 Alternately, SedEx deposits may be sourced from magmatic fluids from subseafloor magma chambers and hydrothermal fluids generated by the heat of a magma chamber intruding into saturated sediments.This scenario is relevant to mid-ocean ridge environments and volcanic island arcs where black smokers are formed by discharging hydrothermal fluids.Upon mixing of the ore fluids with the seawater, dispersed across the seafloor, the ore constituents and gangue are precipitated onto the seafloor to form an orebody and mineralization halo which are congruent with the underlying stratigraphy and are generally fine grained, finely laminated and can be recognized as chemically deposited from solution.