Magnetic Grains in Bombay Columnar Basalts

Abstract

THE origin of columnar jointing in basalt has been discussed by several authors1, but the origin of many features of the columnar basalts is still controversial. Some magnetic studies of individual columns have been made by Brown et al.2 to detect any susceptibility anisotropy and by Symons3 to find any changes in the magnetic and petrological properties across a column. Simple magnetic techniques4,5 have recently been developed for granulometric studies and these have been used to investigate the columnar basalts of Bombay. We have found a systematic variation in the magnetic properties which could provide more information about the formation of these basalts.