1887
Volume 14, Issue 1
  • ISSN: 0812-3985
  • E-ISSN: 1834-7533

Abstract

Abstract

Conventional contour maps of aeromagnetic data are often unsatisfactory for showing low amplitude anomalies or the more subtle changes in patterns associated with basement faulting. Simple one-dimensional filtering and differentiating techniques are used to obtain maps of the second horizontal derivative of magnetic intensity for the Broken Hill area, in order to enhance local features and reduce the effects of regional gradients. The second derivative is given as a three-level line-printer plot (maxima, minima and near-zero values), which minimises the contrast between areas of high and low magnetic relief. Closely spaced anomalies are resolved and trends related to basement faulting can also be inferred from the derivative maps. Lineations which are possibly several tens of kilometres in extent, and oriented mainly in northeasterly and northwesterly directions, may subdivide the basement of the Willyama Complex into a mosaic of blocks.

© 1983 ASEG
Loading

Article metrics loading...

/content/journals/10.1071/EG983011
1983-03-01
2026-01-17

  • From This Site

    /content/journals/10.1071/EG983011
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Aarnisalo, J. (1968), ‘Use of satellite pictures for determining major shield fractures relevant for ore prospecting, northern Finland’, Geol. Surv. Finland, Rept. Invest. No. 21, 59 pp.
  2. Akima, H. (1972), ‘Interpolation and smooth curve fitting based on local procedures’, Comm. Assoc. Comput. Machin. 15, 914-18.
  3. Boyd, D. M. (1967), ‘The contribution of airborne magnetic surveys to geological mapping’, in L. W. Morley (ed.), Mining and Groundwater Geophysics. Geol. Surv. Can., Dept. Energy, Mines & Resources, Econ. Geol. Rept. No. 26, 213-27.
  4. Glen, R. A., Laing, W. P., Parker, A. J. & Rutland, R. W. R. (1977), ‘Tectonic relationships between the Proterozoic Gawler and Willyama orogenic domains, Australia’, J. Geol. Soc. Aust. 24, 125-50.
  5. Hills, E. S. (1956), ‘A contribution to the morphotectonics of Australia’, J. Geol. Soc. Aust. 3, 1-15.
  6. Jupp, D. L. (1976), ‘B-splines for smoothing and differentiating data sequences’, Math. Geol. 8, 243-66.
  7. Katz, M. B. (1976), ‘Lineament tectonics of the Willyama Block and its relationship to the Adelaide Aulocogene’, J. Geol. Soc. Aust. 23, 275-85.
  8. Mclntyre, J. I. (1979), ‘Aeromagnetics - an effective geological mapping aid for the Willyama Complex?’, Bull. Aust. Soc. Explor. Geophys. 10, 42-53.
  9. Mclntyre, J. I. (1980), ‘Magnetic marker horizons in the Willyama Complex – second derivative maps from the BMR 1975 detailed Broken Hill aeromagnetic survey’, Geol. Surv. New South Wales, Rept. No. GS1980/008.
  10. Mclntyre, J. I. (1981), ‘Accurate display of fine detail in aeromagnetic data’. Bull. Aust. Soc. Explor. Geophys. 12, 82-8.
  11. Mclntyre, J. I. & Wyatt, B. W. (1978), ‘Contributions to the regional geology of the Broken Hill area from geophysical data’, B.M.R. J. Aust. Geol. Geophys. 3, 265-80.
  12. O’Callaghan, J. F., Graetz, R. D. & O’Sullivan, K. N. (1980), ‘The Broken Hill image-based geographic information system’, Proc. URPIS 8 (Symp. on Urban and Regional Planning Information Systems), Surfers Paradise, Nov. 1980.
  13. O’Driscoll, E. S. T. (1968), ‘Notes on the structure of the Broken Hill Lode, and its tectonic setting’, in M. Radmanovich & J. T. Woodcock (eds), Broken Hill Mines - 1968. Aust. Inst. Min. Metal. Monog. No. 3, 87-102.
  14. Rosenfeld, A., Thurston, M. & Lee, Y. (1972), ‘Edge and curve detection: Further experiments’, I.E.E.E. Trans. Comput. C-21, 677-715.
  15. Stevens, B. P. J., Barnes, R. G., Klingner, D., Marjoribanks, R. W. & Plimer, I. R. (1976), ‘Excursion guide 1B’, Broken Hill Ore Deposits. 25th Intl. Geol. Cong., Sydney.
  16. Stewart, I. C. F. & Boyd, D. M. (1977), ‘Computer processing of aeromagnetic data’, Proc. 15th APCOM Symposium (Applications of Computers and Operational Research in the Mineral Industries), Brisbane, July 1977, 199-207.
/content/journals/10.1071/EG983011
Loading
  • Article Type: Research Article
Keyword(s): aeromagnetic; anomalies; Broken Hill; enhancement; lineation; magnetic; second derivative; trend

Most Cited This Month Most Cited RSS feed

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