Geophysical Investigation of Magnetometry in Zarnan-Chorenab Zanjan Menitite Iron Deposit

Document Type : Research - Paper

Authors

1 M.Sc Student, School of Geology, College of Science, University of Tehran, Tehran, Iran

2 Associate Professor, School of Geology, College of Science, University of Tehran, Tehran, Iran

3 M.Sc, Ahura Holding Industrial-Mining Group, Tehran, Iran

4 Assistant Professor, School of Geology, College of Science, University of Tehran, Tehran, Iran

Abstract

Zarnan-Chorehnab iron deposits are located at 5 km northeast of Zanjan city in the Tarom mountains, between Zarnan and Chorehnab villages. Mineralogical studies, as well as field observations show that iron mineralization is mostly magnetite type. However, hematite and goethite minerals are also formed to a lesser extent due to weathering and alteration. Iron ores in this area are formed as veins and lenses within Oligocene intrusive bodies. Inside the volcanic rocks, mineralization is also observed in the form of veins with small dimensions. The thickness of the veins can be traced between 0.5 to about 15 meters and their length up to about 200 meters. Iron deposits are one of the main stages of their exploration due to the presence of magnetite minerals with high magnetic properties and hematite with low magnetic properties. For this purpose, geophysical surveys were carried out by magnetometric method in 5240 stations in an area of 8 km2 to determine the potential areas of iron mineralization and to investigate the depth of mineralization. In this research, total magnetic maps, pole reversal, analytical signal, and upward continuation were prepared. The results obtained from the drilling finely correspond with the magnetometric survey. Based on the results of these studies, nine anomalies (An1-An9) were identified in the study area, anomalies of An3, An8, and An9 extend to a depth of about 40 m, and other anomalies are supposed to be found to a greater depth. The result of magnetic modeling data determines the position (location and approximate depth) and geometry of the masses causing magnetic anomalies.

Keywords

Main Subjects

References

  1. Donohue, J., Hil, Q., and Brewster, D. (2012). “Geophysics at the Howsons Iron Project, NSW, Eastern Australia’s new magnetite resource”. ASEG Extended Abstracts, 1-6.
  2. رابینسون، ای. اس.، کیت، ک.؛ ترجمه حیدریان شهری، م. ر.؛ 1384؛ "مبانی اکتشافات ژئوفیزیک". دانشگاه فردوسی مشهد.
  3. Ganiyu, S. A., Badmus, B. S., Awoyemi, M. O., Akinyemi, O. D., and Olurin, O. T. (2012). “Upward continuation and reduction to pole process on aeromagnetic data of Ibadan Area, South-Western Nigeria”. Earth Science Research, 2(1): 66.
  4. Spicer, B., Morris, B., and Ugalde, H. (2011). “Structure of the Rambler Rhyolite, Baie Verte Peninsula, Newfoundland: Inversions using UBC-GIF Grav3D and Mag3D”. Journal of Applied Geophysics, 75: 9-18.
  5. کلاگری، ع. ا.؛ 1384؛ "اصول اکتشافات ژئوفیزیکی". دانشگاه تبریز.
  6. Telford, W. M., Geldart, L. P., Sheriff, R. E., and Keys., D. A. (1988). “Applied geophysics”. Cambridge University Press.  
  7. Baranov, V., and Naudy, H. (1964). “Numerical calculation of the formula of reduction to the magnetic pole”. Geophysics, 29: 67-79.
  8. Jacobsen, B. H. (1987). “A case for upward continuation as a standard separation filter for potential-field maps”. Geophysics, 52: 1138-1148.
  9. Liu, S., and Mackey, T. (1998). “Using images in a geological interpretation of magnetic data. Australian”. Geological Survey Organisation Research Newsletter, 28: 1-3.
  10. Clark, D. A. (1997). “Magnetic petrophysics and magnetic petrology: aids to geological interpretation of magnetic surveys”. Journal of Australian Geology and Geophysics, 17(2): 83-103.
  11. Nakatsuka, T., and Okuma S. (2006). “Reduction of magnetic anomaly observations from helicopter surveys at varying elevations”. Exploration Geophysics, 37(1): 121-128.
  12. Guun, P. J., Madment, D., and Miligan, P. R. (1997). “Interpretation of aeromagnetic data in area of limited outcrop”. Journal of Australian Geology and Geophysics (AGSO), 17(2): 175-185.
  13. Mansouri, E., Feizi, F., and Karbalaei Ramezanali, A. (2015). “Identification of magnetic anomalies based on ground magnetic data analysis using multifractal modelling: a case study in Qoja Kandi, East Azerbaijan Province, Iran”. Nonlinear Processes Geophysics, 22: 579-587.
  14. Cooper, G. R. J., and Cowan, D. R. (2008). “Edge enhancement of potentialfield data using normalize statistics”. Geophysics, 73(3): H1-H4.
  15. Smith, R. S., Salem, A., and Lemieux, J. (2005). “An enhanced method for source parameterimaging of magnetic data collected or mineral exploration”. Geophysical Prospecting, 53: 655-665.
  16. Blakely, R. (1995). “Potential theory in gravity and magnetic applications”. Cambridge University Press.
  17. Henderson, R. G., and Zietz, I. (1949). “The upward continuation of anomalies in total magnetic intensity fields”. Presented at St. Louis Meeting of the Society, U. S. Geological Survey.
  18. Tarlowski, C., Gunn, P. J., and Mackey, T. (1997). “Enhancements of the magnetic map of Australia”. Journal of Australia Geology and Geophysics, 17(2): 77-82.
  19. Peters, L. J. (1949). “The direct approach to magnetic interpretation and its practical application”. Geophysics, 14(3): 290-320.
  20. Hartman, R. R., Teskey, D. J., and Friedberg, J. L. (1971). “A system for rapid digital aeromagnetic interpretation”. Geophysics, 36: 891-918.
  21. Thompson, D. (1982). “EULDPH -A new technique for making computer-assisted depth estimates from magnetic data”. Geophysics, 47: 31-37.
  22. Reid, A. B., Allsopt, J. M., Granser, H., Milletts, A. J., and Somerton, I. W. (1990). “Magnetic interpretation in three dimensions using Euler deconvolution”. Geophysics, 55: 80-91.
  23. Barbosa, V. C. F., Silva, J. B. C., and Medeiros, W. E. (1999). “Stability Analysis and improvement of structural index estimation in Euler deconvolution”. Geophysics, 64: 48-60.
  24. Hansen, D. T., and Suciu, L. (2002). “Multiple source Euler deconvolution”. Geophysics, 67: 525-535.
  25. FitzGerald, D., Reid, A., and McInerney, P. (2004). “New discrimination techniques for Euler deconvolution”. Computers and Geoscience, 30: 461 469.
  26. Cooper, G. R. J., and Cowon, D. R. (2006). “Enhancing potential field data using filters based on the local phase”. Computers & Geoscience, 32(10): 1585-1591.
  27. Quesnel, Y., Langlais, B., Sotin, C., and Gald eano, A. (2008). “Modelling and inversion of local magnetic anomalies”. Journal of Geophysical Engineering, 5: 387-400.
  28.  Nabighian, M. N. (1972). “The analytic signal of two-dimensional magnetic bodies with polygonal cross-section”. Its properties and use for automated anomaly interpretation: Geophysics, 37: 507-517.
  29. حسین زاده گویا، ن.؛ 1387؛ "تئوری پتانسیل در گرانی و مغناطیس کاربردی". انتشارات دانشگاه تهران.
Journal of Mineral Resources Engineering
Volume 7, Issue 4 - Serial Number 26
December 2022
Pages 19-38

Files

History

  • Receive Date: 19 June 2021
  • Revise Date: 29 December 2021
  • Accept Date: 13 October 2021

Share

How to cite

Statistics