Sharing similar lithologic characteristics with dolomite seam hosting MVT Pb-Zn sulfide ores
hydrothermal dolomite reservoirs contains mainly massive-matrix-replacement dolomites and void-or fracture-filling saddle dolomite dotted with small amount of other hydrothermal ores
such as sphalerite
galena
quartz
pyrite
barite
and fluorite.Saddle dolomite-filling microfractures and zebra textures formed by shear stress and dolomite breccias are also common in these reservoirs.Unfilled vugs
fractures
and pores from differential dissolution of the original carbonates(mainly limestone)provide the necessary spaces for later hydrocarbon charges.The hydrothermal fluids preferentially flow upwards along the extensional and transtensional fault systems
where dolomitization preferentially occurs on the hanging walls and extends laterally in the course of fault propagation.The hydrothermal dolomite reservoir can be well characterized and predicted through high-resolution seismic attribute analysis and imaging.