Origin of Gold from the Golfo Dulce Placer Province, Southern Costa Rica

  • Jevan P. Berrangé
Part of the Circum-Pacific Council for Energy and Mineral Resources Earth Science Series book series (CIRCUM-PACIFIC, volume 16)


The Golfo Dulce goldfield has been mined since pre-Columbian times and currently produces at least twice as much gold as the entire Tilarán-Aguacate Gold Province in northern Costa Rica. The gold is mainly concentrated in eluvial, colluvial, and alluvial placers in the Osa Group (late Pliocene) and the Puerto Jiménez Group (late Pleistocene-Holocene) that unconformably overlie the Nicoya Complex basement (Late Cretaceous-early Tertiary). This is a segment of oceanic crust characterized by EMORB-type basalts typical of a back arc basin such as the Mariana Trough.

Studies of the geographic and stratigraphic distribution of the placer gold, its habit and composition, and the associated heavy mineral suite, demonstrate conclusively that it was locally derived from the nearby Nicoya Complex. The gold was initially concentrated in epithermal auriferous quartz lodes in the basalts, and in interlayered pelagic sediments, by hot circulating fluids (seawater and magmatic fluids) related to one or more of three submarine volcanic events. Translative plate movement and subsequent obduction and isostatic uplift of this segment of oceanic crust during development of the Southern Central America Orogen allowed weathering and erosion of the ophiolite complex. This produced native gold and gold in solution that was concentrated during several cycles as placers in the associated sediments.

The primary gold deposits of the Southern Central America Orogen, in Costa Rica and Panamá, appear to include two distinct types and occur as (1) epithermal Au−Ag+(P−Zn−Cu) deposits of late Tertiary age associated with calc-alkaline acid-intermediate intrusives and/or volcanics in the inner arc, or (2) as epithermal low-Ag deposits in ophiolite terrains of the outer arc. These probably originated by hydrothermal activity related to submarine basaltic volcanism in an extensional environment such as aback arc basin, and are significantly older—Late Cretaceous to early Tertiary. The Golfo Dulce goldfield is the most westerly occurrence of an “ophiolite gold province.” The recognition that virtually uncratonized oceanic crust in this region forms the “source beds” for gold deposits suggests that similar ophiolitic terrains in the eke urn-Pacific and Caribbean should be regarded as gold exploration targets.


Gold Deposit Oceanic Crust Versus Versus Versus Versus Versus Versus Versus Versus Versus British Geological Survey 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Anonymous (Republica de Costa Rica and Organización de los Estados Americanos), 1978, Diagnóstico del Sector Minero: San José, Imprenta Nacional, 91 p.Google Scholar
  2. Azuola, H., 1985, Occurrences and origin of heavy mineral placers in braided stream facies of the Agujas River, Osa Peninsula, CostaRica: Pennsylvania State University, Department of Geo-sciences, M.Sc. Thesis, 164 p.Google Scholar
  3. Barritt, S., and J. P. Berrangé, 1987, An interpretation of a gravity survey of the Osa Peninsula and environs, southern Costa Rica: Overseas Geology and Mineral Resources, no. 64, 18 p.Google Scholar
  4. Berrangé, J. P., 1987, Goldin Costa Rica: Mining Magazine (May), p. 402–407.Google Scholar
  5. Berrangé, J. P., 1988, Geological maps of the Osa Peninsula: sheets Sierpe, Rincón, Llorona, Golfo Dulce, Madrigal and Carate, scale 1:100,000, includes explanatory notes in English and Spanish: British Geological Survey, Overseas Directorate, unpublished colored photocopies.Google Scholar
  6. Berrangé, J. P., 1990, The Osa Group: An auriferous Pliocene sedimentary unit from the Osa Peninsula, southern Costa Rica: Revista Geologica de América Central, no. 10, p. 67–93.Google Scholar
  7. Berrangé, J. P., in preparation, Gold from the Golfo Dulce Placer Province, southern Costa Rica.Google Scholar
  8. Berrangé, J. P., and R. S. Thorpe, 1988, The geology, geochemistry and emplacement of the Cretaceous/Tertiary ophiolitic Nicoya Complex of the Osa Peninsula, southern Costa Rica: Tectonophysics, v. 147, p. 193–220.Google Scholar
  9. Berrangé, J. P., D. R. Bradley, and N. J. Snelling, 1989, K:Ar age dating of the ophiolitic Nicoya Complex of the Osa Peninsula, southern Costa Rica: Journal of South American Earth Sciences, v. 2, no. 1, p. 49–59.Google Scholar
  10. Boyle, R. W., 1979, The geochemistry of gold and its deposits: Geological Survey of Canada, Bulletin 280, 584p.Google Scholar
  11. Buisson, G., and M. Leblanc, 1986, Gold-bearing listwaenites (carbonatizedultramafic rocks) from ophiolite complexes, in M. J. Gallagher, R. A. Ixer, C. R. Neary, and H. M. Prichard, eds., Proceedings of the conference: Metallogeny of basic and ultra-basic rocks, Edinburgh, Scotland, 9–12 April 1985: Institution of Mining and Metallurgy, p. 121–131.Google Scholar
  12. Dengo, G., 1985, Mid America: Tectonic setting for the Pacific margin from southern Mexico to northwestern Colombia, in A. E. M. Nairn, F. G. Stehli, and S. Uyeda, The ocean basins and margins, v. 7A, The Pacific Ocean: New York: Plenum Press, p. 123–180.Google Scholar
  13. Gross, G. A., 1987, Mineral deposits on the deep seabed: Marine Mining, v. 6, p. 109–119.Google Scholar
  14. Gross, G. A., and C. R. McLeod, 1987, Metallic minerals on the deep seabed: Geological Survey of Canada, Paper 86–21, 65p.Google Scholar
  15. Gross, G. A., and C. R. McLeod, 1987, Metallic minerals on the deep seabed: Geological Survey of Canada, Paper 86–21, 65p.Google Scholar
  16. Kesler, S. E., 1978, Metallogenesis of the Caribbean region: Journal Geological Society of London, v. 135, p. 429–441.Google Scholar
  17. Levy, E., 1970, La metalogenesis en America Central: Instituto Centroamericano de Investigación y Tecnologia Industrial (ICAITI), Publicaciones Geológicas del ICAITI, no. 3, p. 17–57.Google Scholar
  18. Lew, L. R., 1983, The geology of the Osa Peninsula, Costa Rica: Observations and speculations about the evolution of part of the outer arc of the Southern Central American Orogen: Pennsylvania State University, Department of Geosciences, M.Sc. Thesis, 128 p.Google Scholar
  19. U.S. Geological Survey, Dirección General de Geologia e Hidrocarburos, and Universidad de Costa Rica, 1987, Mineral resource assessment of the Republic of Costa Rica: U.S. Geological Survey Miscellaneous Investigations Series Map I - 1865.Google Scholar
  20. Weyl, R., 1980, Geology of Central America: Berlin, Gebrüder Borntraeger, 371 p.Google Scholar

Copyright information

© Circum-Pacific Council for Energy and Mineral Resources 1995

Authors and Affiliations

  • Jevan P. Berrangé
    • 1
  1. 1.Overseas DirectorateBritish Geological SurveyKeyworth, NottinghamshireUK

Personalised recommendations