Year: 2000
Type: article
Abstract: Silicon diffusion rates were determined in fine‐grained (∼4.5 µm) hot‐pressed forsterite aggregates at 900° to 1200°C and 0.1 MPa using a 30Si‐tracer and standard SIMS analysis. There is no measurable difference in diffusion rates between samples buffered by excess MgO or SiO2, nor samples run in dry N2 or H2/CO2. The results yield the Arrhenius parameters D0, bulk = 5.4 × 10−9 m²/sec and Q = 203±36 kJ/mol. At 1200°C, the grain boundary diffusion rate of 30Si is similar to 26Mg (Si ∼10 times greater), ∼10² less than Fe, and ∼105 less than O. In addition, the 30Si grain boundary diffusion rate is ∼109 greater than the Si volume diffusion rate and indicates that diffusional transport of Si in forsterite aggregates is dominated by grain boundaries.
Source: Geophysical Research Letters
DOI: 10.1029/2000gl008492
Authors: John R. Farver, Richard A. Yund
Institutions: Bowling Green State University, Brown University
Language: English
Subfield: Geophysics
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: bronze
Funder: U.S. Department of Energy
OpenAlex ID: W2040528877