HR: 1340h
AN: T53C-1454    [Abstracts]
TI: Experimental Investigation of the Dissolution of Quartz by a Muscovite Mica Surface: Implications for Pressure Solution
AU: * Meyer, E E
EM: emmo@engr.ucsb.edu
AF: University of California, Santa Barbara, UCSB, Santa Barbara, CA 93106 United States
AU: Greene, G W
EM: wren@engr.ucsb.edu
AF: University of California, Santa Barbara, UCSB, Santa Barbara, CA 93106 United States
AU: Alcantar, N A
EM: alcantar@eng.usf.edu
AF: University of South Florida, 4202 E. Fowler Avenue, Tampa, FL 33620 United States
AU: Israelachvili, J N
EM: jacob@engr.ucsb.edu
AF: University of California, Santa Barbara, UCSB, Santa Barbara, CA 93106 United States
AU: Boles, J R
EM: boles@geol.ucsb.edu
AF: University of California, Santa Barbara, UCSB, Santa Barbara, CA 93106 United States
AB: Using the Surface Forces Apparatus, which gives angstrom resolution of film thicknesses, we have measured dissolution of quartz sheets when pressed against muscovite mica surfaces in aqueous electrolyte solution, but no dissolution is observed when silica is pressed against silica under the same solution conditions and pressure. Initial dissolution rates in the quartz-muscovite experiments range from 10 to 40 angstroms/minute, depending on the shape (circular or elliptical) of the quartz- muscovite junction, and dissolution settles into a constant rate of approximately 0.1 angstroms/minute after several hours for all junction shapes. The dissolved quartz appears to reprecipitate outside the contact junction as a fragile silica gel, which may be the main factor limiting this rate of further dissolution. Rapid initial dissolution is seen despite the fact that these experiments are carried out at relatively low pressures (2-3 atm) and temperatures (25°C).
DE: 3630 Experimental mineralogy and petrology
DE: 3675 Sedimentary petrology
DE: 3902 Creep and deformation
DE: 3947 Surfaces and interfaces
SC: Tectonophysics [T]
MN: Fall Meeting 2005