Application of Forward and Inverse Modelling to High-Resolution Gravity Data for Mineral Exploration

نوع مقاله : مقاله پژوهشی

نویسندگان

1 Senior Lecturer, Department of Physics, College of Physical Sciences, Federal University of Agriculture, Abeokuta, Nigeria

2 M.Sc. Student, Department of Physics, College of Physical Sciences, Federal University of Agriculture, Abeokuta, Nigeria

3 Professor, Department of Physics, College of Physical Sciences, Federal University of Agriculture, Abeokuta, Nigeria

چکیده

Gravity survey is a geophysical tool used to investigate the subsurface by measuring the differences in Earth’s gravitational field. The high-resolution gravity data within latitude 70.00׀ - 70.30 ׀N, and longitude 30.00 ׀- 30.30 ׀E was acquired through Bureau Gravimetrique Internationale (EGM2008). The research work employed the methods of the filtering techniques as well as forward and inverse modelling for data analysis and interpretations. The qualitative results of the gravity anomaly of the field through the regional-residual separation technique and the high pass filters show the local and geologic features of the study area. The low, fairly high and high-density areas are characterized by alluvial, meta-sediments/sedimentary and igneous deposits respectively. The derivative maps aided the locations, boundaries and edges of anomalous bodies, including the transition zones and sedimentary intrusions of the study area. Forward and inverse modeling techniques were applied to profiles (P1-P4) in a quantitative approach, to describe the geometry, density contrast, depth, position, strike, dip and plunge. The depth range of 1268 m to 3111 m was calculated, while the density contrasts of gravity bodies suggest the presence of mineral rocks such as limestone, quartz, gneiss, sandstone, schist, granite, quartzite and gypsum.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Application of Forward and Inverse Modelling to High-Resolution Gravity Data for Mineral Exploration

نویسندگان [English]

  • Gideon O, Layade 1
  • Hazeez O. Edunjobi 2
  • Victor Makinde 3
  • B. Saheed Bada 1
1 Senior Lecturer, Department of Physics, College of Physical Sciences, Federal University of Agriculture, Abeokuta, Nigeria
2 M.Sc. Student, Department of Physics, College of Physical Sciences, Federal University of Agriculture, Abeokuta, Nigeria
3 Professor, Department of Physics, College of Physical Sciences, Federal University of Agriculture, Abeokuta, Nigeria
چکیده [English]

Gravity survey is a geophysical tool used to investigate the subsurface by measuring the differences in Earth’s gravitational field. The high-resolution gravity data within latitude 70.00׀ - 70.30 ׀N, and longitude 30.00 ׀- 30.30 ׀E was acquired through Bureau Gravimetrique Internationale (EGM2008). The research work employed the methods of the filtering techniques as well as forward and inverse modelling for data analysis and interpretations. The qualitative results of the gravity anomaly of the field through the regional-residual separation technique and the high pass filters show the local and geologic features of the study area. The low, fairly high and high-density areas are characterized by alluvial, meta-sediments/sedimentary and igneous deposits respectively. The derivative maps aided the locations, boundaries and edges of anomalous bodies, including the transition zones and sedimentary intrusions of the study area. Forward and inverse modeling techniques were applied to profiles (P1-P4) in a quantitative approach, to describe the geometry, density contrast, depth, position, strike, dip and plunge. The depth range of 1268 m to 3111 m was calculated, while the density contrasts of gravity bodies suggest the presence of mineral rocks such as limestone, quartz, gneiss, sandstone, schist, granite, quartzite and gypsum.

کلیدواژه‌ها [English]

  • Gravity
  • Density
  • Filtering
  • High-resolution
  • Modelling
  • Depth

مراجع

Adegoke, J. A. and Layade, G. O., 2019, Comparative depth estimation of iron-ore deposit using the Data-Coordinate Interpolation Technique for airborne and ground magnetic survey variation, African Journal of Science, Technology, Innovation and Development. 11(5), 663-669, doi: 10.1080/20421338.2019. 1572702.
Akinse, A.G. and Gbadebo, A.M., 2016, Geological mapping of Abeokuta Metropolis, Southwestern Nigeria. International Journal of Scientific & Engineering Research, 7(8), 979-983.
Badmus, B.S., Olurin, O.T., Ganiyu and, S.A. and Oduleye, O.T., 2013, Evaluation of Physical        Parameters of Various Solid Minerals within Southwestern Nigeria using Direct   Experimental Laboratory Methods. American International Journal of Contemporary       Research, 3(3), 152-161.
Barnes, G. J., Lumley, J. M., Houghton P. and Gleave, R., 2011, Comparing gravity and gravity gradient surveys: Geophysical Prospecting, 59, 176–187, doi:10.1111/j.1365-2478.2010.00900.x.
Bello, R. and Falano, O.C., 2017, Interpretation of Aeromagnetic Anomalies over Abeokuta, Southwest Nigeria, using Spectral Depth Technique. Journal of Applied Sciences in Environmental Management, 21(2), 218-222.
Blakely, R. J., 1995, Potential theory in gravity and magnetic applications: Cambridge University Press. ISBN: 9780511549816; DOI: 10.1017/CBO9780511549816.
Dransfield, M. H. and Zeng, Y., 2009, Airborne gravity gradiometry: Terrain corrections and elevation error. Geophysics, 74, I37-I42.
Foulger, G.R., Du, Z. and Julian, B.R., 2013, Icelandic Type Crust, Geophysical Journal International, 155, 567-590.
Hammer, S., 1939, Terrain corrections for gravimeter stations: Geophysics, 4, 184–194, doi:10.1190/1.1440495.
Zahra, H.S. and Hesham, T.O., 2016, Application of High-Pass Filtering Techniques on Gravity and Magnetic Data of the Eastern Qattara Depression Area, Western Desert, Egypt. National Research Institute of Astronomy and Geophysics, 5, 106-123.
Houghton, P., Bate, D., Davies, M. and Lumley, J., 2007, Using gravity gradiometry as a blueprint for exploration in thrust and fold belts: First Break, 25, 105–112.
Keary, P. and Brooks, I., 1984, Introduction to Geophysical Exploration. Blackwell Scientific Publishers, in: Pure Appl. Geophys, 123(1985), 171–172.
Jones, H.A. and Hockey, R.O., 1964, The Geology of Parts of Southwestern Nigeria. Bull. Geol. Surv. Nigeria 31, 101 – 102.
Mendonca, C. A. and Silva, B. C., 1995, Interpolation of potential-field data by equivalent layer and minimum curvature: A comparative analysis: Geophysics, 60, 399–407, doi:10.1190/1.1443776.
Nicolas, O.M., 2009, The Gravity Method. Exploration for Geothermal Resources, 1-9.
Obaje, N.G., 2009, Geology and mineral resources of Nigeria. Lecture Note in Earth Science Series, Vol. 120.
Onyishi, G.E., Ugwu, G.Z. and Okonkwo, A., 2019, Forward and Inverse Modelling of Aeromagnetic Anomalies over Parts of Middle Benue Trough, Nigeria. American Journal of Geophysics, Geochemistry and Geosystems, 5(1) 16-23.
Olowofela, J.A., Akinyemi, O.D., Badmus, B.S., Awoyemi, M.O., Olurin, O.T. and Ganiyu, S.A., 2013, Depth estimation and source location of Magnetic anomalies from a Basement Complex Formation, using Local Wavenumber Method (LWM). IOSR Journal of Applied Physics, 4(2), 33-38.
Olurin, O.T., Olowofela, J.A., Akinyemi, O.D., Badmus, B.S., Idowu, O.A. and Ganiyu, S.A., 2015, Enhancement and Basement Depth Estimation from Airborne Magnetic Data. African Review of Physics, 10(38), 303-313.
Pajot, G., de Viron, O., Diament, M., Lequentrec-Lalancette, M.F. and Mikhailov, V., 2008, Noise reduction through joint processing of gravity and gravity gradient data: Geophysics, 73(3), I23–I34, doi:10.1190/ 1.2905222.
Rahaman, M.A., 1976, Review of the basement geology of south western Nigeria in Geology of Nigeria edited by C. A Kogbe. Elizabethan publishing company, Lagos; 41-58.
Revees, C., 2005, Aeromagnetic Surveys; Principles, Practice and Interpretation. GEOSOFT, 155.
Reynolds, M.J., 1997, Introduction to applied and environmental geophysics. John Wiley and Sons, New York USA. 796 p.
Telford, W. M., Geldart, L. P., Sheriff, R. E. and Keys, D. A., 1976, Applied Geophysics: Cambridge University Press. xvii + 860 pp.
Telford, W.M., Geldart, L.P. and Sheriff, R.E., 1990, Applied geophysics (2nd edition), Cambridge University Press, Cambridge, 770.
While, J., Biegert, E. and Jackson, A., 2008, Interpolation of gravity and gravity gradient data by using the generalized sampling expansion: Theory: Geophysics, 73(2), I11–I21, doi:10.1190/1.2831934.
فیزیک زمین و فضا
دوره 46، شماره 4
بهمن 1399
صفحه 117-129

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