scholarly journals Application of Morphostructural and Spatial Analyses in Placer-Gold Source Interpretation within Wonaka Schist Belt, Northwestern-Nigeria

2021 ◽  
Vol 28 (2) ◽  
pp. 43-54
Author(s):  
H.M. Grema ◽  
W.T. Andongma
Keyword(s):  
Energy Dispersive Spectrometry ◽  
Drainage Basin ◽  
Secondary Growth ◽  
Field Studies ◽  
Schist Belt ◽  
Spatial Analyses ◽  
Placer Gold ◽  
Fluvial Transport ◽  
Placer Deposits ◽  
Physical Features

Morphologic and placer features were used to characterize, determine the provenance, and transport distances of gold grains within the River Gagare drainage basin of the Wonaka Schist Belt. Field studies, scanning electron examination coupled with energy dispersive spectrometry and binocular microscopy were utilized to study the spatial distributions, shape, size, inclusions, primary and fluvial transport-induced deformations, as well as Cailleux flatness indices. The grains are dominantly subrounded (71%), with the length between 35 – 800 µm and width of 10 – 778 µm while the rounded grains have a mean length of 292.5 µm and width of 179 µm. Similar values for circularity and sphericity are observed in the sub-rounded grains, with slight variations of 2.7 circularity and 2.6 sphericitydistinguished in the rounded grain subset. The Cailleux flatness index range from 2.5 to 9 for subrounded grains and 2 – 15.5 for the rounded, indicating the multisource nature of the grains. The grains are consistent with short to moderate transport distances from the lode sources. The similarities in physical features, lack of delicate secondary growth structures and irregular grain outlines point to a detrital source for the placer deposits. Evidence of emulsion crystallisation type is indicated by the presence of sub- to anhedral  inclusions within the Au grains. Keywords: Placer gold, Cailleux flatness indices, Wonaka Schist Belt, Provenance, Northwest Nigeria

scholarly journals The Stages of the Cultural Landscape Transformation of Seaside Resorts in Poland against the Background of the Evolving Nature of Tourism

Land ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 55 ◽  
Author(s):  
Wojciech Bal ◽  
Magdalena Czalczynska-Podolska
Keyword(s):  
Urban Planning ◽  
Cultural Landscape ◽  
Field Studies ◽  
Spatial Analyses ◽  
Historical Interpretation ◽  
Landscape Transformation ◽  
Characteristic Features ◽  
Communist Countries ◽  
Tourism Services ◽  
Interpretation Studies

The development of tourism determines the cultural landscape transformation, spatial development of coastal localities, scale of recreational architecture and other forms of development related to tourism services. The article presents research aiming to analyze tourism development in the context of its impact on the cultural landscape of Polish coastal localities, taking into account the specificity of post-communist countries and supra-regional tendencies. The main objective of this study was to analyze the development of tourism in the context of its impact on the cultural landscape seaside towns and to identify, on the basis of the changes, the nature of tourism and forms of recreation in particular stages of the shaping of elements in coastal locality spaces and recreational architecture. The research was based on historical-interpretation studies, field studies of selected coastal localities, including urban-planning inventories, landscape, and functional and spatial analyses. The research carried out resulted in the identification of the stages of the cultural landscape transformation of coastal localities and indication of characteristic features of architecture and landscape. The journey along the coastline is a temporal journey through the changing nature of buildings, allowing observation of the stage-by-stage nature of investment processes in response to the changing needs of tourists.

scholarly journals Housing Vulnerability and Property Prices: Spatial Analyses in the Turin Real Estate Market

2018 ◽  
Vol 10 (9) ◽  
pp. 3068 ◽  
Author(s):  
Alice Barreca ◽  
Rocco Curto ◽  
Diana Rolando
Keyword(s):  
Real Estate ◽  
Social Vulnerability ◽  
Real Estate Market ◽  
Spatial Analyses ◽  
Price Determination ◽  
Spatially Correlated ◽  
Property Prices ◽  
Vulnerability Indicators ◽  
Property Price ◽  
Physical Features

In the literature, several vulnerability/resilience indicators and indexes are based and assessed by taking into account and combining different dimensions. Housing vulnerability is one of these dimensions and is strictly related to the buildings’ physical features and to the socio-economic condition of their occupants. This research aims to study housing vulnerability in relation to the real estate market by identifying possible indicators and spatially analyzing their influence on property prices. Assuming the city of Turin and its territorial segmentation as a case study, spatial analyses were performed to take into account the presence of spatial dependence and to identify the variables that significantly influence the process of property price determination. The results of this study highlighted the fact that two housing vulnerability indicators, representative of fragile buildings’ physical features, were spatially correlated with property prices and had a significant and negative influence on them. In addition, their comparison with two social vulnerability indicators demonstrated that the presence of economical buildings and council houses was spatially correlated with the presence of people with a low education level. The results of the spatial regression model also confirmed that one of the social vulnerability indicators had the highest and most negative explanatory power in the property price determination process.

Quantitative texture analysis of alluvial gold: primary and secondary signatures

2021 ◽  
Author(s):  
Juan Gómez-Barreiro ◽  
Santos Barrios-Sánchez ◽  
José Manuel Compaña Prieto ◽  
Juan Morales Sánchez-Migallón ◽  
Kelvin dos Santos Alves ◽  
...  
Keyword(s):  
Rietveld Method ◽  
Secondary Growth ◽  
Primary Source ◽  
Close Correlation ◽  
Gold Deposits ◽  
Pure Gold ◽  
Transport Length ◽  
Alluvial Gold ◽  
Placer Deposits ◽  
Non Destructive

<p>The origin of gold nuggets (Au‐Ag alloys) is not completely understood. They crop out in placer deposits, potentially derived from a primary source (hydrothermal/magmatic). Meteorization, erosion and transport of primary gold deposits result in the liberation of a variety of particle size. Recent investigations suggest that both primary and secondary microstructural features may be preserved and could be related to deformation during transport, recrystallization and primary formation. Besides, the contribution of biological mechanisms (biomineralization) may have played an important role during secondary growth in some nuggets. In many cases, there is no clear evidence to distinguish between supergenic and hypogenic gold, so texture information could be excellent information to constrain the origin. Besides, it has been demonstrated that crystallography controls the de‐alloying processes in gold nuggets. This mechanism, that transforms the primary Au–Ag alloys into pure gold by preferential dissolution of Ag along crystal boundaries, could be determined by variations on texture, a factor never explored before, which may explain the dispersion in de‐alloying values in the same deposit.</p><p> </p><p>In this case we have explored a selection of gold nuggets collected in the W sector of the Iberian Massif (Spain), representing the principal morphological types. As a non-destructive technique neutron diffraction appears as the technique of choice in this case. Beside, neutrons absorption is very low so that large samples could be investigated. Samples were analyzed in transmission at ILL (Grenoble) for texture. Quantitative texture and gold crystallinity was calculated using Rietveld method as implemented in Maud software (EWIMV). Mono- and polycrystalline nuggets and alloy composition were clearly identified in each particle with this technique. Our results show a close correlation between the morphology (i.e. transport length) of the particle and the crystallographic results, particularly for fibrous and discoid shapes (i.e. Zingg, Corey shape factor), what could be used to develop better transport models (distance-to-bedrock sources) and understand multisource gold placer assemblages. </p>

Sources of some heavy minerals and their association with gold-bearing stream sediments in the Gagare Drainage Basin, Wonaka Schist belt northwestern Nigeria

2021 ◽  
Vol 13 (1) ◽  
pp. 68-79
Author(s):  
H.M. Grema ◽  
H.A. Ibrahim ◽  
M. Abdulkarim ◽  
M. Lawal ◽  
K. Mbitsa ◽  
...  
Keyword(s):  
Drainage Basin ◽  
Stream Sediments ◽  
Heavy Minerals ◽  
Schist Belt ◽  
Gold Bearing

No Abstract.

scholarly journals Current state, prospects and problems of the gold mining industry of the Trans-Baikal Territory

2022 ◽  
Vol 962 (1) ◽  
pp. 012023
Author(s):  
M A Latysheva
Keyword(s):  
Gold Mining ◽  
Negative Impact ◽  
Mining Industry ◽  
Precious Metals ◽  
Environmental Damage ◽  
Production Volume ◽  
Total Production ◽  
Placer Gold ◽  
Current State ◽  
Placer Deposits

Abstract The article considers the current state, problems and prospects of gold mining in the Trans-Baikal Territory. There has been an increase in the volume of gold production from ore and placer deposits over the past 5 years. Placer deposits make up a significant part of the total production volume. The reduction of reserves in placers and the decrease in the quality of minerals in them open up new prospects for the extraction of precious metals, namely in ore gold mining. The extraction of placer gold, even with the best existing technologies, remains a sector of high environmental risk, in many settlements there is a gradual decline in the population and the “extinction” of settlements, as well as illegal gold mining is gaining momentum. Neither regional nor federal environmental supervision bodies have the opportunity to resist the destruction and degradation of nature from the extraction of placer gold. In general, this leads to an increase in the negative impact of placer gold mining on natural complexes and socio-economic sustainable development of regions and municipalities on the territory of which this type of activity is carried out, an increase in accumulated environmental damage.

scholarly journals Secondary Melt Ornamentation on Westwater, Utah Microspherules: Evidence of an Extraterrestrial Provenance

2003 ◽  
Vol 11 (1) ◽  
pp. 37-37
Author(s):  
J. W. Fandrich ◽  
Richard C. Dujay
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Energy Dispersive Spectrometry ◽  
Energy Dispersive ◽  
Physical Features ◽  
Scanning Electron

Microspherules (MS) ranging in size from 50μm to 425μm were discovered at Westwater, Utah in 1999. Examination of these particles using a scanning electron microscope identifies certain physical features that support an extraterrestrial (ET) provenance for these objects. Energy dispersive spectrometry (EDS) was used to determine the qualitative chemistry of these particles.

scholarly journals Assessment of environmental water requirement for rivers of the Miankaleh wetland drainage basin

2020 ◽  
Vol 10 (11) ◽  
Author(s):  
V. Gholami ◽  
A. Khalili ◽  
H. Sahour ◽  
M. R. Khaleghi ◽  
E. Nikzad Tehrani
Keyword(s):  
Drainage Basin ◽  
Field Studies ◽  
Environmental Water ◽  
Water Requirement ◽  
Physical Habitat ◽  
Wetland Drainage ◽  
The North ◽  
Habitat Simulation ◽  
North Of Iran ◽  
Wetted Perimeter

Abstract The Miankaleh wetland, one of the richest ecosystems in the north of Iran, has experienced an unprecedented environmental degradation caused by overexploitation of the water resources and climatic changes in recent years. This research aims to estimate the environmental water requirement (EWR) for the rivers that drain into the wetland. For this purpose, comprehensive data were collected through physiographic, climatic, hydrologic, ecologic, and field studies of the wetland and its drainage basin. To estimate the EWR, we applied several methods including the Tenant, the Eco-deficit, the flow duration curve, the Wetted-Perimeter method, and the physical habitat simulation model (PHABSIM) and the results were evaluated based on the natural discharge of the rivers before retrogression of the Miankaleh wetland. Further, the results showed that the consideration should be given to the Wetted-Perimeter and the PHABSIM Model for estimation of the EWR for the rivers of the Miankaleh wetland given the seasonality of the rivers and hydroclimatic condition of the study area. The mean annual EWR of the rivers was estimated between 0.12 and 2.03 m3/s, which is close to the values of the bank full flows. The current discharge of the rivers are less than the estimated EWR, showing the discharge rates do not meet the water requirement for aquatic species of the Miankaleh wetland

scholarly journals Geostatistical analysis of space variation in underground water various quality parameters in Kłodzko water intake area (SW part of Poland)

2016 ◽  
Vol 38 (3) ◽  
pp. 15-34
Author(s):  
Barbara Namysłowska-Wilczyńska
Keyword(s):  
Water Quality ◽  
Spatial Variation ◽  
Water Intake ◽  
Drainage Basin ◽  
Underground Water ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Ammonium Ion ◽  
Spatial Analyses ◽  
Block Kriging

Abstract This paper presents selected results of research connected with the development of a (3D) geostatistical hydrogeochemical model of the Kłodzko Drainage Basin, dedicated to the spatial variation in the different quality parameters of underground water in the water intake area (SW part of Poland). The research covers the period 2011-2012. Spatial analyses of the variation in various quality parameters, i.e., contents of: iron, manganese, ammonium ion, nitrate ion, phosphate ion, total organic carbon, pH redox potential and temperature, were carried out on the basis of the chemical determinations of the quality parameters of underground water samples taken from the wells in the water intake area. Spatial variation in the parameters was analyzed on the basis of data obtained (November 2011) from tests of water taken from 14 existing wells with a depth ranging from 9.5 to 38.0 m b.g.l. The latest data (January 2012) were obtained (gained) from 3 new piezometers, made in other locations in the relevant area. A depth of these piezometers amounts to 9-10 m. Data derived from 14 wells (2011) and 14 wells + 3 piezometers (2012) were subjected to spatial analyses using geostatistical methods. The evaluation of basic statistics of the quality parameters, including their histograms of distributions, scatter diagrams and correlation coefficient values r were presented. The directional semivariogram function γ(h) and the ordinary (block) kriging procedure were used to build the 3D geostatistical model. The geostatistical parameters of the theoretical models of directional semivariograms of the water quality parameters under study, calculated along the wells depth (taking into account the terrain elevation), were used in the ordinary (block) kriging estimation. The obtained results of estimation, i.e., block diagrams allowed us to determine the levels of increased values of estimated averages Z* of underground water quality parameters.

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