Occurrence of Ca-Fe silicate minerals with zeolites in basalt cavities at Bombay, India
Wise, William S.; Moller, William P.
European Journal of Mineralogy Volume 2 Number 6 (1990), p. 875 - 884
published: Dec 19, 1990
manuscript accepted: Sep 10, 1990
manuscript received: Mar 7, 1990
ArtNo. ESP147050206014, Price: 29.00 €
Abstract Cavities in altered basalts, exposed by the Khondivilli Quarry near Bombay, India, contain prehnite, chlorite, laumontite, quartz, and calcite, associated with at least on of several Ca-Fe silicate minerals: julgodite- (Fe2+), ilvaite, babingtonite, or hydroandradite. The composition of each of these minerals is near the ferric iron end member composition. Because the surrounding rock has been replaced by chlorite with minor pyrite, cavity fluids must have developed substantially higher oxygen fugacities, in order to crystallize the various iron silicate minerals. Fluid inclusion studies and depth estimates indicate that the temperature and pressure of formation was about 200 °C and 500 bars.