(s):  
Volcanic Activity ◽  
Volcanic Rocks ◽  
West Siberia ◽  
Main Pulse ◽  
Environmental Consequences ◽  
Siberian Traps ◽  
Minimum Age ◽  
Area North ◽  
Permian Mass Extinction ◽  
Compositional Diversity

AbstractEmplacement of large volumes of (sub)volcanic rocks during the main pulse of the Siberian Traps occurred within <1 m.y., coinciding with the end-Permian mass extinction. Volcanics from outside the main Siberian Traps, e.g. Taimyr and West Siberia, have since long been correlated, but existing geochronological data cannot resolve at a precision better than ~5 m.y. whether (sub)volcanic activity in these areas actually occurred during the main pulse or later. We report the first high precision U-Pb zircon geochronology from two alkaline ultramafic-felsic layered intrusive complexes from Taimyr, showing synchronicity between these and the main Siberian Traps (sub)volcanic pulse, and the presence of a second Dinerian-Smithian pulse. This is the first documentation of felsic intrusive magmatism occurring during the main pulse, testifying to the Siberian Trap’s compositional diversity. Furthermore, the intrusions cut basal basalts of the Taimyr lava stratigraphy hence providing a minimum age of these basalts of 251.64 ± 0.11 Ma. Synchronicity of (sub)volcanic activity between Taimyr and the Siberian Traps imply that the total area of the Siberian Traps main pulse should include a ~300 000 km2 area north of Norilsk. The vast aerial extent of the (sub)volcanic activity during the Siberian Traps main pulse may explain the severe environmental consequences.

Tweetalig Kleuter- en Lager Onderwijs in Friesland, Een Beschouwing van de Stand van Zaken

1983 ◽  
Vol 15 ◽  
pp. 93-109
Author(s):  
Theun Meestringa
Keyword(s):  
Primary Schools ◽  
The Other ◽  
Substantial Part ◽  
Medium Of Instruction ◽  
Regional Dialects ◽  
Main Motive ◽  
State Of Affairs ◽  
In The Beginning ◽  
Almost All ◽  
Regional Languages

Since August 1980 both Frisian and Dutch have been compulsory subjects in the primary schools in the province of Friesland. This article describes the present situation. It begins with a descrip-tion of the motives for bilingual education in Friesland and relates them to the typology of Fishman. This appears to clarify the position of regional languages and dialects in infant and primary education. In the beginning of the eighties the position of the Frisian language in both schooltypes was investigated. About 45% of the teachers of infant groups use Dutch as a medium of instruction in almost all activities, and about 10% does nearly everything in Frisian. The other 45% use both languages; we don't know in which way or proportion. It appears that in musical activities more than one language is used. The other regional dialects of the children are hardly ever used at all. This last statement is at this moment also true for primary schools. Frisian is a subject in almost every school (86%) and a substantial part of the schools (29%) uses it as a medium of instruction. But looking at the desirability of goals as indicated by the schools, it becomes clear that most schools still don't expect their pupils to be able to write Frisian, though most of them say that their main motive for teaching Frisian is to prepare their pupils for functioning in the bilingual culture of Friesland. Too often it seems that the schools fail in respect to at least the Frisian aspects of culture in Friesland. In other words, it may be said that partial and complete bilingu-alism are not yet found in all the infant and primary schools of Friesland. Hopefully this portrait of the state of affairs will turn out to be an instant photo: things are still developing.

Anisotropy of magnetic susceptibility in alkaline-ultramafic dikes of the Kotuy river valley: Reconstruction of magma transport during the Siberian Traps emplacement

2020 ◽  
Author(s):  
Anton Latyshev ◽  
Victor Chmerev ◽  
Victor Zaitsev
Keyword(s):  
River Valley ◽  
Magnetic Fabric ◽  
Ultramafic Rocks ◽  
Limited Area ◽  
Magmatic Activity ◽  
Contact Zones ◽  
Magma Flow ◽  
Siberian Traps ◽  
Magmatic Stage ◽  
Alkaline Lamprophyres

&lt;p&gt;Products of the Permian-Triassic magmatic activity in the Kotuy river valley consist of two contrasting in composition groups: 1) tholeiitic basalts, similar to the main volume of the Siberian Traps; 2) alkaline-ultramafic rocks which are extremely rare in other regions of the Siberian platform. Alkaline lavas and tuffs in the Kotuy river valley are exposed only in limited area (Arydzhangsky and Khardakhsky formations), however, multiphase circular plutons (Kugda, Odikhincha) and swarms of radial and parallel dikes marks the essentially wider territory of the manifestation of alkaline magmatic activity.&lt;/p&gt;&lt;p&gt;Here we present the preliminary results of the investigation of AMS in the dike complex of alkaline lamprophyres from the Kotuy river valley. The majority of dikes demonstrate I-type of the magnetic fabric, when the medium axes K2 of AMS ellipsoid is orthogonal to the contact of intrusion. In dikes where the minimal axis K3 is subvertical and maximal axis K1 is flat, we interpret this magnetic fabric as a result of cooling of the static magma column after the emplacement in the setting of horizontal extension (Park et al., 1988; Raposo and Ernesto, 1995). Also, N-type and R-type of magnetic fabric were identified as well. In some intrusions, the orientation of the axes of AMS ellipsoid changes from the contact zones to the inner part if intrusion. In this case, we used data from the contact zones for the magma flow reconstruction.&lt;/p&gt;&lt;p&gt;Analysis of the maximal axis K1 orientation in different dikes showed that in majority of bodies it shallowly plunges to the west. This corresponds to the lateral magma flow from west to east during the emplacement. Consequently, formation of the studied dikes is not directly related to Kugda pluton, which is located 8 km eastward. The emplacement of dikes occurred from the magmatic center located westward from the Kotuy river valley and is not associated with any known large massifs. Petrographic similarity of the studied dikes to the lavas of Arydzhangsky formation allows us to suggest that they are coeval. This implies the wider area of manifestation of the Arydzhangsky magmatic stage.&lt;/p&gt;&lt;p&gt;This work was supported by RFBR (projects 18-35-20058, 18-05-70094, 17-05-01121 and 20-05-00573).&lt;/p&gt;

Evolution of Larval Developmental Patterns and the Process of Freshwaterization in the Prawn Genus Macrobrachium Bate, 1868 (Decapoda, Palaemonidae)

Crustaceana ◽  
1993 ◽  
Vol 65 (3) ◽  
pp. 365-376 ◽  
Author(s):  
K.N. Sankolli ◽  
D.R. Jalihal ◽  
Shakuntala Shenoy
Keyword(s):  
Normal Type ◽  
Developmental Patterns ◽  
Suitable Candidate ◽  
Forage Species ◽  
In The Beginning ◽  
Almost All ◽  
Selection Of

AbstractThe inland prawn genus Macrobrachium Bate, 1868, is supposed to have originated from marine ancestors sometime in the beginning of the Pleistocene and since then its members have invaded freshwaters to different degrees. As such, these prawns are found to occupy almost all types of aquatic bodies right from purely marine through estuarine, riverine to impounded waters. Consequently, they have evolved various types of developmental patterns. Based on information available on more than 40 species, three basic types of larval developmental patterns can abe recognized in this genus viz., Prolonged or Normal Type (with 8 to 20 stages), Partially Abbreviated Type (with 2 or 3 stages) and Completely Abbreviated Type (with only 1 stage). However, there are several species showing transitional developmental patterns. Thus, the process of freshwaterization seems to be still continuing in the genus. Incidentally, the above knowledge can be applied in prawn culture as a basis for selection of a suitable candidate for forage species.

scholarly journals METACOMMUNICATION DISCOURSE SPECIFICS OF TV/RADIO BROADCASTS

2021 ◽  
Vol 1 (11(79)) ◽  
pp. 60-63
Author(s):  
Yaroslava Gnezdilova
Keyword(s):  
Quantitative Analysis ◽  
Information Transfer ◽  
Media Discourse ◽  
Visual Channel ◽  
Oral Speech ◽  
In The Beginning ◽  
Almost All

The article discovers discourse-specific characteristics of metacommunication, typical of TV/radio broadcasts. It identifies that TV/radio discourse belongs to oral media discourse that uses audio (and visual) channel of information transfer. The study marks the realization of six main types of metacommunication that have been introduced by the corresponding groups of meta-means, called phatic, regulative, referential, reflective, cohesive and modal, in TV/radio discourse in order to establish its metacommunication discourse-specific characteristics and to indicate "regular meta-means of oral media discourse". Based on the quantitative analysis, the article confirms that metacommunication specifics of TV/radio discourse is in its regulative character, and, consequently, almost all possible patterns of accentuating (denoting appeals, intentions, intensifications, degree, as well as attracting or affecting) and commentating (denoting confirmations, disagreements, distancing, explanations, generalizations, comparatives and conditions, confessions etc.) means are realized there. It also proves that the second most important in TV/radio discourse is a phatic metacommunication due to the host’s use of contact-establishing, contact-maintaining and contact-terminating meta-means. A special attention has been paid to the study of the same phatic means used in the beginning and at the end of the program. The research specifies that referential metacommunication is least typical of TV/radio discourse because the spontaneity of oral speech does not presuppose careful recollection of word-to-word citations, their authors etc.

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