1887
Volume 4 Number 3
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

An attempt is made to interpret some magnetic anomalies in Denmark and Northern Holland. As the thickness of the nonmagnetic sediments in the areas is large, the interpretation must depend mainly on computational procedures, i.e. a combined analysis of gravimetric and magnetic anomalies, assuming that the two kinds of anomalies originate in the same body.

The mathematic basis of these computations is presented, and from this conclusions are drawn about both direction and intensity of the magnetism in the underlying rocks.

On this basis, the magnetic declination in these rocks appears to be westerly for all the areas considered. This declination is, of course, a combined effect of induced and remanent magnetization. The corresponding magnetic inclination is smaller than the inclination existing at the surface, and in several cases the magnetic inclination in the rocks is clearly negative, i.e. directed upwards.

Both the declination and the inclination in the rocks vary considerally from one locality to another. However, if we assume that these varying results are caused mainly by different ratios of the strengths of induced and remanent magnetism, the directions of remanent magnetism group themselves around a fixed declination, about ‐160°, and a fixed inclination, about ‐60°.

Estimates of the magnitude of both induced and remanent intensities of magnetization are contained in these conclusions. In both cases the magnitude may be of the order 10‐2 cgs units.

The hypothetical geomagnetic poles corresponding to this direction of natural remanence are situated near the central part of the northern Siberian coast and near that part of the Antarctic coast just south of South America.

Loading

Article metrics loading...

/content/journals/10.1111/j.1365-2478.1956.tb01407.x
2006-04-27
2024-03-28
Loading full text...

Full text loading...

References

  1. Ackerman, H. A., and Dix, C. H., 1955, The First Vertical Derivative of Gravity, Geophysics, XX, 148–154.
    [Google Scholar]
  2. Almond, M., See Clegg etc.
  3. Baranov, V., 1953, Calcul du gradient vertical du champ de gravité ou du champ magnétique mesuréà la surface du sol, Geophys. Prosp., I, 171–191.
    [Google Scholar]
  4. Baranov, V., and Tassencourt, J., 1954, Some Remarks on the Errors in Calculation of the Vertical Gradient of Gravity, Geophys. Prosp., II, 285–289.
    [Google Scholar]
  5. du Bois, P. M., 1955, Palaeomagnetic Measurements of the Keweenawan, Nature, 176, 506–507.
    [Google Scholar]
  6. Bruckshaw, J.Mc, G., 1954, Rock Magnetism - Some recent Developments, Science Progress, 42, No. 167, 406–418.
    [Google Scholar]
  7. Bullard, E., and Gellman, H., 1954, Homogeneous Dynamos and Terrestrial Magnetism, Phil. Trans. Roy. Soc, Ser. A, Vol. 247, 213–278.
    [Google Scholar]
  8. Charlesworth, H. A. K., See Hospers etc.
  9. Clegg, J. A., Almond, M., and Stubbs, P.H.S., 1954, The Remanent Magnetism of some Sedimentary Rocks in Britain, Philos. Mag., 45, 583–598.
    [Google Scholar]
  10. Day, A. A., and Runcorn, S. K., 1955, Polar Wandering: Some Geological, Dynamical and Palaeomagnetic Aspects, Nature, 176, 422–426.
    [Google Scholar]
  11. Einarsson, T., and Sigurgeirsson, T.1955, Rock Magnetism in Iceland, Nature, 175, p. 892.
    [Google Scholar]
  12. Eötvös, R., 1907, Bestimmung der Gradienten der Schwerkraft und ihrer Niveauflächen mit Hilfe der Drehwage. Aus dem ersten Band der Abhandlungen der XV. Algemeinen Konferenz der Erdmessung in Budapest, 1906.
  13. Garland, G. D., 1951, Combined Analysis of Gravity and Magnetic Anomalies, Geophysics, XVI, 51–62.
    [Google Scholar]
  14. Gellman, H., See Bullard etc.
  15. Graham, J. W., 1955, Evidence of Polar Shift since Triassic Time, Jour. Geophys. Research, 60, 329–348.
    [Google Scholar]
  16. Haalck, H., 1929, Zur Frage der Erklärung der Kursker magnetischen und gravimetrischen Anomalie, Gerlands Beitr. Geophysik, 22, 241–255 & 385–399.
    [Google Scholar]
  17. Hofmann, W., 1949, Uber Anvendungen einer Formel zur Berechnung der Vertikalgradienten der Schwere, Geofisica Pura e Appl., XIV, 145–162.
    [Google Scholar]
  18. Hospers, J., 1954, Magnetic Correlation in Volcanic Districts, Geol. Mag., XCI, 352–360.
    [Google Scholar]
  19. Hospers, J., and Charlesworth, H. A. K., 1954, The Natural Permanent Magnetization of the Lower Basalts of Northern Ireland, Royal Astron. Soc. Monthly Notices, Geophys. supp., 7, 32–43.
    [Google Scholar]
  20. Koenigsberger, J. G., 1938, Natural Residual Magnetism of Eruptive Rocks, Terrestrial Magnetism and Atm. Elect., 43, 119–130 & 299–320.
    [Google Scholar]
  21. Kosbahn, B., 1949, Uber die Berechnung sämtlicher Feldgrössen aus der Vertikalintensität und deren Anwendung auf die Auswertung von Schwerebildern, Geofisica Pura e Appl., XV, 27–36.
    [Google Scholar]
  22. Lundbak, A., 1954, Magnetic Properties of Basement Rocks, Internat. Geol. Cong., Algiers, 19th sess, Comptes Rendus, Sec. 9, fasc. 9, 135–149.
    [Google Scholar]
  23. Nagata, T., 1943, The Natural Remanent Magnetism of Volcanic Rocks and Its Relation to Geomagnetic Phenomena, Tokyo Univ. Earthquake Research Inst. Bull., XXI, 1–196.
    [Google Scholar]
  24. Nagata, T., 1953, Rock‐Magnetism Ird Ed., Maruzen Co., Tokyo .
    [Google Scholar]
  25. RuncornS. K., 1955, Palaeomagnetism of Sediments from the Colerado Plateau, Nature, 176, 505–506.
    [Google Scholar]
  26. Runcorn, S. M., See also Day etc.
  27. Sigurgeirsson, T., See Einarsson etc.
  28. Stubbs, P. H. S., See Clegg etc.
  29. Tassencourt, J., See Baranov etc.
  30. Werner, S., 1945, Determinations of the Magnetic Susceptibility of Ores and Rocks from Swedish Iron Ore Deposits, Sveriges Geologiska Undersökning, Ser. C, No. 472.
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journals/10.1111/j.1365-2478.1956.tb01407.x
Loading
  • Article Type: Research Article

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