scholarly journals LOCALIZATION CONDITIONS AND THE GOLD CONTENT OF THE SCARNS OF ZYGYRKOL ORE ZONE (KABARDINOBALKARSKAYA REPUBLIC)

2017 ◽  
Author(s):  
С.Г. Парада ◽  
В.В. Столяров
Keyword(s):  
Reverse Fault ◽  
Optimum Level ◽  
Gold Content ◽  
Minimum Level ◽  
Lower Section ◽  
The North ◽  
Geological Conditions ◽  
Localization Conditions ◽  
North Western ◽  
Gold Bearing

Охарактеризованы геологические условия локализации золотоносных скарнов Зыгыркольской рудной зоны, выявленных при участии авторов в последние годы на Северном фланге Тырныаузского рудного узла. Установлено длительное (с позднего палеозоя) развитие деформаций в пределах Гитче-Тырныаузского рудного поля, и что к формированию продуктивной на золото Зыгыркольской рудной зоны привели вертикальное растяжение и взбросо-сдвиговые деформации альпийского этапа. Выделены четыре участка развития золотоносных скарнов. Раскрыты характер и степень их золотоносности. Они определяются уровнем денудационного среза Зыгыркольской зоны, которая воздымается в северо-западном направлении под меньшим углом, чем возвышается рельеф, что приводит к уходу под рельеф оптимального рудоносного уровня. Оптимальным уровнем среза обладает Нижний участок, где наиболее золотоносные скарны выходят на земную поверхность. Минимальным уровнем среза обладает Перевальный участок, где продуктивные на золото скарны располагаются на 100?200 м ниже земной поверхности. Are described the geological conditions for localization of the gold-bearing Zygyrkol ore zone scarns, revealed with the participation of the authors in recent years on the northern flank of Tyrnyauz ore unit. Is established the prolonged (from the late Paleozoic period) development of deformations within the limits of Gitche-Tyrnyauz ore field, and that to shaping of productive to gold Zygyrkol ore zone gave vertical tension and the reverse fault-shift deformations of Alpine stage. Four sections of the development of gold-bearing scarns are isolated. Nature and degree of their gold content are opened. They are determined by the level of the Zygyrkol zone denudation shear, which rises up in the North Western direction hearth by smaller angle than is raised relief, which leads to the withdrawal under the relief of optimum ore-bearing level. The lower section, where the gold-bearing scarns leave to the earth’s surface, possesses the optimum level of shear. The crossing section, where the scarns productive to gold are located on 100?200 m lower than earth’s surface, possesses the minimum level of shear.

scholarly journals Water tracks in the lower Lena River basin

2020 ◽  
Vol 163 ◽  
pp. 04007
Author(s):  
Anna Tarbeeva ◽  
Lyudmila Lebedeva ◽  
Vladimir Efremov ◽  
Vladimir Shamov ◽  
Olga Makarieva
Keyword(s):  
Active Layer ◽  
Surface Flow ◽  
Water Levels ◽  
Storm Event ◽  
Lena River ◽  
The North ◽  
Geological Conditions ◽  
North Western ◽  
Cryogenic Processes ◽  
Permafrost Regions

In the permafrost regions, where water filtration zone is limited by the shallow active layer, the surface flow forms a network of hollows, called «water tracks», oriented along the slope gradient. Water tracks are clearly distinguished on satellite images, but poorly defined in the field. The pattern of the water tracks network depends on geomorphological position, permafrost and geological conditions and dominant cryogenic processes. Surface flow could occur in the water tracks during the snowmelt and heavy rains, when the soil is entirely frozen or fully saturated by water. In dry periods, the water tracks form retention zones due to low filtration rates and significant capacity of thawed soil beneath the troughs. Our study of water tracks in the north-western Yakutia showed the changes of their morphology from upstream towards downstream. The water levels in the water tracks have a pronounced diurnal course in reverse phase to the water temperature variation. They are related to diurnal ground thawing dynamics. Hydrology of water tracks depends on the peat thickness, active layer properties and lithology. Water tracks formed by rubble rocks respond to a storm event with rapidly increasing water level. The deeper thawing layer, the smoother water levels rise and decrease.

scholarly journals The role of geological conditions in the disintegration of historical structures on the escarpment of the Lower Vistula Valley, on the example of Chełmno (Poland)

2017 ◽  
Vol 12 (1) ◽  
pp. 83-91
Author(s):  
Ewa Labak-Mechowska ◽  
Michał Dąbrowski
Keyword(s):  
Geological Structure ◽  
Tourist Destination ◽  
Historical Structures ◽  
The North ◽  
Geological Conditions ◽  
North Western

Abstract Chełmno is a town in the north-western part of the Chełmno Lakeland. It is one of few towns in Poland to have fully preserved its medieval defensive walls. Its touristic and natural environs make it a popular tourist destination. The town’s location near the escarpment of the Vistula valley mean that the preserved historical structures (including the defensive walls) are under threat. A few years ago a buttress became detached and two sections of the defensive walls collapsed. One part was rebuilt (the site where the studies were conducted), while the second part remains unrestored. Bricks are also progressively coming away. This situation may be the result of several factors, although the authors claim that the most important are the geological structure and the wall foundations (which are shallow, at a depth of 1-2 m, with the wall having been built up higher in the 16th century).

Caractéristiques pétrographiques et géochimiques de la minéralisation aurifère à la mine Elder, Abitibi, Québec

1990 ◽  
Vol 27 (12) ◽  
pp. 1637-1650 ◽  
Author(s):  
R. Gaulin ◽  
P. Trudel
Keyword(s):  
Earth Element ◽  
Volcanic Rocks ◽  
Reverse Fault ◽  
Gold Content ◽  
Mafic Dike ◽  
Gold Mines ◽  
Quartz Veins ◽  
Gold Enrichment ◽  
Main Vein ◽  
Gold Bearing

The Elder deposit is located on the southeast border of the Flavrian Batholith, which intrudes the Blake River Group of archean volcanic rocks. The ore zone is composed of veins 1, 3, 5, and 4. The first three veins are a series of brecciated quartz veins having mean strike and dip of N72°E and 28°SE. Least important is vein 4, striking N20°W and dipping 28°NE. A reverse fault and a mafic dike are associated with the main vein 1, which occurs within trondhjemite in contact with hybrid rocks. The mafic dike represents an important metallotect. The ore zone is marked by abundant carbonates and pyrite, is slightly enriched in hematite and rutile, and is lightly depleted in sericite and chlorite. The mineralogical variation depends on CaO, MgO, CO2, S, TiO2, Fe2O3, MnO, and P2O5 enrichments and SiO2, Na2O, Al2O3, and H2Odepletions. A gold-bearing halo 8 m wide surrounds the ore zone. Seventy-nine per cent of the gold grains are associated with pyrite; otherwise gold occurs mostly as inclusions in the plagioclase matrix. Gold enrichment and rare-earth-element (REE) losses in the ore zone are similar to those observed in other Abitibi gold mines. In veins 1, 3, and 5, divergences in Ag and As enrichments, gold content, and REE concentrations suggest different ore-forming solutions.[Journal Translation]

scholarly journals Seismic Structural Analysis of the Alam-El Bueib Formation, Qasr Oil Field, North Western desert, Egypt

2019 ◽  
pp. 20-25
Author(s):  
Farouk I Metwalli ◽  
Mahmoud S Yousif ◽  
Nancy H El Dally ◽  
Ahmed S Abu El Ata
Keyword(s):  
Lower Cretaceous ◽  
Oil Field ◽  
Western Desert ◽  
Normal Faults ◽  
Reverse Fault ◽  
The South ◽  
Late Mesozoic ◽  
Clastic Rocks ◽  
The North ◽  
North Western

The Qasr oil and gas Field is located in the north western desert of Egypt. It belongs to the southeastern part of the Lower Jurassic-Cretaceous Shushan Basin. The Lower Cretaceous Alam-El Bueib formation composed of clastic rocks with noticeable carbonate proportions, and forms multiple oil-bearing sandstone reservoirs in Qasr field. The study aims to define and analyze the Surface and subsurface structural features which are a key issue in assessing reservoir quality. Through this integrated approach, one may be able to identify lithologies and fluids in this region and provide possibly new hydrocarbon fairways for exploration. For this purpose, seismic and well data were interpreted and mapped in order to visualize the subsurface structure of the Cretaceous section. Results show the effect of NE-SW, NW-SE, and E-W trending normal faulting on the Lower Cretaceous Alam-El Bueib formation and is extended to the Upper Cretaceous Abu Roash Formation. The effect of folding is minimal but can be detected. These normal faults are related to the extensional tectonics which affected the north western desert of Egypt during the Mesozoic. One reverse fault is detected in the eastern part and is related mostly to the inversion tectonics in the Late Mesozoic. The depth structure contour maps of the Alam-El Bueib horizons (AEB-1, AEB-3A, and AEB-3D) show several major normal faults trending NE-SW and minor normal faults trending NW-SE. One larger branching normal fault trending E-W and lies to the south of the study area. These step-normal faults divide the area into a number of tilted structural blocks which are shallower in the south and deepen to the north. The area of study was most probably affected by E-W trending normal faults during the opening of the Atlantic Ocean in the Jurassic. Later right-lateral compression resulted from the movement of Laurasia against North Africa, changed their trend into NE-SW faults with minor NW-SE trending folds. These compressive stresses are also responsible for the reverse faulting resulted by inversion in the Late Mesozoic.

scholarly journals Engineering and geological conditions of the north-western territory of Makhachkala due to flooding

2021 ◽  
pp. 45-54
Author(s):  
В.М. Кондаков ◽  
С.А. Мамаев ◽  
М.А. Мусаев ◽  
А.С. Мамаев
Keyword(s):  
Chemical Composition ◽  
Environmental Consequences ◽  
The North ◽  
Hydrogeological Parameters ◽  
Western Area ◽  
Geological Conditions ◽  
Caspian Lowland ◽  
Horizontal Type ◽  
North Western

Определение геоморфологических и геологических условий северо-западной площади г. Махачкалы, включая Новолакский район (Новострой), в связи с процессами засоления, осолонцевания и подтопления сельскохозяйственных земель. В настоящее время город интенсивно расширяется во все стороны. Особенно актуально изучение северо-западной территории г. Махачкалы в связи с подтоплением. Район относится к Прикаспийской низменности с отрицательными отметками рельефа. Отсутствие исследований по указанным проблемам может привести к нежелательным материальным и экологическим последствиям. В связи с подтоплением изменяются и несущие способности грунтов. Изменяются сейсмоакустические свойства грунтов, т.е. скорости распространения продольных (Vp) и поперечных (Vs) волн, а также соответствующие коэффициенты и декременты их поглощения. Цель работы. Определить границы слабо дренированных и весьма слабо дренированных зон, которые выявляют барражные участки территории, и гидрогеологические районы в зависимости от водопроводимости составных верхней и нижней толщ грунтов. Методы исследований. Сбор базы данных инженерно-геологических изысканий по химическому составу грунтовых вод и литологии покровных толщ грунтов. Сбор гидрогеологических параметров разных типов грунтов и гранулометрического состава песков целью интерпретации их фильтрационных свойств. Определение уклона рельефа местности с целью выявления зон дренированности территории. Результаты работы. Представлены таблицы химического состава грунтовых вод по 19-ти объектам и гидрогеологических условий площади по данным инженерно-геологических изысканий по 39-ти объектам, в том числе глубины залегания грунтовых вод, типа грунтов по сейсмичности, глубины залегания коренных пород, трех таксонов гидрогеологических районов, уклонов рельефа. Для выделенных гидрогеологических районов: для ГР-1 рекомендуется горизонтальный тип дренажа, для ГР-2 – вертикальный или комбинированный типы дренажа, для ГР-3 – подземный дренаж не эффективен. Указано о необходимости сейсмического микрорайонирования не только исследованного района, но и всего города Махачкалы, с перспективой дальнейшей застройки. Determination of the geomorphological and geological conditions of the north-western area of Makhachkala, including the Novolaksky district (Novostroy), in connection with the processes of salinization, alkalinization and flooding of agricultural lands. Currently, the city is intensively expanding in all directions. Particularly interesting is the study area of ​​the northwestern territory of Makhachkala due to flooding. It belongs to the Caspian lowland with negative relief marks. Lack of research on these problems can lead to undesirable material and environmental consequences. Due to flooding, the bearing capacity of the soil also changes. The seismoacoustic properties of soils change, i.e. the velocities of propagation of longitudinal (Vp) and transverse (Vs) waves, as well as the corresponding coefficients and decrements of their absorption. Aim.Determine the boundaries of poorly drained and very poorly drained zones, which reveal barrage areas of the territory, and hydrogeological areas, depending on the water permeability of the composite upper and lower soil strata. Methods. Collecting a database of geotechnical surveys on the chemical composition of groundwater and lithology of cover layers of soils. Collecting hydrogeological parameters of different types of soils and granulometric composition of sands in order to interpret their filtration properties. Determination of the slope of the terrain in order to identify the drainage zones of the territory. Results.Presented are tables of the chemical composition of groundwater for 19 objects and hydrogeological conditions of the area according to engineering and geological surveys for 39 objects, including the depth of groundwater, the type of soil in terms of seismicity, the depth of bedrock, three taxa of hydrogeological regions, slopes of the relief. For the selected hydrogeological regions: GR-1 - a horizontal type of drainage is recommended, for GR-2 - vertical or combined types of drainage, for GR-3 - underground drainage is not effective. It is indicated that it is necessary to seismic microzoning not only of the investigated area, but of the entire city of Makhachkala with the prospect of further development.

Engineering-Geological Studies Of The Territory, Soils Of Foundation And Foundations Of The Architectural Monument Of The "Melnikov’s House" In Moscow

2019 ◽  
pp. 41-51
Keyword(s):  
Working Condition ◽  
Overlying Water ◽  
North East ◽  
The North ◽  
Geological Processes ◽  
Architectural Monument ◽  
Geological Conditions ◽  
Zone Of Influence ◽  
Complex Engineering ◽  
Building Engineering

On the basis of engineering and design surveys of the building, engineering-geological and geophysical studies of the soils of the territory conducted by the article authors, as well as with due regard for the results of studies conducted on this territory by other authors, the features of the foundations, soils of their foundation and engineering-geological conditions of the territory of the Melnikov House are established. It is shown that the Melnikov house is located under complex engineering-geological conditions on the territory of high geological risk, in the zone of influence of tectonic disturbance. To the North of the area there is a zone of intersection of the observed disturbance with a larger disturbance that can have an impact on geological processes. To the North-East of the site of the Melnikov House, a sharp immersion of the roof of carbon deposits was revealed. It promotes groundwater seepage into limestone of the carbonate strata from overlying water-bearing sands and activation of processes of suffusion removal and sinkhole phenomena of the soil. The surveyed area is assessed as potentially karst-hazardous and adjacent to it from the North-East territory as karst-dangerous. In this regard any construction on the adjacent territory can provoke activation of sinkhole phenomena on the surface. The foundations of the building are basically in working condition. Existing defects can be eliminated during repair. The foundation soils mainly have sufficient bearing capacity. Areas of the base with bulk soil can be reinforced. However, when developing a project for the reconstruction of the building and its territory, it should be taken into account that the design of the Melnikov House does not provide for its operation on the loads at the formation of sinkholes.

U-Pb on Zircon and Monazite Geochronology of Granites of the Zhytomyr and Sheremetiv Complexes, the North-Western Region of the Ukrainian Shield

2018 ◽  
Vol 40 (2) ◽  
pp. 63-85 ◽  
Author(s):  
L. Shumlyanskyy ◽  
L. Stepanyuk ◽  
S. Claesson ◽  
K. Rudenko ◽  
A. Bekker
Keyword(s):  
Ukrainian Shield ◽  
Western Region ◽  
The North ◽  
North Western
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