Vertical distribution of PAHs during the evolution of permafrost peatlands of the European arctic zone

2020 ◽  
Vol 123 ◽  
pp. 104790
Author(s):  
Dmitriy Gabov ◽  
Evgenia Yakovleva ◽  
Roman Vasilevich
Tellus B ◽  
1993 ◽  
Vol 45 (2) ◽  
pp. 106-119 ◽  
Author(s):  
Petteri Taalas ◽  
Esko KyrÖ ◽  
Ari Supperi ◽  
Victoria Tafuri ◽  
Maximo Ginzburg

Tellus B ◽  
1993 ◽  
Vol 45 (2) ◽  
pp. 106-119 ◽  
Author(s):  
PETTERI TAALAS ◽  
ESKO KYRO ◽  
ARI SUPPERI ◽  
VICTORIA TAFURI ◽  
MAXIMO GINZBURG

2021 ◽  
Author(s):  
Tatyana Shumilova

<p>The Kara astrobleme is one of the biggest meteoritic craters which is set at the Baydarata Bay of the Kara sea (European Arctic Zone, Russia). It is a result of the catastrophic impact event occurred close to the K/Т extinction. The Kara astrobleme is the largest European crater at the modern erosion level.  At present it is estimated with the diameter from rim to rim about 65 km. While, some scientists have proposed its larger initial size – up to 120 km diameter, but no any well presented proof has been provided for the hypothesis. In 2015-2019 we have provided wide geological observations at the Kara crater and the near-set Ust`-Kara area (UKA) impactites. We have found for the first time that the UKA impactites, described in earlier Russian scientists publications as a synchronic independent crater of the same bolide, can be presented with bottom-flow impactites from the Kara crater (Shumilova et al., 2020). The found bottom-flow impactites abundant with belt-like impact melt bodies enriched in coesite and liquation structures similar to the Kara UHPHT vein and vein-like melt bodies with UHPHT impact glasses. Thus, they belong to UHPHT impactites. According to our air-bird view observations and impactites outcrops description at the UKA we support the hypothesis of the larger Kara crater getting 100-120 km in diameter of the initially originated size. Such giant meteorite event should be followed by catastrophic effects at the planet level, such as mass extinction. The present accepted Kara impact event age followed by the most recent measurements by <sup>40</sup>Ar-<sup>39</sup>Ar method is equal to 70.3 ± 2.2 Ma (Trieloff et al., 1998), that is a bit earlier than the Cretaceous/Tertiary boundary (K/Т) mass extinction at 66 Ma. But, previously, Kara age has been proposed by 65.7 Ma as a probable K/T impact (Kolesnikov et al., 1988; Nazarov et al., 1992). According to different data, the Kara event age lies within the range from 60 to 81 Ma (Masaitis & Mashchak, 1982; Nazarov et al., 1989; Kolesniov et al., 1990; Koeberl et al., 1990). It is clear that the accuracy of the age measurements depend on the quality of the studied samples, including their crystallinity, velocity of impact melt cooling and alteration, and from the used type of a method. By the moment, we have found out “in situ” crystallized zircons within the just discovered real UHPHT impact melt glasses (Shumilova et al., 2018, 2020). The UHPHT glasses do not have any alteration, thus, they can be used for accurate age measurements. Taking a future possibility for more accurate age analysis in the nearest future we can propose a correct vision of the possibility of the giant Kara influence to K-T mass extinction or other ecological effects. In any case following to the giant size of the Kara event touched the sedimentary rocks abundant with black shales and carbonates, which should be a result of essential atmospheric changes. The study has been supported by the Russian Science Foundation project #17-17-01080.</p>


2020 ◽  
Vol 10 (1) ◽  
pp. 66-69
Author(s):  
Natalia Zhavoronkova ◽  
Vyacheslav Agafonov

The article is devoted to the study of modern theoretical and legal problems of ensuring biological security in the Arctic zone of the Russian Federation. The published Draft of Federal law No. 850485-7“On biological security of the Russian Federation”provides an opportunity to take a closer look at the problem of legal provision of biological security in relation to the most vulnerable ecosystems, and, first of all, the Arctic. The article considers the most important features and potential risks of the Arctic zone of the Russian Federation of critical importance from the point of view of biological hazards, the features (specificity) of biological safety problems from the point of view of organizational-legal features and, in particular, from the perspective of environmental law. It is proved that, given the special situation of the Arctic zone of the Russian Federation, in addition to the base Federal law“About biological safety” required a specific law on biological and ecological safety of the Arctic zone of the Russian Federation, which should be generated on a slightly different model than the draft Federal law «On biological safety”, to wear the most specific, applied nature.


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