Effect of Mineral Processes and Deformation on the Petrophysical Properties of Soft Rocks during Active Faulting
| Autor: | Isabel Abad, Anita Torabi, Francisco J. García-Tortosa, Tor Saltnes Skram Ellingsen, Juan Jiménez-Millán, Rosario Jiménez-Espinosa |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
lcsh:QE351-399.2
deformation bands 010504 meteorology & atmospheric sciences aragonite and dolomite microsealing Dolomite Geochemistry Cataclastic rock engineering.material Fault (geology) 010502 geochemistry & geophysics 01 natural sciences chemistry.chemical_compound clay-filling stylolites 0105 earth and related environmental sciences Calcite geography lcsh:Mineralogy geography.geographical_feature_category Aragonite Geology Geotechnical Engineering and Engineering Geology chemistry Deformation mechanism fracture Stylolite engineering active faulting Deformation bands permeability human activities |
| Zdroj: | Minerals Volume 10 Issue 5 Minerals, Vol 10, Iss 444, p 444 (2020) |
| ISSN: | 2075-163X |
| Popis: | We have studied damage zones of two active faults, Baza and Padul faults in Guadix-Baza and Granada basins, respectively, in South Spain. Mineral and microstructural characterization by X-ray diffraction and field emission electron microscopy studies have been combined with structural fieldwork and in situ measurements of rock properties (permeability and Young&rsquo s modulus) to find out the relation between deformation behavior, mineral processes, and changes in the soft rock and sediment properties produced by fluid flow during seismic cycles. Our results show that microsealing produced by precipitation of dolomite and aragonite along fractures in the damage zone of Baza Fault reduces the permeability and increases the Young&rsquo s modulus. In addition, deformation bands formed in sediments richer in detrital silicates involved cataclasis as deformation mechanism, which hamper permeability of the sediments. In the Granada Basin, the calcarenitic rocks rich in calcite and clays in the damage zone of faults associated to the Padul Fault are characterized by the presence of stylolites without any carbonate cement. On the other hand, marly lithofacies affected by faults are characterized by the presence of disaggregation bands that involve cracking and granular flow, as well as clay smear. The presence of stylolites and deformation bands in these rocks reduces permeability. |
| Databáze: | OpenAIRE |
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