Preprints
https://doi.org/10.5194/egusphere-2024-2511
https://doi.org/10.5194/egusphere-2024-2511
22 Aug 2024
 | 22 Aug 2024

Measuring varve thickness using µCT: a comparison with thin section

Marie-Eugénie Meusseunan Pascale Jamba, Pierre Francus, Antoine Gagnon-Poiré, and Guillaume St-Onge

Abstract. X-ray micro-computed tomography (μCT) scans were performed on four varved sediment cores collected in Grand Lake (Labrador) and previously studied with thin sections. These scans allowed to investigate the possibility of using µCT as a substitute for thin sections to carry out counts and thickness measurements of varved sediments. Comparing varve counts of these two methods, μCT counts are slightly higher than the ones made with thin sections. The difference in counts suggests that the petrographic study and a SEM analysis of a thin section remain necessary for determining the varve character of the laminae. Yet, µCT allows measurements in multiple directions, improving the robustness of the counts and allowing avoiding the manufacturing of continuous thin sections along sediment sequence.

As to the thickness measurement, the µCT analyses were made in two perpendicular directions. Not surprisingly, measurements made on the same cutting plane as the thin section are quite similar to the ones made on the latter. However, there are significant differences with measurements made on the perpendicular plane. This highlights the need to perform varve thickness measurements in at least two perpendicular directions for better estimates of varved sediment thicknesses. In addition, the study illustrates that µCT is an effective way to select the least deformed zones with parallel varves to carry out the best possible thickness measurements.

Publisher's note: Copernicus Publications remains neutral with regard to jurisdictional claims made in the text, published maps, institutional affiliations, or any other geographical representation in this preprint. The responsibility to include appropriate place names lies with the authors.
Marie-Eugénie Meusseunan Pascale Jamba, Pierre Francus, Antoine Gagnon-Poiré, and Guillaume St-Onge

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on egusphere-2024-2511', Anonymous Referee #1, 16 Sep 2024
    • AC1: 'Reply on RC1', Marie-eugénie Jamba, 23 Sep 2024
  • RC2: 'Comment on egusphere-2024-2511', Anonymous Referee #2, 06 Oct 2024
    • AC2: 'Reply on RC2', Marie-eugénie Jamba, 21 Oct 2024
Marie-Eugénie Meusseunan Pascale Jamba, Pierre Francus, Antoine Gagnon-Poiré, and Guillaume St-Onge
Marie-Eugénie Meusseunan Pascale Jamba, Pierre Francus, Antoine Gagnon-Poiré, and Guillaume St-Onge

Viewed

Total article views: 333 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
192 61 80 333 7 6
  • HTML: 192
  • PDF: 61
  • XML: 80
  • Total: 333
  • BibTeX: 7
  • EndNote: 6
Views and downloads (calculated since 22 Aug 2024)
Cumulative views and downloads (calculated since 22 Aug 2024)

Viewed (geographical distribution)

Total article views: 334 (including HTML, PDF, and XML) Thereof 334 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 06 Dec 2024
Download
Short summary
This article presents a non-destructive method for studying laminated sediments with X-ray computed tomography (μCT). It aims to study the possibility of using μCT as an analytical tool to analyse varved sediments in the context of paleoclimatic studies. As results, µCT offers the possibility of to do fasts analysis and constitutes a powerful tool to improve the quality of results through the access of a 3D view allowing choosing the most representative part of varved record.