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, cilt.14, ss.123-143, 2005 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 14 Konu: 2
  • Basım Tarihi: 2005
  • Dergi Adı: TURKISH JOURNAL OF EARTH SCIENCES
  • Sayfa Sayıları: ss.123-143

Özet

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.