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Texas A&M University
Halbouty Rm 224
Department of Geology and Geophysics,
MS 3115,
College Station, Texas 77843

Dr. Andy Hajash

Professor

Texas A&M University, Ph.D., Geology, 1975

Florida State University, M.S., Geology, 1970

Florida State University, B.S., Geology, 1969

Research Interests

  • Experimental investigations of water/rock interactions in the subsurface:
    • Chemical and mechanical aspects of solution-transfer creep and pressure solution.
      • kinetics of pore-volume loss and mineral-water reactions at diagenetic temperatures and pressure with non-zero effective stress; effects of temperature, grain size, stress, strain, flow rate, and saturation state.
  • The effects of organic acids on porosity modification in sandstone reservoirs.    
    • role of carboxylic acids on mineral solubility, dissolution kinetics, pH-buffering, metal-ligand complexes, aluminum mobility, and generation of porosity.

Experience

  • Professor, Department of Geology and Geophysics, Texas A&M University, September 1993 – present.
  • Professor and Head, Department of Geology and Geophysics, Texas A&M University, January, 1999 – August, 2003.
  • Professor and Assistant Department Head, Department of Geology and Geophysics, Texas A&M University, June, 1996 – December 1998.
  • Professor, Department of Geology and Geophysics, Texas A&M University, College Station, Texas, December 1993.   
  • Associate Professor, Department of Geology, Texas A&M University, College Station, Texas, December 1981 - December 1993.
  • Consultant, Amoco Production Company, Tulsa, Oklahoma, June 1985 - August 1985.
  • Research Scientist, Senior Grade, Amoco Production Company, Tulsa Research Center, Tulsa, Oklahoma, June 1983 - August 1983.
  • Research Scientist, Senior Grade, Amoco Production Company, Tulsa Research Center, Tulsa, Oklahoma, June 1982 - August 1982.
  • Assistant Professor, Department of Geology, Texas A&M University, College Station, Texas, May 1975 - December 1981.

Awards

  • Distinguished Achievement Award in Teaching (University Level) by the Association of Former Students of Texas A&M University (2002)
  • Invited by Professor Zhengyu BAO to visit the Department of Geochemistry, China University of Geosciences in Wuhan, PRC (1998)

Selected Publications

  • Karner, S. L., A. K. Kronenberg, F. M. Chester, J. S. Chester, and A. Hajash, Jr. (2008), Hydrothermal deformation of granular quartz sand, Journal of Geophysical Research, 113, B05404, doi:10.1029/2006JB004710.
  • He, Wenwu, Sparks, D., and Hajash, A. (2007) Evolution of Fluid Chemistry in Quartz Compaction Systems: Experimental Investigations and Numerical Modeling, Geochim. et Cosmochim. Acta., vol. 71, 4846-4855.   Submitted to Geochimica et Cosmochimica Acta, October, 2006, Revised manuscript submitted July 2007, Accepted August, 2007, published October 2007
  • Chester, F. M., J. S. Chester, A. K. Kronenberg, and A. Hajash (2007), Subcritical creep compaction of quartz sand at diagenetic conditions: Effects of water and grain size, J. Geophys. Res., 112, B06203, doi:10.1029/2006JB004317.
  • Karner, S. L., Chester, J. S., Chester, F. M., Kronenberg, A. K, and Hajash, A., 2005, Laboratory deformation of granular quartz sand: Implications for the burial of clastic rocks, Am. Assoc. Petrol. Geol. Bulletin, v. 85, 603-625.
  • He, W, Hajash, A., and Sparks, D., 2003, Creep compaction of quartz aggregates: Effect of pore-fluid flow rates – A combined experimental and theoretical study, American Journal Science, v. 303, 73-93.
  • He, W. Hajash, A., and Sparks, D., 2002, A model for porosity evolution during compaction of sediments, Earth and Planetary Science Letters, v. 197, 237-244.
  • Hajash, A., Carpenter, T. D, and, Dewers, T. A, 1998, Dissolution and time-dependent compaction of albite sand: Experiments at 100° and 160°C in pH-buffered organic acids and distilled water, Tectonophysics, v. 295, 93-115.
  • Dewers, T. A. and Hajash, A. 1995, Rate laws for water-assisted compaction and stress-induced water-rock interaction in sandstones, J. Geophys. Res., Vol. 100, pp. 13,093-13,112.

Affiliations

  • Geological Society of America
  • American Geophysical Union
 
College of Geosciences Atmospheric Science Geography Oceanography Geology & Geophysics Environmental Programs Water Degree Program GERG IODP Texas Sea Grant Department Icons