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Petrographic And Physical Factors Controlling Thermal-Conductivity Of Granitic-Rocks In Illinois Deep Holes Uph 1, 2, And 3, Yoram Eckstein, Peter Dahl, Charles J. Vitaliano
Petrographic And Physical Factors Controlling Thermal-Conductivity Of Granitic-Rocks In Illinois Deep Holes Uph 1, 2, And 3, Yoram Eckstein, Peter Dahl, Charles J. Vitaliano
Peter Dahl
Twenty-four granitic core samples from the Illinois deep drill holes yield thermal conductivity values in the range 29.3–37.6 mW/cm °C, wet bulk densities in the range 2.608–2.960 g/cm3, and water accessible porosity in the range 0.12–0.78%. Thermal conductivity values vary with modal quartz content of the rocks at all depths, and both parameters decrease linearly with depth between 673 and 1016 m in drill hole UPH 3. Below 1070 m there is no systematic variation in modal quartz content with depth and hence no systematic variation in thermal conductivity. Similarly, no systematic variations in modal quartz or physical …
Influence Of F(Oh)(-1) Substitution On The Relative Mechanical Strength Of Rock-Forming Micas, Peter Dahl, Michael J. Dorais
Influence Of F(Oh)(-1) Substitution On The Relative Mechanical Strength Of Rock-Forming Micas, Peter Dahl, Michael J. Dorais
Peter Dahl
Microtextural and experimental studies have yielded conflicting data on the relative mechanical strengths of muscovite and biotite [Wilson and Bell, 1979; Kronenberg et al., 1990; Mares and Kronenberg, 1993]. We propose a crystal-chemical resolution to this conflict, namely, that (001) dislocation glide in biotite is rate-limited by its fluorine content. Significant F(OH)−1 substitution, and concomitant removal of hydroxyl H+ directed into the interlayer cavity, potentially increases mechanical strength of biotite in two ways: (1) it eliminates K+-H+repulsion, thereby strengthening the interlayer bonds, and (2) it allows K+ to “sink” …