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

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

Mineralogia
Volume 55 (2024): Issue 1 (January 2024)
By: Anna Potysz,  Amr Osman and  Wojciech Bartz  
Open Access
|Dec 2024
Figures & tables

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.

Figure 2.

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).

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.

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.

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.

Figure 7.

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.

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.

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 issue 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.

Volume 55 (2024): Issue 1 (January 2024)
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