The role of shear stress in mobilizing deep-seated mud volcanoes: geological and geomechanical evidence from Trinidad and Taiwan

Abstract

Abstract Deep-seated mud volcanoes are observed in a variety of geological settings, which has led to considerable debate on their origin. This paper summarizes the geological features common to mud volcanoes around the world and possible mechanisms of their extrusion. Field and laboratory data from Trinidad and Taiwan are discussed to assess the possible sources and causes of the volcanoes. A close association between mud volcanoes and compressional tectonics leads to the conclusion that tectonic activity plays an important part in mud volcano development. Experimental data are presented to explain the role of tectonic activity and the association between shear stresses and mud volcanoes. It is demonstrated that shear stresses applied to low permeability sediments can produce a dramatic increase in pore pressure and can cause sediment flow. This is proposed as one possible contributing cause of mud volcanoes.