This article deals with the introduction and explanation of the two nuéeardentes of “Mue’el Valley” and “Shirvandareh Valley” which are one type of the pyroclastic flows of Sabalan volcano. One of the features of nuéeardente in these two valleys is the presence of large blocks in upstream of valley and the abundance of ash in downstream which it has happened in one stage in Mue’el and in several stages in Shirvandareh Valley. Considering the antiquity of the great Sabalan volcano and numerous changes that have happened during these long years in the region, determining the temperature of nuéeardente was impossible. But what could be mentioned as a sign of high temperature because of nuéeardente is the presence of rust ground mass on piece levels which indicate hot water steam (500°C to 600°C). Also puzzle breakings like those in these rocks should be the result of severe explosion blast and very fast movements of nuéeardente that has broken these rocks instantly. These nuéeardentes are peléan type and they are more or less synchronous, and the main reason could be the huge explosion which happened because of the second caldra’s subsidence. By comparing deposits of the two nuéeardentes of Mue’el Valley and Shirvandareh Valley, it is observed that the extent, thickness, and size of blocks are higher in Shirvandareh than those in Mue’el Valley. Also considering higher levels of pieces’ adherence and hardness of deposits, it can be concluded that the temperature of this complex was higher than that of Mue’el Valley, and in general the power of Shirvandareh’s nuéeardente is more than the Mue’el Valley’s.
References
[1]
Didon, J. and Gemain, Y.M. (1976) Le Sabalan, Volcan Plio-quaternair de l’Azerbaidjan oriental (Iran); etude geologiqueetpetrographique de l’edifice et de son environnement regional. These de 3eme Cycle, Univ. Grenoble.
[2]
Ghalamghash, J., Mousavi, S.Z., Hassanzadeh, J. and Schmitt, A.K. (2016) Geology, Zircon Geochronology, and Petrogenesis of Sabalan Volcano (Northwestern Iran). Journal of Volcanology and Geothermal Research, in Press.
https://doi.org/10.1016/j.jvolgeores.2016.05.001
[3]
Mousavi, S.Z. (2013) Volcanology and Petrology of Sabalan Volcano, North West of Iran. Ph.D. Dissertation, Department of Geology of Science and Research Branch, Islamic Azad University, Tehran.
[4]
Shahbazi Shiran, H. and Shafaii Moghadam, H. (2014) Geochemistry and Petrogenesis of the Sabalan Plio-Quaternary Volcanic Rocks: Implication for Post-Collisional Magmatism. Irananin Journal of Crystallography and Mineralogy, 22, 57-68.
[5]
Emami, M.H. (2000) Magmatism in Iran. The Organization of Geology and Mineral Exploration of Country.
[6]
Ogburn, S.E., Loughlin, S. and Calder, E.S. (2015) The Association of Lava Dome-Growth with Majorexplosive Activity (VEI ≥ 4): Dome Haz a Global Dataset. Bulletin of Volcanology, 77, 1-17. https://doi.org/10.1007/s00445-015-0919-x
[7]
Alberti, A.A. and Stolfa, D. (1973) First Data on the Savalan Volcano (Eastern Azerbaijan, Iran): The Upper Series. Rendicontidella Societa Italiana di Mineralogia e Petrologia, 29, 369-385.
[8]
Alberti, A.A., Comin-Chiaramonti, G., Sinigoi, S. and Zerbi, M. (1976) On the Magmatism of the Savalan Volcano (North West Iran). Rendicontidella Societa Italiana di Mineralogia e Petrologia, 32, 156-168.
Sulpizio, R., Dellino, P., Mele, D. and La Volpe, L. (2008) Generation of Pyroclastic Density Currents from Pyroclastic Fountaining or Transient Explosions: Insights from Large Scale Experiments. IOP Conference Series: Earth and Environmental Science, 3, 12-20.
https://doi.org/10.1088/1755-1307/3/1/012020
[11]
Lacroix, A. (1904) La Montagne Peléeetseséruptions. Masson et Cie, Paris.
[12]
Lacroix, A. (1930) Remarques sur les materiaux de projection des volcan et sur la genese des rochespyroclastiqueq’ill constituent. Bulletin de la Société Géologique de France, Livre Jubilaire Centenarie, 11, 431-472.
Calder, E.S., Lavallée, Y., Kendrick, J.E. and Bernstein, M. (2015) Lava Domeeruptions. In: Sigurdsson, H., Houghton, B., Rymer, H., Stix, J. and McNutt, S., Eds., Encyclopedia of Volcanoes, 2nd Edition, Academic Press, San Diego, 343-362.
https://doi.org/10.1016/B978-0-12-385938-9.00018-3
[15]
Carey, S. and Sigurdsson, H. (1985) The May 18, 1980 Eruption of Mount St. Helens 2. Modeling of Dynamics of the Plinian Phase. Journal of Geophysical Research, 90, 2948-2958. https://doi.org/10.1029/JB090iB04p02948
[16]
Carey, S. and Sigurdsson, H. (1989) The Intensity of Plinian Eruptions. Bulletin of Volcanology, 51, 28-40. https://doi.org/10.1007/BF01086759
[17]
Jousset, P., Pallister, J. and Surono (2013) The 2010 Eruption of Merapi Volcano. Journal of Volcanology and Geothermal Research, 261, 1-6.
https://doi.org/10.1016/j.jvolgeores.2013.05.008
[18]
Pallister, J.S., Schneider, D.J., Griswold, J.P., Keeler, R.H., Burton, W.C., Noyles, C., Newhall, C.G. and Ratdomopurbo, A. (2013) Merapi 2010 Eruptio: Chronology and Extrusion Rates Monitored with Satellite Radar and Used in Eruption Forecasting. Journal of Volcanology and Geothermal Research, 261, 144-152.
https://doi.org/10.1016/j.jvolgeores.2012.07.012
