رسالة جامعية
Comparative microscopic signatures of microbial and abiotic alterationof calcite ; Signatures microscopiques comparées de l’altération microbienne et abiotique de la calcite
| العنوان: | Comparative microscopic signatures of microbial and abiotic alterationof calcite ; Signatures microscopiques comparées de l’altération microbienne et abiotique de la calcite |
|---|---|
| المؤلفون: | Stigliano, Luca |
| المساهمون: | Institut des Sciences de la Terre (ISTerre), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB Université de Savoie Université de Chambéry )-Centre National de la Recherche Scientifique (CNRS)-Université Gustave Eiffel-Université Grenoble Alpes (UGA), Université Grenoble Alpes 2020-., Damien Daval |
| المصدر: | https://theses.hal.science/tel-04600456Test ; Earth and Planetary Astrophysics [astro-ph.EP]. Université Grenoble Alpes [2020-.], 2024. English. ⟨NNT : 2024GRALU004⟩. |
| بيانات النشر: | HAL CCSD |
| سنة النشر: | 2024 |
| المجموعة: | Institut national des sciences de l'Univers: HAL-INSU |
| مصطلحات موضوعية: | Microtopography, Mineral bioweathering, Biosignatures, Surface roughness, Calcite, Bio-Altération des minéraux, Microtopographie, Rugosité de surface, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] |
| الوصف: | Studying the topography of altered rock surfaces represents a cornerstone for reconstructing past environmental conditions and for the identification of traces of life in the geological record, on Earth and beyond. Indeed, the surface microtopography of altered minerals has proven effective in retaining signatures of fluid-mineral interactions. For example, etch pits are among the commonly accepted signatures of interactions between a highly undersaturated aqueous fluid and a mineral surface. However, additional imprints of water-mineral interactions remain to be defined. On a similar note, weathering imprints supposedly left by microorganisms have been proposed as potential biosignatures. These include etching features and microchannels resembling microbes in ‘size, shape and distribution’. Neverthless, it has been shown that qualitatively similar surface features can also be reproduced through purely abiotic processes. Therefore, it becomes crucial to develop less ambiguous criteria to differentiate between abiotic and biotic weathering features. In this PhD thesis, these questions were addressed through a combination of experimental and modeling approaches. Calcite dissolution experiments were carried out at various saturation states, both under abiotic conditions and with a cyanobacteria biofilm covering the calcite surface. Time-resolved statistical analyses of the resulting surface topography acquired using vertical scanning interferometry were then conducted. The results suggested that the steady-state surface roughness resulting from dissolution can be used as a proxy to back-estimate the saturation state of the fluid. In this context, stochastic modeling of crystal dissolution helped defining the relaxation time that is required for the surface microtopography to switch from a given steady-state configuration to another, as a result of a change in the solution composition. This suggested that the microtopography of naturally weathered minerals may be representative of the fluid composition most recently ... |
| نوع الوثيقة: | doctoral or postdoctoral thesis |
| اللغة: | English |
| العلاقة: | NNT: 2024GRALU004; tel-04600456; https://theses.hal.science/tel-04600456Test; https://theses.hal.science/tel-04600456/documentTest; https://theses.hal.science/tel-04600456/file/STIGLIANO_2024_archivage.pdfTest |
| الإتاحة: | https://theses.hal.science/tel-04600456Test https://theses.hal.science/tel-04600456/documentTest https://theses.hal.science/tel-04600456/file/STIGLIANO_2024_archivage.pdfTest |
| حقوق: | info:eu-repo/semantics/OpenAccess |
| رقم الانضمام: | edsbas.6F5BB34F |
| قاعدة البيانات: | BASE |
| الوصف غير متاح. |