A b s t r a c t The variation of silicate dissolution and crystallization rates with chemical affinity and solution composition can be quantified by the identification of the rate controlling precursor complex. The nature of this complex depends on the individual mineral structure. Specifically, the destruction of quartz and anorthite frameworks requires the breaking of only one type of structu...

General lattice vibrational properties of minerals, particularly those properties which strongly influence the thermodynamic behavior, are discussed in this paper (the second of a series relating thermodynamic and lattice vibrational properties of minerals). Infrared (IR), Raman (R), and inelastic neutron scattering (INS) data are summarized, if known, for the following minerals: halite (INS), ...

Recent work in Barrovian metamorphic terranes has found that rocks experience peak metamorphic temperatures across several grades at similar times. This result is inconsistent with most geodynamic models of crustal over-thickening and conductive heating, wherein rocks which reach different metamorphic grades generally reach peak temperatures at different times. Instead, the presence of addition...

The production rate of cosmogenic He in apatite, zircon, kyanite and garnet was obtained by cross-calibration against Be in co-existing quartz in glacial moraine boulders from the Nepalese Himalaya. The boulders have Be ages between 6 and 16 kyr and span elevations from 3200 to 4800 m. In all of these minerals He correlates with Be and is dominantly cosmogenic in origin. After modest correction...

R.T. Downs Department of Geosciences, University of Arizona, Tucson, Arizona 85721, USA Abstract The unit-cell dimensions and crystal structure of sillimanite at various pressures up to 5.29 GPa have been refined from single-crystal X-ray diffraction data. As pressure increases, a and b decrease linearly, whereas c decreases nonlinearly with a slightly positive curvature. The axial compression ...

The Aegean Sea area is thought to be an actively extending back-arc region, north of the present day Hellenic volcanic arc and north-dipping subduction zone in Eastern Mediterranean. shows extensive normal faulting, ductile ‘extensional’ shear zones extensional S-C fabrics throughout islands that have previously been related regional extension associated with slab rollback on Subduction Zone. I...