COMBINED ANALYSIS OF GRAVIMETRIC AND MAGNETIC ANOMALIES AND SOME PALAEOMAGNETIC RESULTS*

• Published in: Geophysical Prospecting
• Main Author: LUNDBAK, ASGER
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1956
• Subjects: Antarc*; Antarctic
• Online Access: http://dx.doi.org/10.1111/j.1365-2478.1956.tb01407.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2478.1956.tb01407.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2478.1956.tb01407.x

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.