If the average size of the droplets is large or if the flowage rate is low, they will settle and collect at the base of the komatiite komatiite and sulfide liquids may continue to flow, but the sulfide layer will have a low surface area to volume ratio and will be ineffective in extracting chalcophile elements from the overlying komatiite layer. If the average size of the droplets is small and/or the flowage rate is high, they may be carried in suspension in the flowing komatiite droplets have a large surface area to volume ratio and will be effective in scavenging chalcophile elements since they are carried by the turbulent motion of the flowing komatiite.
Turbulence causes coalescence of small droplets and breakup of large droplets, leading to an equilibrium droplet size.
The size of immiscible droplets and the interface between two immiscible layers are affected by inertial forces during turbulent flow. This interpretation has several implications for the mode of emplacement of sulfides, their degree of equilibration with the host komatiite, and the compositions of sulfide ores: (1) the solubility of sulfur in komatiite is relatively low, so most of the sulfide in eroded sediments will be melted and remain as a dense layer at the base of the flow or be incorporated into the turbulently flowing komatiite as immiscible sulfide droplets (2) sulfide ores will not necessarily be in equilibrium with overlying komatiites but will record equilibration with variably contaminated lavas during initial stages of emplacement and crystallization and (3) ore compositions will vary from channel to channel (shoot to shoot) depending on (i) the composition of the hybridized komatiite, (ii) the fluid dynamics of the system and the effective magma-sulfide ratio (R factor), and (iii) the sulfide/silicate partition coefficients under the prevailing conditions of temperature and f (sub O 2 ) /f (sub S 2 ).
Geochemical and Nd isotope data for the type area at Kambalda suggest that mineralized lava channels are less contaminated than barren flanking segments of the flow, owing to high discharge rates and continuous replenishment within the channel. Stratigraphic, volcanological, petrological, and fluid dynamic studies suggest that Archean komatiite-associated nickel sulfide deposits in Western Australia formed by thermal erosion of unconsolidated sulfidic sediments beneath channelized lava flows.