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Bioweathering of Egyptian Nubian sandstone and Theban limestone: three months insight by experimental incubation

Mineralogia
Volume 55 (2024): Issue 1 (January 2024)
By:
Open Access
|Dec 2024

Figures & Tables

Figure 1.

A map showing the locations of sampling sites, where Nubian sandstone S1-S6 (A) and Theban limestone (B) have been collected.
A map showing the locations of sampling sites, where Nubian sandstone S1-S6 (A) and Theban limestone (B) have been collected.

Figure 2.

Flowchart presenting experimental approach undertaken to decipher stone weathering.
Flowchart presenting experimental approach undertaken to decipher stone weathering.

Figure 3.

Microphotographs of Nubian sandstone (S3, S6) taken in plane-polarized (left column) and cross-polarized light (right column).
Microphotographs of Nubian sandstone (S3, S6) taken in plane-polarized (left column) and cross-polarized light (right column).

Figure 4.

Results of X-ray diffraction and thermal analysis of Theban limestone (TL) and Nubian sandstone (S3, S6). Mineral abbreviations: cal-calcite, qz-quartz, kln-kaolinite, hl-halite, afs-alkali feldspar, zrn-zircon, gth-goethite, hem-hematite, mag-magnetite, gp-gypsum, lpc-lepidocrocite (Warr, 2021); dh-dehydration, dxo-dehydroxylation.
Results of X-ray diffraction and thermal analysis of Theban limestone (TL) and Nubian sandstone (S3, S6). Mineral abbreviations: cal-calcite, qz-quartz, kln-kaolinite, hl-halite, afs-alkali feldspar, zrn-zircon, gth-goethite, hem-hematite, mag-magnetite, gp-gypsum, lpc-lepidocrocite (Warr, 2021); dh-dehydration, dxo-dehydroxylation.

Figure 5.

BSE images and EDS spectra of Nubian sandstone (S3, S6) and Theban limestone (TL) before leaching experiment. 1 – euhedral dolomite; 2 – bioclast; 3 – Fe-bearing phases encrusting bioclast; 4, 9 – alkali feldspar; 5 – quartz; 6, 10 – Fe-bearing phases in matrix; 7, 11 – kaolinite; 8 – magnetite.
BSE images and EDS spectra of Nubian sandstone (S3, S6) and Theban limestone (TL) before leaching experiment. 1 – euhedral dolomite; 2 – bioclast; 3 – Fe-bearing phases encrusting bioclast; 4, 9 – alkali feldspar; 5 – quartz; 6, 10 – Fe-bearing phases in matrix; 7, 11 – kaolinite; 8 – magnetite.

Figure 6.

BSE images and EDS spectra of Nubian sandstone (S3, S6) and Theban limestone (TL) after leaching experiment. 1 – bioclast; 2 – bioclast covered with biofilm, 3 – euhedral dolomite; 4 – quartz and biofilm; 5 – syntaxial quartz overgrowths; 6 – bacteria on kaolinite aggregate; 7 – kaolinite aggregate; 8 – magnetite; 9, 11 – Fe-bearing phases; 10 – single kaolinite flake.
BSE images and EDS spectra of Nubian sandstone (S3, S6) and Theban limestone (TL) after leaching experiment. 1 – bioclast; 2 – bioclast covered with biofilm, 3 – euhedral dolomite; 4 – quartz and biofilm; 5 – syntaxial quartz overgrowths; 6 – bacteria on kaolinite aggregate; 7 – kaolinite aggregate; 8 – magnetite; 9, 11 – Fe-bearing phases; 10 – single kaolinite flake.

Figure 7.

Microphotographs of Theban limestone (TL) taken in plane-polarized (left column) and cross-polarized light (right column).
Microphotographs of Theban limestone (TL) taken in plane-polarized (left column) and cross-polarized light (right column).

Figure 8.

Evolution of elements leaching from studied sandstones throughout the experiment (BAC: growth medium with bacteria filtered at <0.22 μm; MED: sterile growth medium; H2O: sterile water). Error bars present standard deviation of the replicate values.
Evolution of elements leaching from studied sandstones throughout the experiment (BAC: growth medium with bacteria filtered at <0.22 μm; MED: sterile growth medium; H2O: sterile water). Error bars present standard deviation of the replicate values.

Figure 9.

Evolution of elements leaching from studied limestone throughout the experiment (BAC: growth medium with bacteria filtered at <0.22 μm; MED: sterile growth medium; H2O: sterile water). Error bars present standard deviation of the replicate values.
Evolution of elements leaching from studied limestone throughout the experiment (BAC: growth medium with bacteria filtered at <0.22 μm; MED: sterile growth medium; H2O: sterile water). Error bars present standard deviation of the replicate values.

Specific conditions set in the incubation experiments_

IncubationNameCharacteristics of the constituentsPresence of bacteriaInitial pHFinal pH S3Final pH S6Final pH TLSiderophore concentrationProxy
Ultrapure waterWATnone-5.68.78.68.1-Neutral unaggressive conditions
Growth mediumMEDInorganic, organic (succinic acid)-7.07.87.88.0-Chemical weathering
Growth medium with bacteria Pseudomonas fluorescensBACInorganic, organic (succinic acid, microbially-derived compounds including siderophore)+7.08.79.19.2S3: 45.2 μM L−1S6: 75.5 μM L−1TL: 90.6 μM L−1Biotic weathering

Chemical composition of the studied samples_

[Wt. %]Sandstone S3Sandstone S6Limestone TL
SiO292.5785.677.08
Al2O33.120.960.54
Fe2O31.187.940.33
MgO0.070.110.51
CaO0.071.5650.22
Na2O0.070.130.15
K2O0.870.190.08
TiO20.840.180.03
LOI1.03.140.7
DOI: https://doi.org/10.2478/mipo-2024-0006 | Journal eISSN: 1899-8526 | Journal ISSN: 1899-8291
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Language: English
Page range: 60 - 79
Submitted on: Jul 4, 2024
Accepted on: Nov 7, 2024
Published on: Dec 13, 2024
Published by: Mineralogical Society of Poland
In partnership with: Paradigm Publishing Services
Publication frequency: 1 times per year
Keywords:
stone,
minerals,
dissolution,
leaching,
bacteria
Related subjects:
Geosciences,
Geophysics,
Geosciences, other

© 2024 Anna Potysz, Amr Osman, Wojciech Bartz, published by Mineralogical Society of Poland
This work is licensed under the Creative Commons Attribution 4.0 License.

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