scholarly journals The Influence of the Magmatic to Postmagmatic Evolution of the Parent Rock on the Co Deportment in Lateritic Systems: The Example of the Santa Fé Ni-Co Deposit (Brazil)

2021 ◽  
Author(s):  
F. Putzolu ◽  
L. Santoro ◽  
C. Porto ◽  
N. Mondillo ◽  
M. Machado ◽  
...  
Keyword(s):  
Element Distribution ◽  
Parent Rock ◽  
Santa Fe ◽  
Multivariate Statistical ◽  
Central Brazil ◽  
Original Parent ◽  
Components Analysis ◽  
Mineralogical Assemblage ◽  
Ore Zones

Abstract The Santa Fé Ni-Co deposit is a major undeveloped lateritic deposit located in the Goiás State of Central Brazil. The deposit comprises two properties that together have indicated resources of 35.7 million tonnes (Mt), grading 1.14% Ni and 0.083% Co, and inferred resources of 104.3 Mt at 1.03% Ni and 0.054% Co. The laterite was derived from Late Cretaceous alkaline ultramafic lithologies that experienced an initial silicification from Eocene to Oligocene, followed by lateritization and partial reworking in Miocene-Pliocene. The deposit is characterized both by oxide- and phyllosilicate-dominated ore zones. In the former, Ni- and Co-bearing hematite and goethite dominate the supergene mineralogical assemblage, while ore-bearing Mn oxyhydroxides occur as minor components. In the phyllosilicate-dominated horizons the major Ni-carrying phase is chlorite. Multivariate statistical analyses (factor analysis and principal components analysis) conducted on the drill core assay database (bulk-rock chemical analyses) showed that significant differences exist between Ni and Co distributions. The Ni distribution is not controlled by any clear geochemical correlation. This is because the highest Ni concentrations have been measured in the ferruginous and in the ochre saprolite zones, where Ni-bearing minerals (chlorite and goethite) are mostly associated with reworked material and only in a limited way, with zones affected by in situ ferrugination. Cobalt has an atypical statistical distribution at Santa Fé if compared with other laterites, correlated not only with Mn but also with Cr in the majority of the laterite facies. From microchemical analyses on several potential Co-bearing minerals, it was found that the Co-Cr association is related to elevated Co contents in residual spinels, representing unweathered phases of the original parent rock now included in the laterite. This element distribution is atypical for Ni-Co laterite deposits, where Co is normally associated with Mn in supergene oxyhydroxides. In the case of the Santa Fé laterite, the Co concentration in spinels is likely related to magmatic and postmagmatic processes that affected the original parent rock before lateritization, specifically (1) orthomagmatic enrichment of Co in chromite, due to its high affinity to spinels in alkaline melts, and (2) trace elements (i.e., Co, Mn, Ni, and Zn) redistribution during the hydrothermal alteration of chromite into ferritchromite. The Santa Fé deposit represents a good example of how the prelateritic evolution of a parent rock strongly affects the efficiency of Co mobilization and enrichment during supergene alteration. Based on the interpretation of metallurgical test work, a fraction of total Co between 20 and 50% is locked in spinels.

scholarly journals INFLUENCE OF SOIL AND TOPOGRAPHY ON THE COMPOSITION OF A TREE COMMUNITY IN A CENTRAL BRAZILIAN VALLEY FOREST

2005 ◽  
Vol 62 (1-2) ◽  
pp. 69-90 ◽  
Author(s):  
J. R. R. PINTO ◽  
A. T. OLIVEIRA-FILHO ◽  
J. D. V. HAY
Keyword(s):  
Tree Species ◽  
Mato Grosso ◽  
Central Brazil ◽  
Tree Community ◽  
Topographic Survey ◽  
Species Abundances ◽  
Chief Factors ◽  
Components Analysis ◽  
Upper Slope ◽  
Properties Of Soil

The purpose of the present study was to investigate the correlations between environmental variables related to the substrate (soil and topography) and the distribution of tree species in a valley forest in the Chapada dos Guimarães National Park, Mato Grosso State, Brazil. The forest lies in the Cerrado Domain of Central Brazil where the dominant vegetation cover is cerrado (woody savanna). A survey of the tree community registered all live individuals with circumference at breast height (cbh)≥15cm found in eighteen 600m2 plots (total area 1.08ha). The substrate variables used in the gradient analyses were obtained from a topographic survey and from analyses of the chemical and physical properties of soil samples. A principal components analysis of soil and topography variables and a canonical correspondence analysis of the species–environment relationships produced similar results, separating both the substrate variables and the tree species abundances, mainly according to the two types of bedrock, sandstone or slate, underlying their soils, and secondly to the three topographic sectors recognized: Streamside, Mid Slope and Upper Slope. The differences in soil fertility and texture (related to the bedrocks) and the soil water regime (related to both soil texture and topography) were probably the chief factors determining the distribution of tree species in the forest.

Assessing element distribution and speciation in a stream at abandoned Pb–Zn mining site by combining classical, in-situ DGT and modelling approaches

2015 ◽  
Vol 511 ◽  
pp. 423-434 ◽  
Author(s):  
Dario Omanović ◽  
Ivanka Pižeta ◽  
Petra Vukosav ◽  
Elza Kovács ◽  
Stanislav Frančišković-Bilinski ◽  
...  
Keyword(s):  
Element Distribution ◽  
Mining Site ◽  
Modelling Approaches

scholarly journals Principal components analysis of employment in Eastern Europe

2006 ◽  
Vol 53 (4) ◽  
pp. 427-437 ◽  
Author(s):  
Mirko Savic
Keyword(s):  
Eastern Europe ◽  
Principal Components Analysis ◽  
Principal Components ◽  
Statistical Analyses ◽  
Multivariate Methods ◽  
Eastern European ◽  
Multivariate Statistical Analyses ◽  
Multivariate Statistical ◽  
Full Picture ◽  
Components Analysis

For the last decade, the employment structure is one of the fastest changing areas of Eastern Europe. This paper explores the best methodology to compare the employment situations in the countries of this region. Multivariate statistical analyses are very reliable in portraying the full picture of the problem. Principal components analysis is one of the simplest multivariate methods. It can produce very useful information about Eastern European employment in a very easy and understandable way.

Geographic variation in body size of American mink ( Mustela vison ) / Variation géographique de la taille du corps chez le vison d'Amérique ( Mustela vison )

Mammalia ◽  
2006 ◽  
Vol 70 (1-2) ◽  
Author(s):  
Richard T. Stevens ◽  
Michael L. Kennedy
Keyword(s):  
Body Size ◽  
American Mink ◽  
Size Variation ◽  
Mustela Vison ◽  
Morphological Characters ◽  
Geographic Proximity ◽  
Multivariate Statistical ◽  
Components Analysis ◽  
Individual Variables ◽  
Variation Géographique

AbstractSpatial variation in 26 morphological characters of American mink ( Mustela vison ) from 35 localities in North America was investigated using univariate and multivariate statistical analyses. Localities were chosen based on watersheds, and it was hypothesized that high levels of gene flow in minks would prevent partitioning of body size variation within watersheds. All 26 characters in males and 25 of 26 in females exhibited significant interlocality variation. The patterns of variation in body size resulting from principal components analysis indicated that, for both sexes, minks were largest in Alaska, Manitoba, and Alberta; smallest minks were found in Florida and Quebec. There did not appear to be a relationship between body size and geographic proximity. Environmental factors collectively were found to be related to body size, although individual variables were not typically significant. Of 16 environmental variables examined, only longitude was correlated with body size in both sexes, with largest minks in the west and smallest in the east. Latitude was also correlated with body size in females. It was concluded that variation in body size of mink was likely the result of more than one factor that includes both biotic and abiotic features.

Environmental and taxonomic variation in fingernail clam (Bivalvia: Pisidiidae) shell morphology

1983 ◽  
Vol 61 (12) ◽  
pp. 2781-2788 ◽  
Author(s):  
R. C. Bailey ◽  
E. H. Anthony ◽  
G. L. Mackie
Keyword(s):  
Correlation Matrix ◽  
Shell Morphology ◽  
Multivariate Statistical Techniques ◽  
Multivariate Statistical ◽  
Morphometric Variation ◽  
Running Water ◽  
Components Analysis ◽  
Generic Groups ◽  
Fingernail Clams

Variation in the shell morphology of Sphaerium and Musculium fingernail clams was examined using multivariate statistical techniques. On the basis of shell measurements alone, clams from either genera which were collected in running-water habitats could be distinguished, with over 90% accuracy, from clams inhabiting standing water. The discrimination between the two groups was mainly due to the greater size and thickness of shells from clams living in running water. The pisidiid genera Sphaerium and Musculium were also morphologically distinguishable, mainly by size. Morphometric classification of these groups also resulted in over a 90% success rate. The morphometric variation within each of the above groups was further compared using a principal components analysis of each group's morphometric correlation matrix. This analysis revealed differences in growth-related changes in form between the pairs of habitat and generic groups studied. The techniques used to compare ecologically or taxonomically distinct shells appear to be promising for use in either biological monitoring or habitat selection studies.

Dynamic analysis of European organic agricultural areas in the context of sustainable development

2018 ◽  
Vol 47 (1) ◽  
pp. 27-35
Author(s):  
Liliana Duguleană ◽  
Marius Bălăşescu ◽  
Constantin Duguleană ◽  
Simona Bălăşescu ◽  
Nicoleta Andreea Neacşu ◽  
...  
Keyword(s):  
Multivariate Statistical Methods ◽  
Multivariate Statistical ◽  
Eu Member States ◽  
Multiple Regression Method ◽  
Components Analysis ◽  
Main Factors ◽  
Future Economic Development ◽  
Agricultural Areas ◽  
The Eu ◽  
Comparative Manner

The aim of this research was to analyze changes in the size of the European organic agricultural areas between 2000 and 2014 and assess the factors that influenced and differentiated EU member states in this context. The analyses showed the development potential of the EU countries for extension of organic agricultural areas in a comparative manner, based on their future economic development capacities. The article used two multivariate statistical methods, principal components analysis and multiple regression method, to establish and assess the influence of the main factors that contributed to changes in the size of national organic areas. The main factors in 2014 were the European financing for agriculture and rural development, and the migration phenomenon.

Statistical interpretation of medical data of patients with alcohol abuse

Open Medicine ◽  
2012 ◽  
Vol 7 (4) ◽  
pp. 465-474 ◽  
Author(s):  
Ventzislav Bardarov ◽  
Pavlina Simeonova ◽  
Ludmila Neikova ◽  
Krum Bardarov ◽  
Vasil Simeonov ◽  
...  
Keyword(s):  
Alcohol Abuse ◽  
Liver Function ◽  
Ethanol Metabolism ◽  
Statistical Interpretation ◽  
Anthropometric Data ◽  
Multivariate Statistical ◽  
Data Set ◽  
Components Analysis ◽  
Significant Patterns

AbstractAn attempt is made to assess a set of biochemical, kinetic and anthropometric data for patients suffering from alcohol abuse (alcoholics) and healthy patients (non-alcoholics). The main goal is to identify the data set structure, finding groups of similarity among the clinical parameters or among the patients. Multivariate statistical methods (cluster analysis and principal components analysis) were used to assess the data collection. Several significant patterns of related parameters were found to be representative of the role of the liver function, kinetic and anthropometric indicators (conditionally named “liver function factor”, “ethanol metabolism factor”, “body weight factor”, and “acetaldehyde metabolic factor”). An effort is made to connect the role of kinetic parameters for acetaldehyde metabolism with biochemical, ethanol kinetic and anthropometric data in parallel.

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