Abstract
Ion microprobe analyses of trace elements in quartz from the Santa Catalina mylonite zone, southern Arizona, show a wide range in Li contents and little or no variaiton in B, Na, Al, K, and Fe. One large quartz crystal is protected on three sides by a partially altered alkali feldspar crystal. The fourth side grades into small recrystallized quartz grains (perpendicular to the c-axis); a step scan parallel to the c-axis shows an approximately bell-shaped curve for the distribution of Li. The fluid accompanying mylonitic deformation appears to have partially leached the quartz of Li. Given temperature estimates of mylonitization for this sample of ~500°C, diffusion coefficients estimated from the observed concentration profiles appear to be at least 7-10 orders of magnitude smaller than experimentally determined coefficients, suggesting that 1) alkali metal diffusion in quartz in nature takes place via a different diffusion mechanism than measured in the laboratory, or 2) a hydrous fluid is required to increase diffusion rates for Li and this fluid was absent during much of the mylonitic event. -Authors
Original language | English (US) |
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Pages (from-to) | 343-350 |
Number of pages | 8 |
Journal | Journal of Geology |
Volume | 97 |
Issue number | 3 |
DOIs | |
State | Published - Jan 1 1989 |
ASJC Scopus subject areas
- Geology