Scanning and transmission electron microscopic analyses of shale samples from offshore Louisiana, USA, Gulf of Mexico, reveal the relationship between mineralogical and microfabric changes during burial diagenesis. The local geopressured zone begins at 2200-m depth. Above that depth the shales are smectite-rich, generally lack particle orientation, and contain appreciable pores. Below the 2200-m depth, the shales become more illiterich with increasing burial, more crystalline, and less porous. Microfabric changes are mainly caused by compaction during burial diagenesis; mineralogical changes (smectite-to-illite) and crystal growth also play an important role in fabric alteration during deep burial diagenesis.
|Number of pages||7|
|Publication status||Published - 1999|
Bibliographical noteFunding Information:
Acknowledgments We thank Tom Wilson of Shell Offshore Inc., New Orleans, Louisiana, USA, for providing us with the samples, and Dr. Ray N. Guillemette for his assistance in microprobe work. We also acknowledge financial support from Integrated Reservoir Investigation Project (IRIP).
All Science Journal Classification (ASJC) codes
- Environmental Science (miscellaneous)
- Geotechnical Engineering and Engineering Geology
- Earth and Planetary Sciences (miscellaneous)