Predicting Depth of Mineral Deposit using Gravity-Density Downward Correlation by Fourier Transform

Authors

  • E. E. Epuh Department of Surveying and Geoinformatics, University of Lagos, Nigeria
  • J. B. Olaleye Department of Surveying and Geoinformatics, University of Lagos, Nigeria
  • O. G. Omogunloye Department of Surveying and Geoinformatics, University of Lagos, Nigeria

DOI:

https://doi.org/10.24028/gzh.0203-3100.v38i5.2016.107827

Keywords:

isostatic residual gravity anomaly, downward continuation, density log, attenuation, weighting density function

Abstract

Residual gravity anomalies are the superposition of effects originating from several interfaces in the subsurface. In downward projection of the anomalies for the determination of the depth of the particular substructure which accounts for the bulk of the residual gravity anomalies on the plane can only be resolved with the aid of additional subsurface data such as density log. In this research, density log was used to determine the weighting density function, delineate the multiple layers and correlate with the gravity-density downward variation for predicting the mineral depth using the Fourier transform method.

The results show that the projected residual gravity anomaly at depth between 2015 m and 2170 m depicts all the gravity features that are clearly associated with that on the original plane and also show minimal distortion of the shape of the anomalies. The anomalous mass lies between these depths. The downward continuation depths obtained from the gravity model were compared with that obtained from reflection seismic observation from the study area and the relative error percent were 1.37 % and 0.46 % respectively.

References

Blakely R. J., 1996. Potential Theory in Gravity and Magnetics Application. Cambridge, United Kingdom: Cambridge University Press., 441p.

Byerly P. E., 1965. Convolution filtering of gravity and magnetic maps. Geophysics 30, 281—283.

Clarke G. K. C., 1969. Optimum second derivative and downward continuation filters. Geophysics 34, 424—437.

Dean W. C., 1958. Frequency analysis for gravity and magnetic interpretation. Geophysics 23, 97—127.

Dobrin M. B., Savit C. H., 1988. Introduction to Geophysical Prospecting. 4th Edition. Singapore: McGrawHill Book Co., 867 p.

Fuller B. D., 1967. Two-dimensional frequency analysis and design of grid operators. Mining Geophysics 2, 658—708.

Grant F. S., West G. F., 1987. Interpretation Theory in Applied Geophysics. Toronto: McGrawhill Book Company, 584 p.

Henderson R., 1960. A comprehensive system of automatic computation in magnetic and gravity interpretation. Geophysics 25, 569—585.

Mesko A., 1965. Some notes concerning the frequency analysis for gravity interpretation. Geophys. Prosp. 13, 475—488.

Peters L. J., 1949. The direct approach to magnetic interpretation and its practical application. Geophysics 14, 290—320.

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Published

2016-08-01

How to Cite

Epuh, E. E., Olaleye, J. B., & Omogunloye, O. G. (2016). Predicting Depth of Mineral Deposit using Gravity-Density Downward Correlation by Fourier Transform. Geofizicheskiy Zhurnal, 38(5), 137–145. https://doi.org/10.24028/gzh.0203-3100.v38i5.2016.107827

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