pure and applied geophysics

, Volume 117, Issue 1–2, pp 227–241 | Cite as

The linear relation between temperatures based on the silica content of groundwater and regional heat flow: A new heat flow map of the United States

  • Chandler A. Swanberg
  • Paul Morgan
Exploration, Characterisation and Exploitation of Geothermal Resources


Application of the silica geothermometer to over 70,000 non-thermal groundwaters from the United States has shown that there is a correlation between the average silica geotemperatures for a region (T SiO2 in °C) and the known regional heat flow (q in mW m−2) of the form:
$$TSiO_2 = mq + b$$

wherem andb are constants determined to be 0.67°C m2 mW−1 and 13.2°C respectively. The physical significance of ‘b’ is the mean annual air temperature. The slope ‘m’ is related to the minimum average depth to which the groundwaters may circulate. This minimum depth is estimated to be between 1.4 and 2.0 km depending on the rock type. A preliminary heat flow map based on equation (1) is presented using theT SiO2 for new estimates of regional heat flow where conventional data are lacking. Anomalously high localT SiO2 values indicate potential geothermal areas.

Key words

Silica geothermometer Regional heat flow Geothermal energy Ground water circulation United States 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. AAPG-USGS,Subsurface Temperature Map of North America (U.S. Geol. Survey, Arlington, Virginia, 1976).Google Scholar
  2. Blackwell, D. D.,The thermal structure of the continental crust, inThe Structure and Physical Properties of the Earth's Crust, Geophys. Monogr. ser., vol. 14 (ed. J. G. Heacock) (Am. Geophys. Un., Washington, D.C., 1971), pp. 169–184.Google Scholar
  3. Costain, J. K., Glover III, L. andSinha, A. K.,Evaluation and targeting of geothermal energy resources in the southeastern United States, inVir. Poly. Tech. Prog. Rept. VPI-SU-5103-3 (Blacksburg, Virginia, 1977).Google Scholar
  4. Fournier, R. O. andRowe, J. J. (1966),Estimation of underground temperatures from the silica content of water from hot spring and wet steam wells, Amer. Jour. Sci.264, 685–697.Google Scholar
  5. Fournier, R. O., White, D. E. andTruesdell, A. H. (1974),Geochemical indicators of subsurface temperature, 1, Basic Assumptions: Jour. Res. U.S. Geol. Sur.2, 259–262.Google Scholar
  6. Mariner, R. H. andWilley, L. M. (1976),Geochemistry of thermal waters in Long Valley, Mono County, California, Jour. Geophys. Res.81, 792–800.Google Scholar
  7. Reiter, M., Edwards, C. L., Hartman, H. andWeidman, C. (1975),Terrestrial heat flow along the Rio Grande Rift, New Mexico and Southern Colorado, Geol. Soc. Amer. Bull.86, 811–818.Google Scholar
  8. Rimstidt, J. D. (1977),Kinetic evaluation of the quartz geothermometer, abs. Geol. Soc. Am. Ann. Mtg., pp. 1142–1143.Google Scholar
  9. Sass, J. H., Diment, W. H., Lachenbruch, A. H., Marshall, B. V., Munroe, R. J., Moses, T. H., Jr andUrban, T. C.,A new heat flow contour map of the conterminous United States, inU.S. Geol. Survey, openfile Rpt. 76-756 (Menlo Park, California, 1976), 24 pp.Google Scholar
  10. Swanberg, C. A., andAlexander, S.,The use of the random groundwater data from WATSTORE in geothermal exploration: An example from the Imperial Valley, California (in press).Google Scholar
  11. Swanberg, C. A. andStoyer, C. H. (1976),The correlation among water chemistry, regional heat flow, and the geothermal potential of Arizona, abs. Soc. Exp. Geophys., Ann. Mtg., Oct. 23–28, p. 93.Google Scholar
  12. Swanberg, C. A., Morgan, P., Stoyer, C. H. andWitcher, J. C. (1977),An appraisal study of the geothermal resources of Arizona and adjacent areas in New Mexico and Utah and their value for desalination and other uses, inNew Mex. Energy Inst. Rpt. 006 (Las Cruces, New Mexico, 1977), 76 pp.Google Scholar
  13. Truesdell, A. H.,Summary of Section III, Geochemical techniques in exploration, inProc. 2nd U.N. Sump. on the Development and Use of Geothermal Resources, San Francisco, 1975, vol. 1 (1976), pp. liii-lxxix.Google Scholar
  14. Truesdell, A. H. andFournier R. O. (1977),Procedure for estimating the temperature of a hot water component in a mixed water using a plot of dissolved silica vs. enthalpy, Jour. Res. U.S. Geol. Survey,5, 49–52.Google Scholar
  15. White, D. F. andWilliams, D. L.,Assessment of Geothermal Resources of the United State-1975, U.S. Geol. Survey, Circ., 725 (1975), 155 pp.Google Scholar
  16. Young, H. W. andMitchell, J. C. (1973),Geothermal investigations in Idaho, part I, Geochemistry and geologic setting of selected thermal waters, Idaho Dept. Water Admin., Water Info., Bull.30, 43 pp.Google Scholar

Copyright information

© Birkhäuser Verlag 1978

Authors and Affiliations

  • Chandler A. Swanberg
  • Paul Morgan
    • 1
  1. 1.Departments of Earth Sciences and PhysicsNew Mexico State UniversityLas CrucesUSA

Personalised recommendations