Open AccessAn Attempt to Determine Ancient Field Intensities Using Lavas Containing Single Phase Titanomagnetites
Author(s) -
Sanver M.
Publication year - 1968
Publication title -
geophysical journal of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0016-8009
DOI - 10.1111/j.1365-246x.1968.tb00218.x
Subject(s) - thermomagnetic convection , geology , internal consistency , volcanic rock , mineralogy , consistency (knowledge bases) , igneous rock , phase (matter) , field (mathematics) , petrology , geochemistry , magnetic field , volcano , chemistry , medicine , clinical psychology , physics , geometry , mathematics , organic chemistry , quantum mechanics , psychometrics , pure mathematics
Summary An attempt to use unoxidized volcanic rocks for ancient field intensity determinations is described. Slightly oxidized, exsolved and highly oxidized rocks were also used in order to compare the suitability of different kinds of rock. Typical samples of each group were selected by ore microscopic and thermomagnetic analysis. The following conclusions were drawn: (i) the unoxidized and highly oxidized rocks satisfied thermomagnetic analysis test. The slightly oxidized samples were most effected during heating; (ii) the internal consistency for the results obtained from unoxidized rocks was as good as highly oxidized rocks. The slightly oxidized samples exhibited the best internal consistency although they were known to be the most affected by heating. Therefore, it can be said that internal consistency itself is not a good measure of the reliability of the results; (iii) repeated thermomagnetic experiments at low temperature (T=300 °C) can be used to distinguish the unoxidized rocks from slightly oxidized rocks; (iv) initial susceptibility measurements are more sensitive to any change caused by heating than high field measurements.