Study of Limestones from the Nfayil Formation in Bahr Al-Najaf Depression and Suitability for Thermal conductivity

Ahmed, Hussien Ghni; Issa, Murtadha Jabbar; Ali, Jaffar Hussain

doi:10.24996/ijs.2022.63.7.21

Cited by 2 publications

(2 citation statements)

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“…On one hand, dissolved salts and freeze-thawing degrade the rock's fabric; on the other hand, the carbonate matrix slowly dissolves through weathering, which leads to increased porosity and ultimately decreased petrophysical properties. Nevertheless, most limestone and dolostone types have proven to be durable materials for construction purposes (Ahmed et al 2021;Balogh 1994;Knauer 1994). In instances where the mentioned freshwater carbonate rocks are used for construction in Hungary, the major cause of carbonate rock weathering is the absorption of groundwater and infiltration of rainwater, leading to both chemical weathering, such as carbonate dissolution and physical weathering due to freeze-thaw processes (Ruedrich et al 2011, Claes et al 2016.…”

Section: Introductionmentioning

confidence: 99%

The use of CT analysis in revealing structural heterogeneity of freshwater carbonate decoration and construction stones

Alzoubi,

Gulyás,

Geiger

2023

Archeometriai Műhely

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This article presents the findings of a CT analysis conducted on freshwater carbonate rocks found in the Danube-Tisza Interfluve. These rocks are utilized for both construction and decoration purposes in the medieval buildings of the region. The aim of the study was to uncover some petrophysical properties of the rocks deriving from the Csólyospálos quarry. The proportions of the main constituents of the rocks carry significant information about the formation and alteration history of sedimentary rocks. To comprehend and assess the nature of these processes, as well as the resulting spatial variations, it is necessary to gather quantitative data on the distribution of these constituents at both macro- and microscales. The researchers employed an EMmixture analysis that considered the density differences among the individual constituents to determine the quantitative characteristics of the main components that form the rocks. By setting a threshold value to distinguish macropores (empty spaces) with lower density values from the solid matrix, the percentage of voids was calculated for each CT slice. The distribution of these voids was examined in three dimensions along all possible axial directions (X, Y, Z). Watershed algorithm, and Laplace operator were applying on selected CT slices that corresponded to areas with similar compositional features. This approach helped identify potential flow directions within the rocks. The spatial distribution and orientation of macropores, which could be visualized using CT at a resolution of over 200 microns, provided valuable insights into the paths through which water could enter the carbonate rocks used for construction or decoration. This information is crucial in understanding structural damage caused by frost weathering and dissolution via capillary action once a staticstate flow is established. Furthermore, these findings complement the results obtained from laboratory geotechnical measurements.

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Section: Introductionmentioning

confidence: 99%

The use of CT analysis in revealing structural heterogeneity of freshwater carbonate decoration and construction stones

Alzoubi,

Gulyás,

Geiger

2023

Archeometriai Műhely

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“…This is because the mineral matrix slowly dissolves through weathering, which leads to increased porosity and ultimately decreased petrophysical properties. Nevertheless, most limestone and dolostone types have proven to be durable materials for construction purposes (Ahmed et al 2021;Balogh 1994;Knauer 1994). In instances where the mentioned freshwater carbonate rocks are used for construction in Hungary, the major cause of carbonate rock weathering is the absorption of groundwater and infiltration of rainwater, leading to both chemical weathering in freshwater carbonate dissolution and physical weathering due to freeze/thaw processes (Ruedrich et al 2011, Claes et al 2016.…”

Section: Kivonatmentioning

confidence: 99%

Characterizing Small-Scale Heterogeneity in Quaternary Freshwater Carbonates of Hungary Using CT Scan Data

Alzoubi

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Carbonate rocks are among the sedimentary systems which preserve information on the formation and diagenetic history expressed in its composition (distribution of its major rockforming components (RFC). For estimating RFC proportions at the micro-scale, a simple counting of visible RFCs in thin sections using overlaid grids is a long-used, well-established technique. However, computer tomography (CT) analysis provides us with quantitative data in 3D at both the scale of the entire sample and a resolution defined by dimensions of the voxels at the micro-scale. The quantitative data expressed in Hounsfield units (HU) correlates with the density of RFCs. In this work statistical properties of CT-based data for selected freshwater carbonate samples from the Danube-Tisza Interfluve have been assessed using histograms and boxplots. Univariate statistical parameters characterize each sample. The maximum-likelihood method of mixture analysis has been adapted to recover and estimate the parameters of these subpopulations. Subpopulations have been defined in the form of overlapping intervals using statistical parameters gained (mean±2STD). Five major components have been defined: empty and partially or entirely filled pores by calcite, limestone micrite, dolomite micrite matrix and limonite saturated matrix.

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Study of Limestones from the Nfayil Formation in Bahr Al-Najaf Depression and Suitability for Thermal conductivity

Cited by 2 publications

References 1 publication

The use of CT analysis in revealing structural heterogeneity of freshwater carbonate decoration and construction stones

The use of CT analysis in revealing structural heterogeneity of freshwater carbonate decoration and construction stones

Characterizing Small-Scale Heterogeneity in Quaternary Freshwater Carbonates of Hungary Using CT Scan Data

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