Exhalative deposits are mineral deposits formed from the precipitation of minerals from hydrothermal fluids that are expelled onto the seafloor, typically associated with volcanic activity. These deposits are important in understanding the formation of massive sulfide deposits and other hydrothermal ore deposits.
Reference: Franklin, J. M., Gibson, H. L., Jonasson, I. R., & Galley, A. G. (2005). “Volcanogenic Massive Sulfide Deposits.” Economic Geology 100th Anniversary Volume, 523-560.