Titanium in quartz as a record of ultrahigh-temperature metamorphism: the granulites of Karur, southern India

K. Sato, M. Santosh
2007 Mineralogical magazine  
The occurrence is reported of spectacular oriented needles of rutile within quartz veins and pods in granulite-facies rocks that have undergone partial melting under ultrahigh-temperature (UHT) conditions in the Karur region in southern India. Laser Raman spectroscopy and electron microprobe analysis confirm that (1) the mineral inclusions within quartz are pure rutiles, and (2) a second category of quartz contains pure hematite inclusions. The rutile never coexists with the hematite inside the
more » ... hematite inside the same quartz specimens. Fluid inclusions in the quartz are characterized as a CO 2 + H 2 O mixture. Application of two geothermometric calibrations utilizing Ti in quartz yields minimum estimates of~1190ºC, suggesting the formation of the rutile-quartz under UHT metamorphic condition. It is proposed that such Ti-rich quartz segregations could be another indicator for extreme crustal metamorphism at very high temperatures.
doi:10.1180/minmag.2007.071.2.143 fatcat:ph3n65elkjaw5ec6qqtjoz5l6i