scholarly journals Brittle Deformation in the Neoproterozoic Basement of Southeast Brazil: Traces of Intraplate Cenozoic Tectonics

Geosciences ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 270
Author(s):  
Marcos Roberto Pinheiro ◽  
Paola Cianfarra

The basement of southeast Brazil is traditionally interpreted as the result of Neoproterozoic and early Paleozoic orogenic cycles. Wide regions of the Atlantic Plateau (southeast Brazil) are characterized by rocks and tectonic structures of Precambrian age. According to the classical literature, these regions have not been affected by tectonics since the Miocene, despite the fact that they rest close to Cenozoic basins, which have suffered recent tectonic deformation. The objective of this research is to evaluate the role of neotectonics in the Atlantic Plateau. This task is accomplished through a multiscalar approach which includes lineament domain analysis from regionally sized digital elevation models and structural geology field surveys. Lineaments are automatically detected and statistically analyzed. Azimuthal analyses of data on faults and fractures by a polynomial Gaussian fit enables the identification of the main structural trends. Fault-slip direct inversion by means of the original Monte Carlo approach allows one to compute the multiple paleostresses that produced the measured fault population. The results show the presence of a principal ENE–WSW lineament domain, related to an old shear zone possibly reactivated since the Miocene. One of the paleostresses computed from fault-slip inversion is in agreement with the neotectonic stress-field proposed by other authors.

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1499
Author(s):  
Davide Fronzi ◽  
Francesco Mirabella ◽  
Carlo Cardellini ◽  
Stefano Caliro ◽  
Stefano Palpacelli ◽  
...  

The interaction between fluids and tectonic structures such as fault systems is a much-discussed issue. Many scientific works are aimed at understanding what the role of fault systems in the displacement of deep fluids is, by investigating the interaction between the upper mantle, the lower crustal portion and the upraising of gasses carried by liquids. Many other scientific works try to explore the interaction between the recharge processes, i.e., precipitation, and the fault zones, aiming to recognize the function of the abovementioned structures and their capability to direct groundwater flow towards preferential drainage areas. Understanding the role of faults in the recharge processes of punctual and linear springs, meant as gaining streams, is a key point in hydrogeology, as it is known that faults can act either as flow barriers or as preferential flow paths. In this work an investigation of a fault system located in the Nera River catchment (Italy), based on geo-structural investigations, tracer tests, geochemical and isotopic recharge modelling, allows to identify the role of the normal fault system before and after the 2016–2017 central Italy seismic sequence (Mmax = 6.5). The outcome was achieved by an integrated approach consisting of a structural geology field work, combined with GIS-based analysis, and of a hydrogeological investigation based on artificial tracer tests and geochemical and isotopic analyses.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tiziana Sgroi ◽  
Alina Polonia ◽  
Graziella Barberi ◽  
Andrea Billi ◽  
Luca Gasperini

AbstractThe Calabrian Arc subduction-rollback system along the convergent Africa/Eurasia plate boundary is among the most active geological structures in the Mediterranean Sea. However, its seismogenic behaviour is largely unknown, mostly due to the lack of seismological observations. We studied low-to-moderate magnitude earthquakes recorded by the seismic network onshore, integrated by data from a seafloor observatory (NEMO-SN1), to compute a lithospheric velocity model for the western Ionian Sea, and relocate seismic events along major tectonic structures. Spatial changes in the depth distribution of earthquakes highlight a major lithospheric boundary constituted by the Ionian Fault, which separates two sectors where thickness of the seismogenic layer varies over 40 km. This regional tectonic boundary represents the eastern limit of a domain characterized by thinner lithosphere, arc-orthogonal extension, and transtensional tectonic deformation. Occurrence of a few thrust-type earthquakes in the accretionary wedge may suggest a locked subduction interface in a complex tectonic setting, which involves the interplay between arc-orthogonal extension and plate convergence. We finally note that distribution of earthquakes and associated extensional deformation in the Messina Straits region could be explained by right-lateral displacement along the Ionian Fault. This observation could shed new light on proposed mechanisms for the 1908 Messina earthquake.


Geology ◽  
2019 ◽  
Vol 47 (12) ◽  
pp. 1127-1130 ◽  
Author(s):  
Gabriel G. Meyer ◽  
Nicolas Brantut ◽  
Thomas M. Mitchell ◽  
Philip G. Meredith

Abstract The so-called “brittle-ductile transition” is thought to be the strongest part of the lithosphere, and defines the lower limit of the seismogenic zone. It is characterized not only by a transition from localized to distributed (ductile) deformation, but also by a gradual change in microscale deformation mechanism, from microcracking to crystal plasticity. These two transitions can occur separately under different conditions. The threshold conditions bounding the transitions are expected to control how deformation is partitioned between localized fault slip and bulk ductile deformation. Here, we report results from triaxial deformation experiments on pre-faulted cores of Carrara marble over a range of confining pressures, and determine the relative partitioning of the total deformation between bulk strain and on-fault slip. We find that the transition initiates when fault strength (σf) exceeds the yield stress (σy) of the bulk rock, and terminates when it exceeds its ductile flow stress (σflow). In this domain, yield in the bulk rock occurs first, and fault slip is reactivated as a result of bulk strain hardening. The contribution of fault slip to the total deformation is proportional to the ratio (σf − σy)/(σflow − σy). We propose an updated crustal strength profile extending the localized-ductile transition toward shallower regions where the strength of the crust would be limited by fault friction, but significant proportions of tectonic deformation could be accommodated simultaneously by distributed ductile flow.


2014 ◽  
Vol 2 (1) ◽  
pp. 20-25
Author(s):  
Ruba Abuamsha ◽  
Hajaj Hajjeh ◽  
Mazen Salman

The overwintering modes of E. necator were studied on Palestinian vineyards, through observations on the differentiation and maturation of cleistothecia and on the occurrence of flag-shoots (deriving from overwintering mycelium) in vineyards. Field surveys were carried out in 17 vineyards for the presence of Flag shoots and cleistothecia, both forms were not observed. Genetic structure and composition of E. necator populations were investigated by application of already available SCAR (Sequence Characterized Amplified Region) primers specific for the "flag-shoot" and "ascospore" biotypes. These primers were used to evaluate the dynamics of the spatial and temporal distribution of the two biotypes, into fungal populations present in 8 vineyards, with different cultivars and spray histories, in various Palestinian districts (Hebron, Bethlehem, Jerusalem, Ramallah, Jericho, Nablus, Jenin, Tulkarm). 397 samples were analyzed by the uses of the primer pairs UnE-UnF in PCR reactions. All samples were found to be of the ascospore biotypes. This finding shows that the “flag shoot” biotype, appears soon after bud breaking and disappears later, while the “ascospore” biotype is more frequently associated to later infections and bunches damages. Such information would be helpful to understand the reasons underlying possible temporal evolution of the pathogen's populations in vineyards, and can have important implications for powdery mildew rationale control strategies.


Ecosystems ◽  
2020 ◽  
Author(s):  
Lily S. R. Tao ◽  
Gilbert C. S. Lui ◽  
Kingsley J. H. Wong ◽  
Tommy T. Y. Hui ◽  
Yanny K. Y. Mak ◽  
...  

Abstract Crustaceans were among the most valuable fishery resources in Hong Kong. However, the unrestricted and intensive use of different fishing gears, especially bottom trawling, has led to the depletion of commercially important crustaceans in Hong Kong since the 1980s. This study investigated whether commercial crustaceans recovered after the implementation of a permanent Hong Kong-wide trawl ban that began on December 31, 2012. Standardized field surveys were conducted using a commercial shrimp trawler at two sites in eastern and western waters of Hong Kong before (2004) and after the trawl ban (2013–2014 and 2015–2016) and two sites in southern waters after the trawl ban. Diversity, mean size, abundance, biomass and level of disturbance of commercial crustaceans from the three periods were investigated. The eastern waters exhibited an increased diversity of crustacean assemblages in Inner Tolo, and a higher abundance and biomass of crabs were detected in Outer Tolo after the trawl ban. Reduced disturbance, higher diversity in crustacean assemblages and greater abundance and biomass of predatory crabs were observed after the trawl ban in the outer estuary of western waters, and increased abundance and biomass of shrimp were detected in the inner estuary of western waters. No temporal or negative changes were detected in the southeast and southern waters of Lamma Island. The various responses of crustacean assemblages in Hong Kong waters revealed the critical role of complex interactions among multiple stresses, such as ongoing reclamation works, illegal trawling activities and increased fishing efforts using other (legal) fishing methods.


Author(s):  
Nurgun Vyacheslavovich Afanasev ◽  
Ul'yana Valer'evna Titova

The object of this research is the role of the comedy “Tieteybit” by N. D. Neustroev in cultural life of the Sakha Republic (Yakutia). The subject is the impact of modern creative industries upon cultural life of the region. On the example of Nikolay Denisovich Neustroev's comedy play “Tieteybit”, the authors examine the use of creative approaches towards preservation and popularization of cultural heritage of the Sakha people. It is noted that over the recent years, a major event in the development of spiritual culture and cultural life of the region overall has become the innovations introduced by the contemporaries in staging the Yakut comedies. Motifs of the comedy “Tieteybit” served as the prototype for staging the the first Yakut musical comedy, and even a film. A survey was conducted touching upon the following questions: are the innovations introduced in culture in form of a screen version of classical literature with the elements of innovation encourage the young generation to studying the Yakut cultural heritage?; what is the relevance of the work by N. D. Neustroev “Tieteybit”? The conclusions is made that in the XXI century, N. D. Neustroev's comedy “Tieteybit” has become one of the basics for the development of creative industry of the region. As an instrument for the development of regional culture, creative industry may play the strongest and highly effective role in the development of social life of the region.


2021 ◽  
Vol 46 (2) ◽  
pp. 93-104
Author(s):  
Наталья Тулякова ◽  
Наталья Никитина

Fantasy and science fiction genres extensively use imaginary settings and locations different from realistic ones but striving to look real. Arkady and Boris Strugatsky, pioneers of the science fiction genre in Russia, actively exploited the potential of both genres in their early tale, Monday starts on Saturday (1964), which combines features of the two space types. The present paper analyses the principles of creating ‘mago-space’ in the book. To do so, we look at the spatial organization of the events involved in the plot and the personages’ ideas regarding space. The research will enable us to clarify the role of space in conveying the authors’ message, which in this tale is quite explicit. We argue that the space changes significantly within the book, accompanying genre transformations and the development of the protagonist. Since the tale uses ‘mental sublocations’ as the main units of spatial organization, each part is determined by a certain type of cultural heritage. In the first part, it is the mental space of folklore and classical literature, in the second – that of mythology and science fiction, and in the final – philosophy and science. Mental spaces that coexist and follow various laws form a narrative which turns out to be a journey to the described present in the variety of its forms.


2021 ◽  
pp. 349-356
Author(s):  
Н.А. Чистякова

В последнее десятилетие резко изменилось отношение российской общественности к предпринимательству с негативного на нейтральное и даже позитивное. Для подтверждения предположения об изменении эмоционального статуса понятия «предпринимательство» автором был произведен соцопрос. Поскольку предположение об изменении статуса понятия «предпринимательство» подтвердилось, автор посредством историко-культурного анализа постарался объяснить причину изменения стереотипа. Акцент был сделан на роль произведений русской классической литературы в формировании общественного сознания. Кроме того, автор конкретизировал отраженный в классической литературе идеал русского предпринимателя. Конкретно, в статье проанализирован образ предпринимателя в русской классической литературе XIX века: разобраны литературные типы работников финансовой сферы, найдены положительные примеры, выявлены социально ответственные принципы подхода к делу. Для обеспечения большей объективности для анализа привлечены как эпические, так и драматические произведения. Автор выясняет, как в русской классической литературе отражаются проблемы личности предпринимателя, актуальные в настоящее время. В статье произведен сравнительный анализ «кодексов чести» предпринимателя – источников XIX и XXI века, – в которых раскрывается тема чести русского финансиста, его морального облика. В исследовании утверждается преемственность традиций в сфере предпринимательства, сформированных основной частью населения страны, жившего по законам Российской Империи, кроме того, обосновывается содержательная связь художественных и документальных источников и доказывается необходимость создания образа современного коммерсанта на основе принципов, отраженных в отечественной классике. In the last decade, the attitude of the Russian public towards entrepreneurship has changed dramatically from negative to neutral and even positive. To confirm the assumption about the change in the emotional status of the concept of «entrepreneurship», the author conducted a social survey. Since the assumption about the change in the status of the concept of «entrepreneurship» was confirmed, the author tried to explain the reason for the change in the stereotype through historical and cultural analysis. The emphasis was placed on the role of works of Russian classical literature in the formation of public consciousness. In addition, the author concretized the ideal of the Russian entrepreneur reflected in the classical literature. Specifically, the article analyzes the image of the entrepreneur in the Russian classical literature of the XIX century: the literary types of financial workers are analyzed, positive examples are found, and socially responsible principles of the approach to business are identified. To ensure greater objectivity, both epic and dramatic works are used for analysis. The author finds out how the Russian classical literature reflects the problems of the entrepreneur's personality that are currently relevant. The article presents a comparative analysis of the «codes of honor» of the entrepreneur-sources of the XIX and XXI centuries-which reveal the theme of the honor of the Russian financier, his moral image. The study confirms the continuity of traditions in the field of entrepreneurship, formed by the main part of the country's population, who lived according to the laws of the Russian Empire, in addition, substantiates the meaningful connection of artistic and documentary sources and proves the need to create an image of a modern merchant based on the principles reflected in the Russian classics.


2021 ◽  
Vol 30 (1) ◽  
pp. 78-89
Author(s):  
Nataliya O. Kryuchenko ◽  
Edward Ya. Zhovinsky ◽  
Petr S. Paparyga

he objective of the paper was determining biogeochemical peculiarities of ac- cumulation of chemical elements (Mn, Ni, Сo, V, Cr, Zr, Cu, Pb, Zn, Ba, P) by wild-grow- ing shrubs (stems and leaves) – bog bilberry (Vaccіnium uliginоsum), European blueberry (Vaccinium myrtillus L.), alpine juniper (J. communis subsp. alpina); perennial herbaceous plants (flowers and leaves) – common tormentil (Potentіlla erecta (L.) Hampe), willow gentian (Gentiana asclepiadea), true sedges (Carex); and trees (needles) of European silver fir (Abies alba) on nine plots in the Svy- dovets Massif of the Ukrainian Carpathians. The results we obtained based on field surveys (selection of samples of soil and vegeta- tion) and interpretation of their analysis allowed us to determine the total regional background of chemical elements in soils and ash of plants using emission spectral analysis. We assessed the total concentration of chemical elements in soils of the plots (least to highest): the Apshynets Ridge – the Herashaska Polonyna – Drahobratske Lake – the Svydovets stream – Apshynets Lake – Herashaske Lake – the Zhuravlyne Bog – Vorozheske Lake (group of small lakes) – Vorozheske Lake (large) and determined the dependence on type of soil and pH. We determined that for wild-growing herbaceous plants the biogeochemical activity of species increases in the following sequence: true sedges - willow gentian - common tormentil; for wild-growing shrubs (bog bilberry, European blueberry, alpine juniper) such a sequence is impossible to determine due to the great difference between the values on different plots. We determined the role of each plant as medicinal for treating microelement deficiency in Cu, Zn, Co. We determined that in the plot of the Herashaska Polonyna, the needles of alpine juniper contain a maximum amount of Zn and Co, the needles and leaves of bog bilberry – Cu, Zn, Co; the flowers and leaves of common tormentil by Apshynets Lake and European silver fir near the area of the Svydovets stream – Cu. We calculated the daily dose of each element according to species of plants to overcome microelementosis. The results of biogeochemical surveys may be the basis for determining and recommending plants as medicinal, and also of geochemical and biogeochemical monitoring studies.


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