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The phenomenon of rocks moving under their own means has always fascinated both scientists and the nonscientists. 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 phenomenon of rocks moving under their own means has always fascinated both scientists and the nonscientists. 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 [[diapir]]s 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.

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 thorough these strata (for a review, see Day-Stirrat et al.<ref name=Daystirratetal_2010>Day-Stirrat, R. J., A. McDonnell, and L. J. Wood, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER02/CHAPTER02.HTM Diagenetic and seismic concerns associated with interpretation of deeply buried "mobile shales,"] ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 5–27.</ref>). 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 (see Day-Stirrat et al.<ref name=Daystirratetal_2010 />; Elsley and Tieman<ref name=Elsleyandtieman_2010>Elsley, G. R., and H. Tieman, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER05/CHAPTER05.HTM A comparison of prestack depth and prestack time imaging of the Paktoa complex, Canadian Beaufort MacKenzie Basin], ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 79–90.</ref>). In addition, 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.<ref name=Albertzetal_2010>Albertz, M., C. Beaumont, and S. J. Ings, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER03/CHAPTER03.HTM Geodynamic modeling of sedimentation-induced overpressure, gravitational spreading, and deformation of passive margin mobile shale basins], ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 29–62.</ref> 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.<ref name=Battanietal_2010>Battani, A., A. Prinzhofer, E. Deville, and C. J. Ballentine, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER13/CHAPTER13.HTM Trinidad mud volcanoes: The origin of the gas], ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 223–236.</ref><ref name=Delisleetal_2010>Delisle, G., M. Teschner, E. Faber, B. Panahi, I. Guliev, and C. Aliev, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER12/CHAPTER12.HTM First approach in quantifying fluctuating gas emissions of methane and radon from mud volcanoes in Azerbaijan], ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 209–222.</ref><ref name=Mcneiletal_2010>McNeil, D. H., J. R. Dietrich, D. R. Issler, S. E. Grasby, J. Dixon, and L. D. Stasiuk, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER11/CHAPTER11.HTM A new method for recognizing subsurface hydrocarbon seepage and migration using altered foraminifera from a gas chimney in the Beaufort-Mackenzie basin], ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], 195–208.</ref><ref name=Warrenetal_2010>Warren, J. K., A. Cheung, and I. Cartwright, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER10/CHAPTER10.HTM Organic geochemical, isotopic, and seismic indicators of fluid flow in pressurized growth anticlines and mud volcanoes in modern deep-water slope and rise sediments of offshore Brunei Darussalam: Implications for hydrocarbon exploration in other mud- and salt-diapir provinces,] ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 161–194.</ref> As with mobile salt, shale-cored structures are commonly closely associated with hydrocarbons in many basins around the world. In Henry et al.<ref name=Henryetal_2010>Henry, M., M. Pentilla, and D. Hoyer, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER04/CHAPTER04.HTM Observations from exploration drilling in an active mud volcano in the southern basin of Trinidad, West Indies], ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 63–78.</ref>, information on the character of these strata can be found as well as documentation on drilling into mobile mud-cored anticlinal features (diapirs) in southern Trinidad.

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 thorough these strata (for a review, see Day-Stirrat et al.<ref name=Daystirratetal_2010>Day-Stirrat, R. J., A. McDonnell, and L. J. Wood, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER02/CHAPTER02.HTM Diagenetic and seismic concerns associated with interpretation of deeply buried "mobile shales,"] ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 5–27.</ref>). 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 (see Day-Stirrat et al.<ref name=Daystirratetal_2010 />; Elsley and Tieman<ref name=Elsleyandtieman_2010>Elsley, G. R., and H. Tieman, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER05/CHAPTER05.HTM A comparison of prestack depth and prestack time imaging of the Paktoa complex, Canadian Beaufort MacKenzie Basin], ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 79–90.</ref>). In addition, 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.<ref name=Albertzetal_2010>Albertz, M., C. Beaumont, and S. J. Ings, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER03/CHAPTER03.HTM Geodynamic modeling of sedimentation-induced overpressure, gravitational spreading, and deformation of passive margin mobile shale basins], ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 29–62.</ref> 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.<ref name=Battanietal_2010>Battani, A., A. Prinzhofer, E. Deville, and C. J. Ballentine, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER13/CHAPTER13.HTM Trinidad mud volcanoes: The origin of the gas], ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 223–236.</ref><ref name=Delisleetal_2010>Delisle, G., M. Teschner, E. Faber, B. Panahi, I. Guliev, and C. Aliev, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER12/CHAPTER12.HTM First approach in quantifying fluctuating gas emissions of methane and radon from mud volcanoes in Azerbaijan], ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 209–222.</ref><ref name=Mcneiletal_2010>McNeil, D. H., J. R. Dietrich, D. R. Issler, S. E. Grasby, J. Dixon, and L. D. Stasiuk, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER11/CHAPTER11.HTM A new method for recognizing subsurface hydrocarbon seepage and migration using altered foraminifera from a gas chimney in the Beaufort-Mackenzie basin], ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], 195–208.</ref><ref name=Warrenetal_2010>Warren, J. K., A. Cheung, and I. Cartwright, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER10/CHAPTER10.HTM Organic geochemical, isotopic, and seismic indicators of fluid flow in pressurized growth anticlines and mud volcanoes in modern deep-water slope and rise sediments of offshore Brunei Darussalam: Implications for hydrocarbon exploration in other mud- and salt-diapir provinces,] ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 161–194.</ref> As with mobile salt, shale-cored structures are commonly closely associated with hydrocarbons in many basins around the world. In Henry et al.<ref name=Henryetal_2010>Henry, M., M. Pentilla, and D. Hoyer, 2010, [http://archives.datapages.com/data/specpubs/memoir93/CHAPTER04/CHAPTER04.HTM Observations from exploration drilling in an active mud volcano in the southern basin of Trinidad, West Indies], ''in'' L. Wood, ed., Shale tectonics: [http://store.aapg.org/detail.aspx?id=1023 AAPG Memoir 93], p. 63–78.</ref>, information on the character of these strata can be found as well as documentation on drilling into mobile mud-cored anticlinal features (diapirs) in southern Trinidad.

* Shale may flow laterally but will develop overhangs of less than 6 km (3.7 mi). In contrast, salt overhangs may be on the order of tens of kilometers.

* Shale may flow laterally but will develop overhangs of less than 6 km (3.7 mi). In contrast, salt overhangs may be on the order of tens of kilometers.

* Ductile behavior of shales is unlikely above 80&deg;C (176&deg;F), and brittle behavior is more likely. Therefore, this temperature will provide a plasticity [[basement]] within a basin to constrain interpretation of tectonically active shales.

* Ductile behavior of shales is unlikely above 80&deg;C (176&deg;F), and brittle behavior is more likely. Therefore, this temperature will provide a plasticity [[basement]] within a basin to constrain interpretation of tectonically active shales.

* Salt volumes tend to be underestimated in interpretations of seismic data. In contrast, shale mass volumes are commonly overestimated by geophysical interpreters (Van Rensbergen and Morley<ref name=Vanrensbergenandmorley_2003>Van Rensbergen, P., and C. K. Morley, 2000, [http://www.sciencedirect.com/science/article/pii/S026481720000026X 3D seismic study of a shale expulsion syncline at the base of the Champion Delta, offshore Brunei and its implications for the early structural evolution of large delta systems]: Marine and Petroleum Geology, v. 17, p. 861–872.</ref>) because of the manner in which geophysical data are processed. The apparent pull-up of beds around shale diapirs is caused by overmigration of the shale mass and treating its velocity as one would a salt.

* Salt volumes tend to be underestimated in interpretations of seismic data. In contrast, shale mass volumes are commonly overestimated by geophysical interpreters (Van Rensbergen and Morley<ref name=Vanrensbergenandmorley_2003>Van Rensbergen, P., and C. K. Morley, 2000, [http://www.sciencedirect.com/science/article/pii/S026481720000026X 3D seismic study of a shale expulsion syncline at the base of the Champion Delta, offshore Brunei and its implications for the early structural evolution of large delta systems]: Marine and Petroleum Geology, v. 17, p. 861–872.</ref>) because of the manner in which geophysical data are processed. The apparent pull-up of beds around shale [[diapir]]s is caused by overmigration of the shale mass and treating its velocity as one would a salt.

==Future directions==

==Future directions==