List of Articles pyroclastic

• Open Access Article
  • Abstract Page
  • Full-Text
  
  1 - Comparison of pyroclastic units (pumice & lahar) in mallar and reyneh valleys at Damavand volcano
  Amirhoushang Shirazi Manuchehr Farajzadeh
  Main objective of this research is comparison between pyroclastic of Malar and Raynah valleys in Yakhar basin in south-east of  Damavand volcano. studing of pyroclastic is very important in recognition of Dmavand volcano.this research is based on descriptive &ndash More

  Main objective of this research is comparison between pyroclastic of Malar and Raynah valleys in Yakhar basin in south-east of  Damavand volcano. studing of pyroclastic is very important in recognition of Dmavand volcano.this research is based on descriptive – analytical and using Rayneh Topographic map and Geological map of Damavand, G.P.S AND G.I.S Software.A characteristic of the Reyneh deposite is that clasts below 10 cm are mostly light grey and vescular when broken open, while most larger clasts are dark grey to black.Mallar deposite is whiter than Ryneh pumice most of mallar pumices are fall but most of reyenah pumices are flow. .volume of lahar is more in reyenah. Manuscript profile
• Open Access Article
  • Abstract Page
  • Full-Text
  
  2 - Using Wind Data to Predict the Risk of Volcanic Eruption: An Example from Damavand Volcano, Iran
  M. Mortazavi R.S.J. Sparks
  Damavand volcano is located 60 km to the East North- East of Tehran. It is a dormant stratovolcano outcrop in the Alborz Mountains of northern Iran and is the highest mountain (5670 m) in the Middle East and West Asia. Mazandaran Province, one of the most populous provi More

  Damavand volcano is located 60 km to the East North- East of Tehran. It is a dormant stratovolcano outcrop in the Alborz Mountains of northern Iran and is the highest mountain (5670 m) in the Middle East and West Asia. Mazandaran Province, one of the most populous provinces by population density, Semnan and Gorgan provinces further east are neighbours of the Damavand. Volcanism in Damavand goes back to at least 1 Ma year ago and the latest eruption occurred 7000 years ago. Tephra dispersal in volcanoes strongly depends on atmospheric information in particular wind direction and velocity in stratospheric and tropospheric levels. We present an analysis of wind data to assess the hazards that would result from tephra fall in the cities and provinces neighbouring Damavand. Atmospheric data were provided from the Meteorological stations at Mehr-Abaad airport, Wyoming University and global data sets. We examine wind data from 17 standard pressure levels which cover from 5700 meter (Damavand peak) to 31 km above sea level. If Damavand moved into a state of unrest then a major explosive eruption is a plausible scenario that should be planned for. The results confirm that the area to the south and east of volcano will be affected by tephra. Communities around the southern and eastern flanks of the volcano also have high hazard. Wind data also shows the effects of season on dispersal of tephra from a 25 km high eruption column. Tephra dispersal is dominantly towards the east in all seasons for eruption columns up to 20 km above sea level. Mazandran, Semnan and Gorgan providence could be affected in this case. At 25 km- high eruption column and during the summer there are easterly winds; therefore, the tephra would disperse toward the east. In this case Tehran could experience a tephra fall deposit Manuscript profile
• Open Access Article
  • Abstract Page
  • Full-Text
  
  3 - Determination of the Geological Conditions During the Formation of Kaolinite and Bentonite Deposits in NW Alborz Mountains (Pirkoh-Deylaman) of Iran and the Study of Its Practical Properties for Use in the Porcelain Industry
  Farzad Asadi Ali Darvishzadeh Ali Montezeri
  The area under study is located in northern Iran at 36° 47’ latitude and 50° 12' longitude. It is 15 km from southeastern Deylaman. Petrological study of the kaolin mother rock (Eocene age) under a microscope shows that the rock is vitric tuff with a rhyol More

  The area under study is located in northern Iran at 36° 47’ latitude and 50° 12' longitude. It is 15 km from southeastern Deylaman. Petrological study of the kaolin mother rock (Eocene age) under a microscope shows that the rock is vitric tuff with a rhyolitic combination containing falcated and embowed glass shards. The thickness of the layer is approximately 20 meters, formed unconformably on a layer of conglomerate with a thickness of approximately 400 meters. Because the shards have a falcated and embowed shape and the percentage of reworked material within them is low, the tuff can be considered a type of pyroclastic airfall. The results of the study prove that ash falling occurred in the water. The stratabound layers show syngenetic deposits to be the main factor in the formation of the clay, bound as a result of alterations. Manuscript profile