An evaluation of the relationship between physical

Authors: Erdem Emin Maras Mustafa Caniberk Mehmet Serhat Odabas Burcu Degerli Süleyman Sirri Maras Hadi Hakan Maras

Publish Date: 2016/02/24

Volume: 9, Issue: 2, Pages: 164-

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Abstract

We investigated the relationships between mineral content and the physical and mechanical properties of landscape rock using a nondestructive remote sensing method applied in the laboratory Using this technique the spectral properties of the landscape rock could be collected at different wavelengths without harming the samples Differences in spectral reflectance were compared with the physical and mechanical properties of the stone Significant correlations were observed between reflectance values and the rocks’ mechanical and physical properties with correlation coefficients of 95 to 99  However establishing a correlation between two variables is not a sufficient condition to establish a causal relationship Mineral densities and mineral content are characteristics used for the classification of landscape rock We have concluded that although spectral signatures from landscape rock can be used for predicting which stones might have similar features when comparing two batches of stone the high correlations we discovered cannot confirm a cause and effect relationship that would allow for the prediction of a rock’s physical and mechanical properties Although this conclusion is disappointing the mineral content and the significant correlations discovered by hyperspectral reflectance scanning can be used as supplementary information when comparing two samples of landscape rockMany Al–OH containing minerals have subtle compositional variations that are indicative of the chemistry of fluids present at the time of the alteration event Since these compositional variations result in wavelength shifts of the Al–OH absorption feature near 2200 nm the wavelength position of this feature is an indicator of geochemical conditions at the time of the alteration eventThe phyllosilicate kaolinite is produced by both weathering and alteration events The crystallinity of the resulting kaolinite is strongly influenced by the temperature of the fluids at the time of formation Since kaolinite crystallinity influences the shape of the Al–OH absorption feature centered near 2200 nm a measurement of this feature shape is indicative of the temperature of formation Kx scalar values greater than 1 are indicative of a weatheringproduced kaolinite while values less than 1 are generally associated with those produced by higher temperature alteration events the lower the Kx value the higher the temperature of formationThe phyllosilicates in the illitemuscovite group are produced over a broad range of geochemical conditions With increasing metamorphic grade the reflectance spectrum of these minerals indicate a loss of molecular water as inferred from the depth of the H2O absorption feature near 1950 nm along with an increase in crystallinity as inferred from the depth of the Al–OH absorption feature near 2200 nm ISM scalar values greater than 1 are indicative of a low metamorphic grade illite while values less than 1 are generally associated with those produced by higher temperature alteration events the lower the ISM value the higher the alteration temperature can be observedThe chlorite group minerals are produced over a broad range of geochemical conditions With increasing metamorphic grade the reflectance spectrum of these minerals indicate a loss of molecular water as inferred from the depth of the H2O absorption feature near 1950 nm along with an increase in crystallinity as inferred from the depths of the Mg–OH near 2350 nm and Fe–OH near 2260 nm absorption featuresMany Mg–OHcontaining minerals have subtle compositional variations that are indicative of the chemistry of fluids present at the time of the alteration event Since these compositional variations result in wavelength shifts of the Mg–OH absorption feature near 2350 nm the wavelength position of this feature is an indicator of geochemical conditions at the time of the alteration eventMany Fe–OHcontaining minerals have subtle compositional variations that are indicative of the chemistry of fluids present at the time of the alteration event Since these compositional variations result in wavelength shifts of the Fe–OH absorption feature near 2260 nm the wavelength position of this feature is an indicator of geochemical conditions at the time of the alteration eventIron oxides and oxyhydroxides are produced under a wide range of geologic conditions All the Fe3+ minerals the most common of which are hematite and goethite have a similar feature in the 750–1000nm region The position of this feature shifts depending on the identity of the Fe3+ mineralIron oxides and oxyhydroxides are produced under a wide range of geologic conditions All the Fe3+ minerals the most common of which are hematite and goethite have strong absorption short of about 550 nm The intensity of this feature depends strongly on the abundance of Fe3+ minerals The Fe3i scalar tracks the intensity of this feature the higher the Fe3i value the more intense the Fe3+ absorptionThe relative depths of the Al–OH Fe–OH and Mg–OH features centered in the 2160 to 2370nm wavelength range and seen in the reflectance spectrum of an alteration produced mineral assemblages can provide an indication of geochemical conditions The Al–Fe–Mg scalar reports the wavelength of the deepest absorption feature of these three

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