Stratigraphy of the volcanic products around Nemrut caldera: Implications for reconstruction of the caldera formation

Karaoglu O., Ozdemir Y., Tolluoglu A., Karabiyikoglu M., Kose O., Froger J.

TURKISH JOURNAL OF EARTH SCIENCES, vol.14, no.2, pp.123-143, 2005 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 14 Issue: 2
  • Publication Date: 2005
  • Journal Name: TURKISH JOURNAL OF EARTH SCIENCES
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, TR DİZİN (ULAKBİM)
  • Page Numbers: pp.123-143
  • Keywords: Nemrut, caldera, ignimbrite, pyroclastics, East Anatolia volcanism, EASTERN ANATOLIA, TURKEY, PLATEAU, NEOTECTONICS, IGNIMBRITES, TECTONICS, EVOLUTION, WESTERN
  • Middle East Technical University Affiliated: No

Abstract

The volcanological development of the Nemrut stratovolcano, located near the southwestern tip of Lake Van in eastern Turkey, is subdivided into three stages: pre-caldera, post-caldera and late stages. Two ignimbrite flows have been recognized in the pre-caldera stage. The earlier of the two occurred after basaltic lavas formed along extensional fissures. The latter, which forms the main subject of this paper, was a major flow associated with the development of the Nemrut caldera. The pyroclastic deposits of the Nemrut volcano in the pre-caldera stage are divided into three phases on the basis of palaeosols that separate them. The first phase includes plinian pumice falls and a pyroclastic flow deposit. The major ignimbrite occurs in the second pyroclastic phase and is here subdivided into three sub-layers based on colour, internal grading, size of pumice and lithic clasts, and the degree of welding. The third and last pyroclastic phase was dominated by plinian pumice and ash-fall deposits.