INTERNATIONAL GEOLOGY REVIEW, vol.43, no.8, pp.711-721, 2001 (SCI-Expanded)
Mainly calc-alkaline, andesitic, and dacitic volcanics from different late Miocene-Pliocene eruption centers crop out WSW of Konya, and locally are interbedded with lacustrine sediments. Hydrothermal alteration within these rocks is widespread. In addition to kaolinite, other major alteration products include halloysite, alunite, cristobalite, quartz, illite, montmorillonite, and zeolite-group minerals. Based on the cristobalite-quartz relationship, the kaolinization temperature is estimated as similar to 100 degreesC.