International Journal of Earth Sciences

, Volume 97, Issue 2, pp 289–306 | Cite as

Estimates of heat flow and heat production and a thermal model of the São Francisco craton

Original Paper

Abstract

An updated analysis of geothermal data from the highland area of eastern Brazil has been carried out and the characteristics of regional variations in geothermal gradients and heat flow examined. The database employed includes results of geothermal measurements at 45 localities. The results indicate that the Salvador craton and the adjacent metamorphic fold belts northeastern parts of the study area are characterized by geothermal gradients in the range of 6–17°C/km. The estimated heat flow values fall in the range of 28–53 mW/m2, with low values in the cratonic area relative to the fold belts. On the other hand, the São Francisco craton and the intracratonic São Francisco sedimentary basin in the southwestern parts are characterized by relatively higher gradient values, in the range of 14–42°C/km, with the corresponding heat flow values falling in the range of 36–89 mW/m2. Maps of regional variations indicate that high heat flow anomaly in the São Francisco craton is limited to areas of sedimentary cover, to the west of the Espinhaço mountain belt. Crustal thermal models have been developed to examine the implications of the observed intracratonic variations in heat flow. The thermal models take into consideration variation of thermal conductivity with temperature as well as change of radiogenic heat generation with depth. Vertical distributions of seismic velocities were used in obtaining estimates of radiogenic heat production in crustal layers. Crustal temperatures are calculated based on a procedure that makes simultaneous use of the Kirchoff and Generalized Integral Transforms, providing thereby analytical solutions in 2D and 3D geometry. The results point to temperature variations of up to 300°C at the Moho depth, between the northern Salvador and southern São Francisco cratons. There are indications that differences in rheological properties, related to thermal field, are responsible for the contrasting styles of deformation patterns in the adjacent metamorphic fold belts.

Keywords

Heat flow Heat production São Francisco craton Thermal models 

Notes

Acknowledgments

The present work has been carried out as part of Ph.D. thesis work of the first author. We thank Dr. Iris Escobar for facilities provided for geothermal studies. Absence of financial support for Geothermal Laboratory of Observatório Nacional prevents us from thanking the funding organizations for scientific research in Brazil.

References

  1. Alexandrino CH, Hamza VM (2005a) Models for aquifers controlled by geologic faults with variable inclination (in Portuguese). In: Proceedings ninth international congress of the Brazilian geophysical society, Salvador, BrazilGoogle Scholar
  2. Alexandrino CH, Hamza VM (2005b) Geothermal gradients in the state of Minas Gerais (in Portuguese). In: Proceedings symposium on geology of the southeast Brazilian geological society, Niterói, Rio de JaneiroGoogle Scholar
  3. Alexandrino CH, Hamza VM (2006) Estimates of terrestrial heat flow and radiogenic heat generation in the southern part of the São Francisco Craton (in Portuguese). In: Proceedings second symposium of the Brazilian geophysical society, Natal, Brazil (Extended Abstract)Google Scholar
  4. Alkmin FF, Brito Neves BB, Alves JAC (1993) Tectonic framework of São Francisco Craton: a review (in Portuguese). In: Misi A, Dominguez ML (eds) The São Francisco Craton. Special Publication SBG, pp 45–62Google Scholar
  5. de Almeida FFM (1967) Origin and evolution of Brazilian platform (in Portuguese), Bulletin 241. DNPM/DGM, Rio de Janeiro, p 96Google Scholar
  6. de Almeida FFM (1969) Tectonic differentiation of the Brazilian Platform (in Portuguese). In: Proceedings, 23rd Brazilian geologic congress. Salvador, Brazil, pp 29–46Google Scholar
  7. de Almeida FFM (1977) The São Francisco Craton. Rev Bras Geoc 7:349–364Google Scholar
  8. de Almeida FFM, Amaral G, Cordani UG, Kawashita K (1973) The precambrian evolution of South America Cratonic Margin South of the Amazon River. In: Naim AE, Stehli FG (eds) The ocean basins and margins. New York Plenum Publ 1:411–446Google Scholar
  9. de Almeida FFM, Hasui Y, Neves BBB (1977) Brazilian structural provinces (in Portuguese). In: Proceedings 8° symposium on geology of northeast. Brazilian Geological Society, Campina Grande, pp 363–391Google Scholar
  10. Araújo RLC (1978) Terrestrial heat flow in the alkaline volcanic complex of Poços de Caldas. Unpublished M.Sc. Thesis, Observatório Nacional, Rio de Janeiro, BrazilGoogle Scholar
  11. Barbosa JSF (1990) The granulites of the Jequié complex and atlantic mobile belt, Southern Bahia, Brazil—an expression of archean proterozoic plate convergence. In: Vieklzuef D, Vidal PH (eds) Granulites and crustal evolution. Springer, Clermont-Ferrand, pp 195–221Google Scholar
  12. Barbosa JSF, Sabaté P, Marinho MM (2003) The São Francisco craton in Bahia: a synthesis (in Portuguese). Rev Bras Geoc 33:3–6Google Scholar
  13. Birch F, Clark H (1940) The thermal conductivity of rocks and its dependence upon temperature and composition. Am J Sci 238:529–558CrossRefGoogle Scholar
  14. Buntebarth G (1973) Model calculations on temperature-depth distribution in the area of the Alps and the foreland. Z Geophys 39:97–107Google Scholar
  15. Campos JEG, Dardenne MA (1997) Origin and Tectonic Evolution of the São Francisco Basin (in Portuguese). Rev Bras Geoc 27:283–294Google Scholar
  16. Cardoso RA, Hamza VM (2003) Geothermal gradients and heat flow in the continental platform of Southeast Brazil (in Portuguese). In: Proceedings 8th international congress of the Brazilian geophysical society. Rio de Janeiro, Brazil (Extended Abstract)Google Scholar
  17. Carslaw HS, Jaeger JC (1959) Conduction of heat in solids. Oxford University Press, New York, 386 ppGoogle Scholar
  18. Cermak V (1982) Crutsal temperature and mantle heat flow in Europe. Tectonophysics 83:123–142CrossRefGoogle Scholar
  19. Cermak V, Bodri L (1986) Temperature structure of the lithosphere based on 2D temperature modeling applied to Central and Eastern Europe. In: Burrus J (ed) Thermal modeling in sedimentary basins. Editions Technip, Paris, pp 7–32Google Scholar
  20. Cermak V, Bodri L (1993) Heat production in the continental crust, part I: data converted from seismic velocities and their attempted interpretation. Tectonophysics 225:15–28CrossRefGoogle Scholar
  21. Cermak V, Hurtig E (1979) Heat flow map of Europe, 1: 5,000,000. In: Cermak V, Rybach L (Eds) Terrestrial heat flow in Europe. Springer, Berlin (Enclosure)Google Scholar
  22. Cermak V, Bodri L, Rybach L (1991) Radioactive heat production in the continental crust and its depth dependence. In: Cermak V, Rybach L (eds) Terrestrial heat flow and the lithosphere structure. Springer, Berlin, pp 23–69Google Scholar
  23. Cordani UG (1973) Definition and characterization of São Francisco Craton: discussion. In: Proceedings, 27th Brazilian geological congress, vol 2, Aracaju, pp 147–148Google Scholar
  24. Cordani UG, Melcher GC, Almeida FFM de (1968) Outline of Precambrian geochronology of South America. Can J Earth Sci 5:624–632Google Scholar
  25. Cordani UG, Amaral G, Kawashita K (1973) The precambrian evolution of South America. Geol Rundschau 62:309–317CrossRefGoogle Scholar
  26. Cotta RM (1993) Integral transforms in computational heat and fluid flow. CRC Press, Boca RatonGoogle Scholar
  27. Del Rey AC, Zembruscki SG (1991) Hydrothermic study of the Espirito Santo and Mucuri basins. Bol Geociências PETROBRÁS 5:25–38Google Scholar
  28. Ferreira LET (2003) Assessment of geothermal resources of the state of Goiás (in Portuguese), Unpublished M.Sc. Thesis, Observatório Nacional, Rio de Janeiro, BrazilGoogle Scholar
  29. Ferreira LET, Hamza VM (2005) Random simulation with geologic control in assessment of geothermal resources of the state of Goiás, Central Brazil. In: Proceedings World Geothermal Congress, Antalya, TurkeyGoogle Scholar
  30. Ferreira C, Barreto PT, Torquato JF (1979) Reconhecimento gamametrico da região central da Bahia e da Bacia do Reconcavo. Rev Bras Geoc 9:249–265Google Scholar
  31. Ferreira C, Moreira-Nordemann LM, Nordemann DJR (1992) A radioatividade natural da região de Irecê. Bahia Rev Bras Geoc 22:167–174Google Scholar
  32. Gasparini P, Mantovani MSM (1979) Geochemistry of charnockites from São Paulo state, Brazil. Earth Planet Sci Lett 42:311–320CrossRefGoogle Scholar
  33. Golden Software Inc. (2002) SURFER Version 8, Surface Mapping System. Golden Software Inc., USAGoogle Scholar
  34. Gomes AJL (2004) Assessment of geothermal resources of the state of Rio de Janeiro, Unpublished M.Sc. Thesis, Observatório Nacional, Rio de Janeiro, BrazilGoogle Scholar
  35. Gomes AJL, Hamza VM (2003) Assessment of Geothermal resources of the state of Rio de Janeiro (in Portuguese). 8° International Congress of the Brazilian Geophysical Society, Rio de JaneiroGoogle Scholar
  36. Gomes AJL, Hamza VM (2005) Geothermal gradients and heat flow in the state of Rio de Janeiro. Braz J Geophys 23:325–347Google Scholar
  37. Hamza VM (1980) Estimates of terrestrial heat flow and radiogenic heat production in Eastern Brazil. Proce XXXI Braz Geol Cong 2:1149–1160Google Scholar
  38. Hamza VM (1982) Thermal structure structure of South American Continental Lithosphere during Archean and Proterozoic. Rev Bras Geoc 12:149–159Google Scholar
  39. Hamza VM, Beck AE (1972) Terrestrial heat flow, the Neutrino problem, and a possible energy source in the core. Nature 240:343–344CrossRefGoogle Scholar
  40. Hamza VM, Eston SM (1983) Assessment of geothermal resources of Brazil-1981. Zbl Geol Palaontol I:128–155Google Scholar
  41. Hamza VM, Muñoz M (1996) Heat flow map of South America. Geothermics 25:599–646CrossRefGoogle Scholar
  42. Hamza VM, Silva Dias FJS (2003) Functional representation of regional heat flow in South America: Implications for the occurrence of low-temperature geothermal resources. Geotherm Resour Council Trans 27:615–618Google Scholar
  43. Hamza VM, Eston SM, Araujo RLC, Vitorello I, Ussami N (1978a) Brazilian geothermal data collection series-1, Instituto de Pesquisas Tecnológicas do Estado de São Paulo, IPT, Publication No. 1109Google Scholar
  44. Hamza VM, Eston SM, Araújo RLC (1978b) Geothermal energy prospects in Brazil. Pure Appl Geophys 117:180–195CrossRefGoogle Scholar
  45. Hamza VM, Silva Dias FJS, Gomes AJL, Terceros ZD (2005) Numerical and functional representation of regional heat flow in South America. Phys Earth Planet Interiors 152:223–256Google Scholar
  46. Institute of Mathematical and Statistical Library (IMSL) (1989) Math/Lib. Houston, TexasGoogle Scholar
  47. Iyer SS, Choudhuri A, Vasconsellos MBA, Cordani UG (1984) Radioactive element distribution in the Archean granulite terrain of Jequié, Bahia, Brazil. Contrib Mineral Petrol 85:95–101CrossRefGoogle Scholar
  48. Lachenbruch AH (1970) Crustal temperature and heat production: implication of the linear heat flow relation. J Geophys Res 71:1224–1248Google Scholar
  49. Marangoni YR (1986) A comparative study of the methods of measuring thermal conductivity of geological materials (in Portuguese). Unpublished M.Sc. Thesis, University of São Paulo, São Paulo, Brazil, 134 ppGoogle Scholar
  50. Özisik MN (1980) Heat conduction. Wiley, New York, pp 687Google Scholar
  51. Pacheco RP (2003) Three dimensional S wave imaging of the Lithosphere of Southeast Brazil and adjacent areas (in Portuguese), Unpublished Ph.D. Thesis, Observatório Nacional, Rio de Janeiro, Brazil, pp 470Google Scholar
  52. Pflug R, Schabenhaus C, Renger F (1969) Contribution to geotectonics of Eastern Brazil (in Portuguese). Special Publication SUDENE, Recife, pp 55Google Scholar
  53. Ribeiro FB (1987) A study of the problem of determining equilibrium temperatures in wells (in Portuguese). Unpublished Ph.D. Thesis, University of São Paulo, São Paulo, Brazil, 176 ppGoogle Scholar
  54. Roque A, Ribeiro FB (1997) Radioactivity and radiogenic heat production in the sediments of the São Francisco sedimentary basin. Central Brazil Appl Radiat Isot 48:413–422CrossRefGoogle Scholar
  55. Sapucaia NC, Max de Argollo R, Barbosa JSF (2005) Teores de Potássio, Urânio, Tório e Taxa de produção de calor radiogênico no embasamento adjacente ás bacias sedimentares de Camamu e Almada, Bahia, Brasil. Braz J Geophys 23:453–476Google Scholar
  56. Sekiguchi K (1984) A method for determining terrestrial heat flow in oil basinal areas. Tectonophysics 103:67–79CrossRefGoogle Scholar
  57. Sighinolfi GP, Sakai T (1977) Uranium and Thorium in Archean granulite facies terrain of Bahia (Brazil). Geochem J 11:33–39Google Scholar
  58. Silva GBD (2006) Curie surface in the Southern Bahia Region—Spectral analysis over high resolution aeromagnetic data (in Portuguese). Unpublished M.Sc. Thesis, Observatório Nacional, Rio de Janeiro, pp 145Google Scholar
  59. Trompette RR, Uhlein A, Silva ME, Karmann I (1992) The Brazilian Craton of São Francisco—a review (in Portuguese). Rev Bras Geoc 22:481–486Google Scholar
  60. Ussami N (1993) Geophysical studies in São Francisco Craton: present stage and perspectives (in Portuguese). In: Dominguez JML, Misi A (eds) Symposium Craton São Francisco 2. Special Publication, Salvador, pp 35–62Google Scholar
  61. Verdoya M, Pasquale V, Chiozzi P, Kukkonen IT (1998) Radiogenic heat production in the Variscan crust: new determinations and distribution models in Corsica (northwestern Mediterranean). Tectonophysics 291: 63–75CrossRefGoogle Scholar
  62. Vitorello I, Hamza VM, Pollack HN (1980) Terrestrial heat flow in the Brazilian highlands. J Geophys Res 85:3778–3788CrossRefGoogle Scholar
  63. Wessel P, Smith WHF (1998) New, improved version of generic mapping tools released. EOS Trans Am Geophys 79(47):579CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Observatório NacionalRio de JaneiroBrazil

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