scholarly journals Geological features and the first isotopic data of volcanic rocks in the Iset river basin, East-Urals megazone

2021 ◽  
Vol 1 ◽  
pp. 55-64
Author(s):  
Vasiliy Stanislavovich CHERVYAKOVSKIY
Keyword(s):  
River Basin ◽  
Large Scale ◽  
Volcanic Rocks ◽  
Early Carboniferous ◽  
Geological Structure ◽  
Geological Mapping ◽  
Isotopic Age ◽  
Isotopic Dating ◽  
Sedimentary Deposits ◽  
Tectonic Contact

Relevance of the work. The Iset river basin contains the most extensive outcrops of volcanogenic formations of the Beklenishchevsky complex of the East Ural megazone, the age of which is determined as Early Carboniferous by the ratio of volcanic rocks with faunistically characterized sedimentary deposits. Volcanics here compose flows of andesite-basaltic and andesitic lavas and lava breccias. There are no geochronological dates specifying the age of the rocks, which makes it difficult to assess their role in the formation of the megazone. Therefore, isotopic dating of these formations is very important. Methods. The U – Pb age and data on the geochemistry of zircons were obtained by laser ablation (LA – ICP – MS). Purpose of the research is to study the features of the geological structure, the material composition of volcanic rocks in the Iset river basin, the geochemistry of zircons from andesites and the determination of their isotopic age. Results of the work and the scope of their application. Lava flows of andesites and basaltic andesites with minor amounts of basalts and dacites have tectonic contact with sedimentary rocks of the Early Carboniferous age. The distribution of rare elements in volcanics is typical of supra-subduction formations. Zircons in andesites are represented by prismatic and isometric crystals. Prismatic differences in the nature of the distribution of REE and the content of Li, Ti, Sr, Th, U refer to zircons of magmatic genesis, isometric – to “hydrothermal”. According to the U / Yb – Y ratios, the former correspond to the zircons of the ocean floor, while the latter are related to the continental ones. Isotopic dating of zircons from andesites was carried out for the first time. Their age was 311 million years. The data can be used in geological mapping, as well as in the compilation of large-scale geodynamic maps and diagrams. Conclusions. Volcanic rocks in the Iset river basin were formed in supra-subduction continental-marginal geodynamic conditions that took place in the Urals in the Carboniferous. The obtained value of the age of zircons from andesites, possibly, fixes the stage of their transformation. Keywords: East-Ural megazone, volcanic rocks, zircon, isotopic age.

scholarly journals GEOLOGY AND PETROGRAPHY OF THE VEDEL ISLANDS (WILHELM ARCHIPELAGO, WEST ANTARCTICA)

2020 ◽  
pp. 18-27
Author(s):  
O. Mytrokhyn ◽  
V. Bakhmuto
Keyword(s):  
Large Scale ◽  
Deep Level ◽  
Geological Structure ◽  
Geological Mapping ◽  
Small Island ◽  
West Antarctica ◽  
Mode Of Occurrence ◽  
Plutonic Rocks ◽  
The Antarctic ◽  
Tectonic Exhumation

The Vedel Islands are a small island group that is part of the Wilhelm archipelago in the West Antarctica. They are located near the Graham Coast of the Antarctic Peninsula at a distance of 12 km from Akademik Vernadsky Ukrainian Antarctic Station. Until recently, the Vedel Islands were a "white spot" on all existing geological maps. In 2019, during the seasonal work of the 24th Ukrainian Antarctic expedition, the authors first carried out field geological researches on the Vedel Islands. The main goal of the geological survey was reconnaissance and large-scale geological mapping. The general ideas about the geological structure of the study area were developed by further processing of the collected materials. The preliminary data about the mode of occurrence, the geological ages, the petrographic peculiarities and the ore potential of the local rocks were also obtained. It was first established that multiple-aged intrusive-magmatic formations take part in the geological structure of the Vedel Islands. The intermediate compositions of the plutonic rocks namely the diorites and quartz diorites are the most common among them. The gabbroids and the tonalites are less common. The least common ones are hypabyssal and subvolcanic dike rocks namely microdiorites and diabases. The plutonic rocks were formed in at least three intrusive phases with a homodromous order of their intrusions. The most ancient among them are gabbroids. The Early Cretaceous age for their formation is assumed by analogy with the petrographically similar rocks of the Tuxen-Rasmussen layered gabbroid intrusion (TRGI). The tonilites are the youngest plutonic rocks on the Vedel Islands. It is assumed that their formation at a deep level took place in the Late Cretaceous, although their tectonic exhumation and the final erosion outcropping occurred in the Paleogene and ended in the Neogene. In the process of the exhumation, the plutonic rocks were intruded by hypabyssal dikes of microdiorites. The youngest subvolcanic diabase dykes intruded the tonalites supposedly after their complete erosion outcropping i. e. in Neogene or even Quaternary. Like TRGI and other layered gabbroid intrusions of the Wilhelm archipelago, the Vedel island gabbroids contain iron-titanium oxide-ore and copper-silicate mineralization, which requires further study. The additional researches are also needed to clarify the age, origin, petrography and mineralogy of the numerous veins of aplite-pegmatoid granite which intrude gabbroids and diorites on the Vedel Islands.

scholarly journals Geology, physical-chemical and geodynamic conditions for the formation of Sokolovsk and Krasnokamensk granitoid massifs (South Ural)

Georesursy ◽  
2021 ◽  
Vol 23 (1) ◽  
pp. 85-93
Author(s):  
Vladimir I. Snachev ◽  
Aleksandr V. Snachev ◽  
Boris A. Puzhakov
Keyword(s):  
Early Carboniferous ◽  
Southern Urals ◽  
Geological Structure ◽  
Rift System ◽  
Second Phase ◽  
The Southern Urals ◽  
Lower Carboniferous ◽  
Sedimentary Deposits ◽  
Granite Formation ◽  
Physical Chemical

The article describes the geological structure of the Sokolovsk and Krasnokamensk massifs located in the central part of the Western subzone of the Chelyabinsk-Adamovka zone of the Southern Urals. They are of Lower Carboniferous age and break through the volcanogenic-sedimentary deposits of the Krasnokamensk (D3kr) and Bulatovo (S1-D1bl) strata. It was found that these intrusions belong to the gabbro-syenite complex and are composed of gabbroids (phase I) and syenites, quartz monzonites, less often monzodiorites (phase II). The rocks of the second phase predominate (90–95%). Gabbros belong to the normal alkaline series of the sodium series and are close to tholeiitic mafic rocks, the formation of which is associated with riftogenic structures; syenites correspond to moderately alkaline series with K-Na type of alkalinity. It has been proved that in terms of their petrographic, petrochemical, geochemical, and metallogenic features (content of TiO2, K2O, Na2O, Rb, Sr, distribution of REE, the presence of skarn-magnetic mineralization), the rocks of the massifs under consideration undoubtedly belong to the gabbro-granite formation. Crystallization of the Sokolovsk and Krasnokamensk intrusions occurred at a temperature of 880–930 °С in the mesoabyssal zone at a depth of about 7–8 km (P = 2.2–2.4 kbar). At the postmagmatic stage, the transformation parameters of the initially igneous rocks were, respectively, T = 730–770 °C, P = 4.0–4.2 kbar. The fact that these massifs belong to the gabbro-granite formation makes it possible to include them, together with Bolshakovsk, Klyuchevsky, Kurtmaksky and Kambulatovo, into the Chelyabinsk-Adamovka segment of the South Ural Early Carboniferous rift system.

scholarly journals Groundwater quality in Ponjong Karst, Gunungkidul Regency, Special Region of Yogyakarta

2020 ◽  
Vol 1 (1) ◽  
pp. 7-11
Author(s):  
Avellyn Shintya Sari ◽  
Sari Bahagiarti K ◽  
Suharsono Suharsono ◽  
C Prasetyadi
Keyword(s):  
Volcanic Rocks ◽  
Active Volcano ◽  
Research Area ◽  
Geological Structure ◽  
Groundwater Exploration ◽  
Geological Mapping ◽  
Karst Area ◽  
Aquifer System ◽  
Aquifer Systems ◽  
Geological Conditions

The hydrogeological condition of a region is determined by the type of lithology, morphology, and subsurface conditions where the condition is very helpful in the study of groundwater exploration. Especially when we encounter interesting geological conditions when the groundwater exploration in the karst area in which volcanic rocks are resulting from the activities of the active volcano in the past. Groundwater exploration at Ponjong area and surrounding does have its special characteristics, because it has 2 different rock characteristics where the northern part of the research area in the form of a karst area (limestone of Wonosari Formation) while the southern part is an area of ancient volcanoes with dominant volcanic rocks from Wuni Formation, As for the research on the above and subsurface research area where the research is conducted based on surface geology mapping, geoelectric data collection, and groundwater sampling. Geological mapping includes geomorphological data, stratigraphy, and geological structure. The aquifer system of the research area can be divided into two systems, inter-grain aquifer systems, and fracture aquifer systems. Overall quality groundwater in the research area is quite good. Ponjong District there are mining activities that have resulted in changes in the land use system in the area. This can cause changes in the water surplus in the area due to the changing catchment area.

scholarly journals Uranium-Lead by Monacite Geochronology of Granites Distributed in the Middle Current of ihe River Ros (Ros-Tikich Megablock Ukrainian Shield)

2021 ◽  
pp. 89-93
Author(s):  
Т.I. Dovbush ◽  
◽  
L.M. Stepaniuk ◽  
О.V. Ziultsle ◽  
Т.B. Yaskevych ◽  
...  
Keyword(s):  
Geological Structure ◽  
Ukrainian Shield ◽  
Isotopic Age ◽  
Isotopic Dating ◽  
Leading Role ◽  
The Village ◽  
Good Agreement

Granitoids play a leading role in the geological structure of the Ros-Tikich megablock. The rocks of the Ros-Tikich series, which form the supercrystalline base here, have survived among the granitoids only in the form of some remnants of different sizes. In the coastal outcrops of the middle course of the river Ros (east of Bila Tserkva) and in the quarries located near the river, the most common are two-feldspar granitoids, isolated as part of two complexes – Uman and Stavyshche. Plagiogranitoids and supercrustal rocks have survived among them in the form of separate fragments. Of the accessory uranium-containing minerals, zircon and titanite are present in two-field spar granites, and monazite was found in single samples of granites in which titanite was absent. The age of obscure porphyry-like granite discovered by the Ostrivsk quarry – 2063.5 ± 1.2 million years and uniformgrained granite, distributed in the quarry of the village of Bovkun – 2042.5 ± 8.6 million years. The obtained values of the isotopic age of these granites are in good agreement with the results of uranium-lead isotopic dating of zircons from twofeldspar granites of the Ros-Tikich megablock (1990-2080 million years). This allows us to propose to combine the granites of the Stavyshche and Uman complexes into one Paleoproterozoic complex.

The Chingandzha flora of the Okhotsk-Chukotka volcanic belt

Palaeobotany ◽  
2019 ◽  
Vol 10 ◽  
pp. 13-179
Author(s):  
L. B. Golovneva
Keyword(s):  
River Basin ◽  
Volcanic Belt ◽  
Flowering Plants ◽  
Sedimentary Deposits ◽  
North East ◽  
The North ◽  
Magadan Region ◽  
Chukotka Volcanic Belt ◽  
Systematic Composition ◽  
Coastal Lowlands

The Chingandzha flora comes from the volcanic-sedimentary deposits of the Chingandzha Formation (the Okhotsk-Chukotka volcanic belt, North-East of Russia). The main localities of the Chingandzha flora are situated in the Omsukchan district of the Magadan Region: on the Tap River (basin of the middle course of the Viliga River), on the Kananyga River, near the mouth of the Rond Creek, and in the middle reaches of the Chingandzha River (basin of the Tumany River). The Chingandzha flora includes 23 genera and 33 species. Two new species (Taxodium viligense Golovn. and Cupressinocladus shelikhovii Golovn.) are described, and two new combinations (Arctopteris ochotica (Samyl.) Golovn. and Dalembia kryshtofovichii (Samyl.) Golovn.) are created. The Chingandzha flora consists of liverworts, horsetails, ferns, seed ferns, ginkgoaleans, conifers, and angiosperms. The main genera are Arctop teris, Osmunda, Coniopteris, Cladophlebis, Ginkgo, Sagenoptepis, Sequoia, Taxodium, Metasequoia, Cupressinocladus, Protophyllocladus, Pseudoprotophyllum, Trochodendroides, Dalembia, Menispermites, Araliaephyllum, Quereuxia. The Chingandzha flora is distinct from other floras of the Okhotsk-Chukotka volcanic belt (OCVB) in predominance of flowering plants and in absence of the Early Cretaceous relicts such as Podozamites, Phoenicopsis and cycadophytes. According to its systematic composition and palaeoecological features, the Chingandzha flora is similar to the Coniacian Kaivayam and Tylpegyrgynay floras of the North-East of Russia, which were distributed at coastal lowlands east of the mountain ridges of the OCVB. Therefore, the age of the Chingandzha flora is determined as the Coniacian. This flora is assigned to the Kaivayam phase of the flora evolution and to the Anadyr Province of the Siberian-Canadian floristic realm. The Chingandzha flora is correlated with the Coniacian Aleeky flora from the Viliga-Tumany interfluve area and with other Coniacian floras of the OCVB: the Chaun flora of the Central Chukotka, the Kholchan flora of the Magadan Region and the Ul’ya flora of the Ul’ya Depression.

scholarly journals Using the Global Hydrodynamic Model and GRACE Follow-On Data to Access the 2020 Catastrophic Flood in Yangtze River Basin

2021 ◽  
Vol 13 (15) ◽  
pp. 3023
Author(s):  
Jinghua Xiong ◽  
Shenglian Guo ◽  
Jiabo Yin ◽  
Lei Gu ◽  
Feng Xiong
Keyword(s):  
River Basin ◽  
Hydrodynamic Model ◽  
Yangtze River ◽  
Large Scale ◽  
Yangtze River Basin ◽  
The Yangtze River ◽  
Ecosystem Monitoring ◽  
Catastrophic Flood ◽  
Basin Scale ◽  
The Yangtze River Basin

Flooding is one of the most widespread and frequent weather-related hazards that has devastating impacts on the society and ecosystem. Monitoring flooding is a vital issue for water resources management, socioeconomic sustainable development, and maintaining life safety. By integrating multiple precipitation, evapotranspiration, and GRACE-Follow On (GRAFO) terrestrial water storage anomaly (TWSA) datasets, this study uses the water balance principle coupled with the CaMa-Flood hydrodynamic model to access the spatiotemporal discharge variations in the Yangtze River basin during the 2020 catastrophic flood. The results show that: (1) TWSA bias dominates the overall uncertainty in runoff at the basin scale, which is spatially governed by uncertainty in TWSA and precipitation; (2) spatially, a field significance at the 5% level is discovered for the correlations between GRAFO-based runoff and GLDAS results. The GRAFO-derived discharge series has a high correlation coefficient with either in situ observations and hydrological simulations for the Yangtze River basin, at the 0.01 significance level; (3) the GRAFO-derived discharge observes the flood peaks in July and August and the recession process in October 2020. Our developed approach provides an alternative way of monitoring large-scale extreme hydrological events with the latest GRAFO release and CaMa-Flood model.

Mechanics Research on Rock Stress and Deformation of Lancang River Canyon's Large - Scale Dumping Deformation

2013 ◽  
Vol 353-356 ◽  
pp. 318-323
Author(s):  
Song Ye ◽  
Yu Sheng Li ◽  
Qian Guo
Keyword(s):  
Large Scale ◽  
Geological Structure ◽  
Deformation Characteristics ◽  
Deep Part ◽  
Trailing Edge ◽  
Geological Surveys ◽  
Depth Analysis ◽  
Numerical Simulation Methods ◽  
Complex Geological Structure ◽  
Stress And Deformation

This article is based on geological surveys combined with finite element and discrete element numerical simulation methods. In-depth analysis of the complex geological structure, deformation characteristics and stress - deformation problems of dumping rock, we clarify different deformation characteristics of deformable landslide inside, at the bottom and the deep part of trailing edge, and demonstrate the deformation will gradually shift from dumping to shear slip. Potential deformation failure mode will be dumped into the whole sliding - tension, which is controlled by the bottom broken belt, and potential deformation is mainly subject to the bottom fault F207-3 of deformed rock and the dumping broken belt at the deep part of trailing edge.

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