Three-Dimensional Reconstruction of Marine Clay Nano- and Microstructure By Transmission Electron Microscopy: Analysis of Fabric and Pore Network

<p>Three-dimensional reconstructions of marine fine-grained sediment open a new dimension for studying nano- and microscale organo-clay fabric important to improving and advancing organic matter (OM) sequestration and fluid flow dynamics modeling. I created 3-D reconstructions of clay fabric and pore pathways from serial sections and photographic mosaics obtained using transmission electron microscopy. These reconstructions show aggregations of clay domains, surrounding OM, and pore networks. I examined a Model sample (laboratory consolidated) with 1% OM and a Natural sample (polychaete fecal pellet) with high levels of OM. Three-dimensional reconstructions were segmented into 300 nm cube subsamples to make highly localized qualitative observations and quantitative measurements of porosity, particle and pore orientation and volume, and pore network tortuosity.</p> <p>Flow pathway spreadsheet maps were created based on pore size and orientation. This technique allows tortuosity to be calculated for 3-D reconstructions while restricting porosity to a minimum boundary condition prior to determining tortuous pathways. Measurements of 2-D photographs and 3-D reconstructions using the same serial photographs showed that pathlengths measured for tortuosity were for the most part statistically similar. The range of porosities and the number of pathways through which flow could pass through the sample are significantly higher in 3-D analyses. Thus, measurements made from 2-D sediment pathway studies provide limited information, omitting a significant number of diffusion and flow pathways that cannot be resolved in two dimensions.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Masters Thesis

Discipline thesis:degree_discipline

Biological Sciences

Year dc:date.available

2014

Author dc:creator

• Douglas, Jessica Rae Gardner

Contributors dc:contributor

• Kenneth J. Curry
• Richard H. Bennett
• Franklin T. Heitmuller

• clay fabric
• 3-D reconstruction
• transmission electron microscopy
• pore network
• nanometer scale
• marine sediment
• Biology
• Earth Sciences
• Life Sciences
• Physical Sciences and Mathematics
• Sedimentology

Repository record dc:identifier

https://aquila.usm.edu/masters_theses/7

OAI identifier oai:identifier

oai:aquila.usm.edu:masters_theses-1010