Print this pageDeformation in and Around Mud Volcano Feeder Complexes
Mud volcanoes are an important global mechanism for the escape of fluid and gasses from sedimentary basins. However, little is known about the structural deformation inflicted by their intrusion through the surrounding country rock. Structural mapping of large, onshore mud volcanoes located in Azerbaijan, reveals the first model of deformation caused by these intrusive mud systems. The systems mapped have contiguous blocks of country rock within the feeder complexes, which are normally buried by extrusive material. Feeder complexes were located within 1 km of the axes of NW-SE trending folds associated with the southern margin of the Great Caucasus mountain belt. The mapping shows that the intrusive complexes are 200 m to 800 m wide and roughly circular. We identify various forms of intrusion including grid like fractures sets, sinuous fractures, mud plugs and breccia pipes that compose the ‘feeder complexes’. These mud volcano feeder complexes are dominated by intrusive mud fill, but also contain significant blocks of country rock that are 1-20 m in length with strike orientations that vary up to 90° relative to that of the surrounding sedimentary strata. The 'feeder complexes' can be subdivided into different structural zones; the ‘un-intruded zone’, ‘peripheral fracture zone’, ‘central zone of block rotation’, and the ‘active vent zone'. This study provides a basis for understanding the extent and style of structural damage around mud volcanoes and also constrains conduit geometry for modelling studies of mud volcano evolution and flow dynamics.
AAPG Search and Discover Article #90100©2009 AAPG International Conference and Exhibition 15-18 November 2009, Rio de Janeiro, Brazil