Magnetic properties of pyrrhotite

144

interpreter, and therefore an alternative structure mapping will be presented.

PALAEOMAGNETISM SKANE, SOUTHERN

and objective

method

OF JURASSIC--CRETACEOUS SWEDEN

to achieve

BASALTS

FROM

G. BYLUND

Palaeomagnetic

Laboratory,

inst. Of Geology,

Siilvegatan

13, S-223 62 Lund (Sweden)

The basalts of Skane are situated in the central part of the province, close to the intersection of two prominent tectonic lineaments, the Fennoscandian Randzone (the Tomquist Line) and the Protogine Zone. K-Ar datings of the basalts give Upper Jurassic to Lower Cretaceous ages. They are unaffected by high temperature oxidation but there are indications of low temperature oxidation of the titanomagnetites that carries the natural remanent magnetization. The basalts contain stable magnetic components of both normal and reversed polarity. The combined mean pole, from 15 sites, is situated at lat. 64”N, long. 96”E, d,= X2!“,d, = 14”.

MAGNETIC STEN-_iKE

PROPERTIES

OF PYRRHOTITE

ELMING

Dept. of Applied

Geophysics,

University

of LuleB, Luled (Sweden)

This investigation includes about 100 samples of pyrrhotite from different geological environments, mainly in the Skelleftea ore district. Hardness of remanence, anisotrophy of susceptibility and Q-values were estimated. By determining the anisotropy of susceptibility of pyrrhotite in a fold structure the relation between orientation of the axis of minimum susceptibility and stress is shown. Magnetic properties of pyrrhotite in general and differences in properties of pyrrhotite from different geological environments will be discussed.

THE PLAUSIBILITY OF SOME DEEP STRUCTURE SKELLEFTE FIELD IN NORTHERN SWEDEN THOMAS

ENMARK

University

of LuleB, S-951 87 Luled (Sweden)

It is a well-known

MODELS IN THE

fact that if a model fits, for example,

gravity or magnetic