Variation of Palaeomagnetic Stability and Other Parameters in a Vertical Traverse of a Single Icelandic Lava
Article
Wilson, RL, Haggerty, SE, Watkins, ND. (1968). Variation of Palaeomagnetic Stability and Other Parameters in a Vertical Traverse of a Single Icelandic Lava
. 16(1), 79-96. 10.1111/j.1365-246X.1968.tb07137.x
Wilson, RL, Haggerty, SE, Watkins, ND. (1968). Variation of Palaeomagnetic Stability and Other Parameters in a Vertical Traverse of a Single Icelandic Lava
. 16(1), 79-96. 10.1111/j.1365-246X.1968.tb07137.x
An intensive study has been made of 30 samples from within, and two bakes samples from below a single Tertiary basalt in Eastern Iceland. The samples are spaced along a measured vertical traverse from bottom to top. The lava is 16·8 m thick, and is reversely magnetized. The quantities measured for each core were: Oxidation state as revealed by microscope studies in polished sections of the iron‐titanium oxide. Oxidation state of the whole rock as determined by FeO and Fe2O3 analyses. Titanomagnetite and separate ilmenite grain sizes. Magnetic susceptibility. Saturation magnetization. Curie points and total heating curve in a strong magnetic field. Natural magnetization after demagnetization in several alternating fields. Koenigsberger's Q factor, slightly modified. A new measure of the resistance of the specimen to alternating field demagnetization, the ‘stability factor’. The position of the core above the base of the lava. The above quantities vary greatly with position in the lava. The results of these measurements show the relationships of these variables to each other; in particular how the palaeomagnetic stability depends on oxidation state of the iron‐titanium oxides. Stability is high in the lower two‐thirds of this lava, and not just at the chilled margins. Two anomalous results are (1) that the Curie point is virtually constant regardless of oxidation state (unlike some other lavas), and (2) that the whole rock oxidation state measured by Fe2O3/(2FeO + Fe2O3) does not correlate simply with the oxidation state of the iron‐titanium oxides as seen in the microscope. 1968 Royal Astronomical Society
