Memoir 93: Shale Tectonics

The phenomenon of rocks moving under their own means has always fascinated both scientists and nonscientists alike. Salt is known to extrude and flow as a result of differences in density of the material and surrounding sediments. However, movement of fine-grained clastics as intrusive injectites or diapirs or as extrusive eruptive sand blows or mud volcanoes has captured the public’s imagination and given scientists the impetus to reconsider the physics of how sediments behave in the subsurface.  

The 2008 AAPG Hedberg Conference on Mobile Shale Basins was held in response to a need to gather industry and academic communities in a common forum to address the very existence of mobile shales. Stimulating and informative discussions at that Conference led to this Memoir on shale tectonics. 

The volume documents shale tectonics from a variety of basins around the world, including the southern Beaufort Sea; the Krishna-Godavari Basin, India; the Niger Delta; eastern offshore Trinidad; offshore Brunei; and along the Spanish arm of the Mediterranean Sea. In addition, included are chapters covering all of the following shale tectonic topics: 

• Because of the burgeoning of shale gas and shale oil research, geoscientists are gaining a better understanding of the petrographic framework of shales, as well as their behavior under various pressure and temperature regimes and the manner in how fluids move through these strata.  
• Advances in seismic imaging and processing technologies illuminate stratal geometries associated with shale tectonics that have led to a new understanding of the processes responsible for the geometries we observe in shale strata.  
• Advances in modeling and understanding of how both muds and shales behave after burial have led to new geodynamic models for interpreting process from response reflected in stratal packages.  
• Field geoscientists have added to our understanding of the geochemistry and physical character of extrusive mud features and their relationship to the overall basin hydrocarbon system.  
• As with mobile salt, shale-cored structures are commonly closely associated with hydrocarbons in many basins around the world.  

In addition to works from authors who attended the Hedberg Conference, this volume also contains articles from authors who did not have an opportunity to present their work at the meeting, and thus contains a representative cross section of the most current research and understanding regarding shale tectonics.