Mantle compositional control on the extent of mantle melting, crust production, gravity anomaly, ridge morphology, and ridge segmentation: a case study at the Mid-Atlantic Ridge 33¯35°N

Magmatic sulfide deposits result from transport and settling of dense sulfide liquid droplets in basic magma. To model these processes, we carried out analog experiments in which dense silicone oil droplets were transported in a viscous aqueous polymer solution. The results of the experiments indicate that sulfide droplets can be carried in suspension by magma flowing at typical velocities. Due to the large surface tension of sulfide droplets, coalescence does not occur during transport. Transport ceases when upward magma velocity decreases because of conduit enlargement or change from vertical to horizontal flow. Coalescence of droplets is controlled by magma viscosity and the presence of crystals.