 Black smoker chimneys are also common, as are seepage mounds of chert, jaspilite and sulfides.One of the major problems in classifying SedEx deposits is in identifying whether or not the ore was definitively exhaled into the ocean and whether the source was formational brines from sedimentary basins.In the majority of cases the overprint of metamorphism and faulting, generally thrust faulting, deforms and disturbs the sediments and obscures sedimentary features, although this is generally patchy so that the original configuration will be seen within the deposit.