Other
Scientific paper
Jun 1986
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1986gecoa..50.1151n&link_type=abstract
Geochimica et Cosmochimica Acta, vol. 50, Issue 6, pp.1151-1158
Other
6
Scientific paper
Oxygen transport rates along lamellar boundaries in a macroperthitic feldspar have been measured using an ion microprobe. Perthite samples were exchanged hydrothermally with 18 O-enriched water at temperatures of 500° to 700°C and at a pressure of 1 kb. Step-scanning traverses along grain boundaries were made with the ion microprobe on surfaces which were cut to show interior faces of the samples. Volume diffusion profiles were determined from step-scanning traverses as well as from depth-profiles. Volume diffusion coefficients for oxygen as determined by step-scanning are given by D 0 = 8.0( +290 -7.8 ) × 10 -9 cm 2 -sec -1 and Q v = 20 ± 7 kcal-mol -1 . As determined by depth-profiling, volume diffusion coefficients are given by D 0 = 1.5( +72 -1.3 ) × 10 -8 cm 2 -sec -1 and Q v = 26 ± 3 kcal-mol -1 . The products of the lamellar boundary diffusion coefficients times the boundary widths, calculated using the volume diffusion coefficients determined by depth-profiling, are given by D 0 = 4.7( +240 -4.6 ) × 10 -6 cm 3 -sec -1 and Q b = 43 ± 7 kcal-mol -1 . The grain boundary diffusion coefficients measured for oxygen (or possibly water) in the perthite are at least 10 4 times the volume diffusion coefficients. Due to the tightness of the noncoherent lamellar boundary, these data define a lower bound to grain boundary diffusion coefficients for oxygen and perhaps other species in silicates in hydrothermal systems.
Giletti Bruno J.
Nagy Kalman L.
No associations
LandOfFree
Grain boundary diffusion of oxygen in a macroperthitic feldspar does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Grain boundary diffusion of oxygen in a macroperthitic feldspar, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Grain boundary diffusion of oxygen in a macroperthitic feldspar will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1832589