(a) Geological map of Sri Lanka with litho tectonic subdivision (after Cooray, 1994). Sampling locality is shown by a star. Reported UHT localities are shown by circles: 1. Osanai (1989): T N 900 °C; 2. Kriegsman and Schumacher (1999): T = 830 °C; 3. Sajeev and Osanai (2004a): T = 950 °C: 4. Sajeev and Osanai (2004b): T = 1150 °C; 5. Osanai et al. (2006): T N 1000 °C and 6. Sajeev et al. (2007): T = 925 °C. (b) Detailed geological map of the sampling area around Nawalapitiya (central part of the Highland Complex), modified after the published map of the Geological Survey Department of Sri Lanka (1996).