1887
24th International Geophysical Conference and Exhibition – Geophysics and Geology Together for Discovery
  • ISSN: 2202-0586
  • E-ISSN:

Abstract

Porphyry ore deposits are well known to be associated with arc magmatism related to subduction on the overriding plate. Furthermore, the regional mechanisms for magmatism and the resulting formations of porphyry deposits are well established. Specific parameters leading to these events have been inferred, but not formally tested. We aim to identify the specific set of tectono-magmatic parameters that result in a subducting slab producing particular types of magmatism on the overriding plate, and their link to the formation of ore deposits. We use a four-dimensional approach to reconstruct age-dated magmatism back through space and time to isolate the tectono-magmagic parameters leading to the formation of a metalliferous deposit during subduction. By utilising machine learning techniques we identify and quantify geodynamic parameters that are robust predictors of back-arc magmatism and porphyry formation. The ‘random-forest’ ensemble and ‘support vector machines’ learning classification methods are employed to prioritise parameters that are considered influential in the development of magmatism and the subsequent metallogenesis of porphyry ore deposits. We find that a combination of convergence rates and directions, seafloor age, subduction obliquity, and the distance to a trench edge help predict whether magmatism and related ore deposits occur.

Loading

Article metrics loading...

/content/journals/10.1071/ASEG2015ab278
2015-12-01
2026-01-24
Loading full text...

Full text loading...

References

  1. Bertrand, G., Guillou-Frottier, L. & Loiselet, C. (2014), ‘Distribution of porphyry copper deposits along the western tethyan and andean subduc- tion zones: Insights from a paleotectonic approach’, Ore Geology Reviews 60(0), 174 -190.
  2. Brieman, L. (2001), ‘Random Forests’, Machine Learning 45(1), 5-32.
  3. Capitanio, F. A., Faccenna, C., Zlotnik, S. & Stegman, D. R. (2011), ‘Subduction dynamics and the origin of andean orogeny and the bolivian orocline’, Nature 480(7375), 83-86.
  4. Cortes, C., Vapnik, V. (1995), ‘Support Vector Networks’, Machine Learning 20(3), 273-297.
  5. Cracknell, M. J. & Reading, A. M. (2014), ‘Geological mapping using remote sensing data: A comparison of five machine learning algorithms, their response to variations in the spatial distribution of training data and the use of explicit spatial information’, Computers & Geosciences 63(0), 22-33.
  6. Griffin, W. L., Begg, G. C. & O’Reilly, S. Y. (2013), ‘Continental-root control on the genesis of magmatic ore deposits’, Nature Geoscience 6(11), 905-910.
  7. Jarrard, R. D. (1986), ‘Relations among subduction parameters’, Reviews of Geophysics 24(2), 217-284.
  8. Jingwen, M., Yanbo, C., Maohong, C. & Pirajno, F. (2013), ‘Major types and time-space distribution of mesozoic ore deposits in south china and their geodynamic settings’, 48(3), 267-294.
  9. Khomich, V. G., Boriskina, N. G. & Santosh, M. (2014), ‘A geodynamic perspective of world-class gold deposits in east asia’, Gondwana Research (0).
  10. Macpherson, C. G. & Hall, R. (2002), ‘Timing and tectonic controls in the evolving orogen of se asia and the western pacific and some implications for ore generation’, Geological Society, London, Special Publications 204(1), 49-67.
  11. Maloney, K. T., Clarke, G. L., Klepeis, K. A. & Quevedo, L. (2013), ‘The late jurassic to present evolution of the andean margin: Drivers and the geological record’, Tectonics 32(5), 1049-1065.
  12. Ramos, V. A. (2010), ‘The tectonic regime along the andes: Present-day and mesozoic regimes’, Geological Journal 45(1), 2-25.
  13. Richards, J. P. (2003), ‘Tectono-magmatic precursors for porphyry cu-(mo-au) deposit formation’, Economic Geology 98(8), 1515-1533.
  14. Richards, J. P. (2013), ‘Giant ore deposits formed by optimal alignments and combinations of geological processes’, Nature Geosci 6(11), 911-916.
  15. Rosenbaum, G., Giles, D., Saxon, M., Betts, P., Weinberg, R. & Duboz, C. (2005), ‘Subduction of the nazca ridge and the inca plateau: Insights into the formation of ore deposits in peru’, Earth and Planetary Science Letters 239(1 -2), 18-32.
  16. Schellart, W. P. (2008), ‘Overriding plate shortening and extension above subduction zones: A parametric study to explain formation of the andes mountains’, Geological Society of America Bulletin 120(11-12), 1441.
  17. Schodde, R. (2011), Recent trends in gold discovery, in ‘Keynote address to the NewGenGold Conference, Perth, November’.
  18. Seton, M., Mu ller, R., Zahirovic, S., Gaina, C., Torsvik, T., Shephard, G., Talsma, A., Gurnis, M., Turner, M., Maus, S. & Chandler, M. (2012), ‘Global continental and ocean basin reconstructions since 200 ma’, Earth-Science Reviews 113,
  19. 212-270.
  20. Shatwell, D. (2004), Subducted ridges, magmas, differential uplift and gold deposits: Examples from south and central america, in ‘The Ishihara Symposium: Granites and Associated Metallogenesis, Geoscience, Australia’, pp. 115-120.
  21. Shephard, G. E., Mu ller, R. D. & Seton, M. (2013), ‘The tectonic evolution of the arctic since pangea breakup: Integrating constraints from surface geology and geophysics with mantle structure’, Earth-Science Reviews 124(0), 148183.
  22. Thi’eblemont, D., Stein, G. & Lescuyer, J.-L. (1997), ‘Gisements epithermau et porphyri ues: la conne ion adakite’, Comptes Rendus de l’Acad emie des Sciences -Series IIA - Earth and Planetary Science 325(2), 103-109.
/content/journals/10.1071/ASEG2015ab278
Loading
  • Article Type: Research Article
Keyword(s): Machine Learning; Plate kinematics; Porphyry; South America
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error