A ROTATING AUTOCLAVE FOR CENTRIFUGE STUDIES - FALLING SPHERE VISCOMETRY

The design and construction of a rotating autoclave are presented for in situ studies of silicate melts and partially molten samples at elev ated temperatures and pressures, as well as at elevated accelerations. As an example of its utility, the first results obtained for the visc osity of DGG-1 glass under pressure are presented. This device will en able the determination of the viscosity of volatile-bearing silicate m elts in the mid- to high-viscosity range (10(6)-10(9) Pa s) that is ot herwise very difficult to access. Additionally, experimental investiga tions of physics and chemistry of the segregation of water-bearing mel ts from partially molten rocks under conditions of enhanced accelerati on are now possible.