List of Articles

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  1 - Employing different techniques to explore, modeling and reserve estimation of gypsum deposit in the northwest of Tafresh district, Markazi province
  Reza Ahmadi
  <p>In the present research, to explore gypsum reserves in the northwest of Tafresh district, a complete process including prospecting to reserve estimation has been carried out. To achieve the goal, first, an extensive area of 4500 km2 was investigated using remote sens More

  <p>In the present research, to explore gypsum reserves in the northwest of Tafresh district, a complete process including prospecting to reserve estimation has been carried out. To achieve the goal, first, an extensive area of 4500 km2 was investigated using remote sensing operation through Landsat 8 Operational Land Imager (OLI) images. Using proper pre-processing and processing techniques containing principal component analysis, false color band combination, least squares regression and spectral angle mapper on the images, 17 promising areas scattered in the region were identified. Based on more detailed studies and field surveys of the promising areas, it was specially focused on Darbar gypsum deposit located nearby Darbar village. Therefore, a variety of exploratory activities comprising six trenches with a total volume of 135.61 m3, one stope (selective mining unit), 1:1000 topographic-geological map, chemical analysis of 9 samples and drilling of one exploratory borehole with a depth of about 40 m was performed. The results of the chemical analysis of the samples show that the total percentage of SO3 and CaO compounds for all tested samples is more than 76%. In addition, the result of the technological test to determine the quality characteristics of the stone and baking ability in the pilot scale evaluated by Nizar Cement Factory of Qom is desirable. Gypsum modeling and reserve estimation of this deposit were also done with the classical method of contour lines using Surfer software. Based on the calculations, the in-place reserve of Darbar gypsum deposit was estimated significant amount of 5982610 tons.</p> Manuscript profile
• Open Access Article
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  2 - Spurious Correlation and the Closure Property of Compositional Data in Geological Sciences
  Hamid Ghorbani
  <p>In earth sciences, measurements usually produce compositional data with a property called closedness. Researchers who use common statistical methods on compositional data ignore spurious correlations, which causes incorrect results. This article introduces transforma More

  <p>In earth sciences, measurements usually produce compositional data with a property called closedness. Researchers who use common statistical methods on compositional data ignore spurious correlations, which causes incorrect results. This article introduces transformations for opening closed system of compositional data. These transformations include the additive logarithmic ratio (alr), the centred logarithmic ratio (clr), and the isometric logarithmic ratio (ilr). They are all defined in terms of logarithms of ratios. We then applied the clr transformation to a soil chemical data set. We also analysed the results of applying cluster analysis on the clr transformed data using Spearman's correlation coefficient matrix as distance. We also investigated how applying clr transformation affects spurious correlation, skewness and outliers in the data using R statistical software.</p> Manuscript profile