High-pressure falling sphere viscosimetry of basaltic and dacitic rocks in conjunction with synchrotron radiation

Abstract

In situ falling-sphere technique viscosity measurements in a DIA-type multi-anvil apparatus-MAX80 at beamline F2.1 at DESY / HASYLAB, Hamburg, Germany-have been performed. The viscosity was measured following Stokes law by evaluation of X-radiography sequences taken by a CCD-camera. Powdered basalt, dacite, and diabase samples were measured at pressures of 0.5 and 1 GPa and temperatures of 1890 K. After pressurization the temperature produced by an internal graphite heater was increased up to sample melting observed by X-ray diffraction and X-radiography. The results cover a data range from 3.5 Pa s (basalt at 1 GPa) and 195.5 Pa s (diabase at 0,5 GPa) and are in good agreement with published data.