Skip to main content

Research Repository

Advanced Search

A micromechanical investigation of diagenetically-induced changes to the anisotropic elastic properties of calcareous mudstones

Graham, Samuel P.; Aplin, Andrew C.; Rouainia, Mohamed; Ireland, Mark T.; Armitage, Peter J.

A micromechanical investigation of diagenetically-induced changes to the anisotropic elastic properties of calcareous mudstones Thumbnail


Authors

Samuel P. Graham

Mohamed Rouainia

Mark T. Ireland

Peter J. Armitage



Abstract

Microscale diagenetic changes that occur during burial exert a profound influence on the elastic and mechanical properties of sediments—but are poorly quantified. The focus here is on how diagenesis influences the elastic properties of carbonate-rich mudstones, which are subject to a wide range of physical and chemical changes. Nanoindentation data for gas-window (180 C) Eagle Ford formation samples give intrinsic indentation moduli of the clay-sized calcite matrix of 40–50 GPa, which contrasts with 60–77 GPa for diagenetic calcite fills of foraminifera tests, closer to values for highly crystalline calcite. The matrix calcite is weakly anisotropic. Inverse analysis of immature (< 70 C) organic-rich chalks gives much lower intrinsic indentation moduli for biogenic calcite, between 17 and 30 GPa; the calcite is also more anisotropic, with values of 1.3. Diagenesis, which includes recrystallisation and pore-filling cementation, results in calcite becoming elastically stiffer and behaving in an increasingly isotropic manner, in agreement with grain scale studies using atomic force microscopy. The results demonstrate that nanoindentation can resolve diagenetic contributions to the mechanical response of mudstones, and suggest intrinsic structural changes to calcite, in addition to diagenetic cementation, need to be accounted for in rock-physics models of mud-rich sediments.

Citation

Graham, S. P., Aplin, A. C., Rouainia, M., Ireland, M. T., & Armitage, P. J. (2023). A micromechanical investigation of diagenetically-induced changes to the anisotropic elastic properties of calcareous mudstones. Geomechanics and Geophysics for Geo-Energy and Geo-Resources, 9(1), Article 107. https://doi.org/10.1007/s40948-023-00634-z

Journal Article Type Article
Acceptance Date Jun 27, 2023
Online Publication Date Aug 26, 2023
Publication Date 2023-12
Deposit Date Oct 18, 2023
Publicly Available Date Oct 18, 2023
Journal Geomechanics and Geophysics for Geo-Energy and Geo-Resources
Print ISSN 2363-8419
Electronic ISSN 2363-8427
Publisher Springer
Peer Reviewed Peer Reviewed
Volume 9
Issue 1
Article Number 107
DOI https://doi.org/10.1007/s40948-023-00634-z
Keywords Economic Geology; General Energy; Geophysics; Geotechnical Engineering and Engineering Geology
Public URL https://durham-repository.worktribe.com/output/1805893

Files

Published Journal Article (4.1 Mb)
PDF

Licence
http://creativecommons.org/licenses/by/4.0/

Publisher Licence URL
http://creativecommons.org/licenses/by/4.0/

Copyright Statement
Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.





You might also like



Downloadable Citations