| Paper No. 163-0 | ||
| DAMAVAND VOLCANO, NORTHERN IRAN: MORPHOLOGY AND SEDIMENTARY RECORD | ||
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BERZINS, Reinis1, DAVIDSON, Jon2, HASSANZADEH, Jamshid3, BASHUKOOH, Behrooz3, and STOCKLI, Daniel F.4, (1) Earth and Space Sciences, Univ of California, Los Angeles, 3806 Geology Building, 595 Charles Young Drive, Los Angeles, CA 90095-1567, rberzins@ucla.edu, (2) Department of Geological Sciences, University of Durham, Science Laboratories, South Road, Durham, DH1 3LE, United Kingdom, (3) Department of Geology, Univ of Tehran, PO Box 14155-6466, Tehran, Iran, (4) Geology Department, Univ of Kansas, 1475 Jayhawk Boulevard, 120 Lindley Hall, Lawrence, KS 66045-7613 Damavand Volcano is an isolated, >350km3 Quaternary composite cone rising 5,670m in the Alborz Mountain Range north of Tehran. Morphological and sedimentological observations, mapping, and U-He dating of apatite phenocrysts have been used to constrain the history of the volcano. The slopes of the volcano comprise trachyandesite lava flows partially overlain by reworked pyroclastic fall deposits. Volcaniclastic sediments are well exposed in cliff-sections and subsidiary valleys along a major N-S drainage, the Haraz River. The exposed sediments consist of fluvial and debris flow deposits, containing mainly clasts of lava and minor basement material. One significant ignimbrite unit has been identified, though pyroclastic eruptions were apparently minor and infrequent. Debris avalanche deposits suggest that one or more sector collapse events shaped the edifice. Local geomorphology has been strongly affected by the formation of the volcano, as erupted products are the main source material for the sediments. A large proportion of the sediments has been eroded into the Haraz River and away from the area towards the Caspian Sea. The sedimentary record of the volcano's growth and evolution is thus greatly fragmented. Two periods of eruptive activity have been identified (1.78Ma-800ka and 500ka-7.3ka), separated by a period of quiescence. During this time of inactivity, the hydrothermally-altered material in the core of the volcano was exposed and rapidly eroded because of its non-resistant nature. The eruptive style has remained the same throughout the volcano's two million year history despite one or more sector collapse events and the formation of a second cone overlying the old eroded cone. | ||
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GSA Annual Meeting, November 5-8, 2001
General Information for this Meeting | ||
| Session No. 163--Booth# 131 Volcanology (Posters) Hynes Convention Center: Hall D 8:00 AM-12:00 PM, Thursday, November 8, 2001 | ||
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